210 results on '"Smith ZA"'
Search Results
2. Complete absence of the posterior arch of C1: Case report
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Dahdaleh, NS, primary, Dlouhy, BJ, additional, Khanna, R, additional, and Smith, ZA, additional
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- 2014
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3. Outcomes in critical care delivery at Jimma University Specialised Hospital, Ethiopia.
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Smith, Za, Ayele, Y, McDonald, P, and Smith, Z A
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The aim of this study was to assess outcomes following intensive care unit (ICU) admissions at Jimma University Specialised Hospital, Ethiopia. This was a retrospective observational study. Data were collected regarding all ICU admissions and discharges during a 12-month period beginning August 2011. Demographic data and information regarding diagnosis, length-of-stay and outcome were gathered and data analysed. There were 370 admissions to the ICU during the study period. Median age (interquartile range) was 32.0 (22.0-47.0) years and 56.2% were males. The median length-of-stay (interquartile range) was 3.0 (1.0-7.0) days. The overall ICU mortality rate was 50.4% and major causes included trauma, cardiac disease, acute abdominal presentations, septic shock, tetanus and hysterectomy secondary to uterine rupture. Medical diagnoses accounted for 50.1% of admissions followed by surgery (43.2%) and obstetrics (5.8%). Corresponding mortality rates were 53.6, 48.0 and 42.9%, respectively. The main cause for surgical admission was trauma, with head injury carrying a mortality of 52.1%. The principal cause for medical admission was cardiac disease. In children, trauma, upper airway obstruction and communicable diseases were most common. Critical care mortality rates at this Ethiopian university hospital reflect the challenges facing critical care delivery in the developing world. Delayed presentation to hospital secondary to poor access to healthcare plays a predominant role. This is confounded by inadequate staffing, training, diagnostic and interventional limitations. Despite resource restraints, simple cost-effective measures may improve morbidity and mortality. [ABSTRACT FROM AUTHOR]
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- 2013
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4. Paradigm changes in spine surgery: evolution of minimally invasive techniques.
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Smith ZA, Fessler RG, Smith, Zachary A, and Fessler, Richard G
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Minimally invasive spine surgery (MISS) techniques were developed to address morbidities associated with open spinal surgery approaches. MISS was initially applied for indications such as the microendoscopic decompression of stenosis (MEDS)-an operation that has become widely implemented in modern spine surgery practice. Minimally invasive surgery for MEDS is an excellent example of how an MISS technique has improved outcomes compared with the use of traditional open surgical procedures. In parallel with reports of surgeon experience, accumulating clinical evidence suggests that MISS is favoured over open surgery, and one could argue that the role of MISS techniques will continue to expand. As the field of minimally invasive surgery has developed, MISS has been implemented for the treatment of increasingly difficult and complex pathologies, including trauma, spinal malignancies and spinal deformity in adults. In this Review, we present the accumulating evidence in support of minimally invasive techniques for established MISS indications, such as lumbar stenosis, and discuss the need for additional level I and level II data to demonstrate the benefit of MISS over traditional open surgery. The expanding utility of MISS techniques to address an increasingly broad range of spinal pathologies is also highlighted. [ABSTRACT FROM AUTHOR]
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- 2012
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5. Uranium and Radium-226 in Florida Phosphate Materials
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Prince Rj, Smith Za, Roessler Ce, and Wesley E. Bolch
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Epidemiology ,Health, Toxicology and Mutagenesis ,Radiochemistry ,chemistry.chemical_element ,High resolution ,Uranium ,Mass spectrometry ,Phosphate ,Mining ,Phosphates ,Radium ,Matrix (chemical analysis) ,chemistry.chemical_compound ,chemistry ,Chemical Industry ,Florida ,Background Radiation ,Radiology, Nuclear Medicine and imaging ,Nuclide - Abstract
Input materials, products and by-products from a number of Florida phosphate mines and chemical plants were analyzed for 226Ra and 238U by high resolution gamma spectrometry. Concentrations were distinctly lower in North Florida than in Central Florida. In the matrix, the two nuclides were e
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- 1979
6. Native T1 mapping by cardiovascular resonance imaging detects subclinical cardiomyopathy in patients with systemic lupus erythematosus
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Puntmann Valentina O, D'Cruz David, Smith Zachary, Pastor Ana, Choong Peng, Carr-White Gerald, Voigt Tobias, Sangle Shirish R, Schaeffter Tobias, and Nagel Eike
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Diseases of the circulatory (Cardiovascular) system ,RC666-701 - Published
- 2013
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7. Cervical spinal cord bullet fragment removal using a minimally invasive surgical approach: a case report
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Lawton Cort D, Smith Zachary A, Sugimoto Koichi, Smith Justin S, and Fessler Richard G
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Bullet ,Gunshot wound ,Intramedullary ,Minimally invasive spine surgery ,Spinal cord ,Medicine - Abstract
Abstract Introduction We present a case of penetrating gunshot injury to the high-cervical spinal cord and describe a minimally invasive approach used for removal of the bullet fragment. We present this report to demonstrate technical feasibility of a minimally invasive approach to projectile removal. Case presentation An 18-year-old African-American man presented to our hospital with a penetrating gunshot injury to the high-cervical spine. The bullet lodged in the spinal cord at the C1 level and rendered our patient quadriplegic and dependent on a ventilator. For personal and forensic reasons, our patient and his family requested removal of the bullet fragment almost one year following the injury. Given the significant comorbidity associated with quadriplegia and ventilator dependency, a minimally invasive approach was used to limit the peri-operative complication risk and expedite recovery. Using a minimally invasive expandable retractor system and the aid of a microscope, the posterior arch of C1 was removed, the dura was opened, and the bullet fragment was successfully removed from the spinal cord. Conclusions Here we describe a minimally invasive procedure demonstrating the technical feasibility of removing an intramedullary foreign object from the high-cervical spine. We do not suggest that the availability of minimally invasive procedures should lower the threshold or expand the indications for the removal of bullet fragments in the spinal canal. Rather, our objective is to expand the indications for minimally invasive procedures in an effort to reduce the morbidity and mortality associated with spinal procedures. In addition, this report may help to highlight the feasibility of this approach.
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- 2012
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8. Sequencing of a QTL-rich region of the Theobroma cacao genome using pooled BACs and the identification of trait specific candidate genes
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Blackmon Barbara P, Ficklin Stephen P, Staton Margaret E, Ford James, Smith Zachary, Parida Laxmi, Haiminen Niina, Mockaitis Keithanne, Saski Christopher A, Feltus Frank A, Cheng Chun-Huai, Schnell Raymond J, Kuhn David N, and Motamayor Juan-Carlos
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next-generation sequencing ,QTL sequencing ,fungal disease resistance ,chocolate ,Biotechnology ,TP248.13-248.65 ,Genetics ,QH426-470 - Abstract
Abstract Background BAC-based physical maps provide for sequencing across an entire genome or a selected sub-genomic region of biological interest. Such a region can be approached with next-generation whole-genome sequencing and assembly as if it were an independent small genome. Using the minimum tiling path as a guide, specific BAC clones representing the prioritized genomic interval are selected, pooled, and used to prepare a sequencing library. Results This pooled BAC approach was taken to sequence and assemble a QTL-rich region, of ~3 Mbp and represented by twenty-seven BACs, on linkage group 5 of the Theobroma cacao cv. Matina 1-6 genome. Using various mixtures of read coverages from paired-end and linear 454 libraries, multiple assemblies of varied quality were generated. Quality was assessed by comparing the assembly of 454 reads with a subset of ten BACs individually sequenced and assembled using Sanger reads. A mixture of reads optimal for assembly was identified. We found, furthermore, that a quality assembly suitable for serving as a reference genome template could be obtained even with a reduced depth of sequencing coverage. Annotation of the resulting assembly revealed several genes potentially responsible for three T. cacao traits: black pod disease resistance, bean shape index, and pod weight. Conclusions Our results, as with other pooled BAC sequencing reports, suggest that pooling portions of a minimum tiling path derived from a BAC-based physical map is an effective method to target sub-genomic regions for sequencing. While we focused on a single QTL region, other QTL regions of importance could be similarly sequenced allowing for biological discovery to take place before a high quality whole-genome assembly is completed.
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- 2011
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9. Primary bony non-Hodgkin lymphoma of the cervical spine: a case report
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Sedrak Mark F, Smith Zachary A, and Khoo Larry T
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Medicine - Abstract
Abstract Introduction Non-Hodgkin lymphoma primarily originating from the bone is exceedingly rare. To our knowledge, this is the first report of primary bone lymphoma presenting with progressive cord compression from an origin in the cervical spine. Herein, we discuss the unusual location in this case, the presenting symptoms, and the management of this disease. Case presentation We report on a 23-year-old Caucasian-American man who presented with two months of night sweats, fatigue, parasthesias, and progressive weakness that had progressed to near quadriplegia. Magnetic resonance (MR) imaging demonstrated significant cord compression seen primarily at C7. Surgical management, with corpectomy and dorsal segmental fusion, in combination with adjuvant chemotherapy and radiation therapy, halted the progression of the primary disease and preserved neurological function. Histological analysis demonstrated an aggressive anaplastic large cell lymphoma. Conclusion Isolated primary bony lymphoma of the spine is exceedingly rare. As in our case, the initial symptoms may be the result of progressive cervical cord compression. Anterior corpectomy with posterolateral decompression and fusion succeeded in preventing progressive neurologic decline and maintaining quality of life. The reader should be aware of the unique presentation of this disease and that surgical management is a successful treatment strategy.
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- 2010
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10. Cervical spinal cord morphometrics in degenerative cervical myelopathy: quantification using semi-automated normalized technique and correlation with neurological dysfunctions.
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Muhammad F, Weber KA, Bédard S, Haynes G, Smith L, Khan AF, Hameed S, Gray K, McGovern K, Rohan M, Ding L, Van Hal M, Dickson D, Tamimi MA, Parrish T, Dhaher Y, and Smith ZA
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- Humans, Male, Female, Middle Aged, Aged, Prospective Studies, Spinal Cord Diseases diagnostic imaging, Spinal Cord Diseases pathology, Adult, Cervical Cord diagnostic imaging, Cervical Cord pathology, Magnetic Resonance Imaging, Spinal Cord Compression diagnostic imaging, Spinal Cord Compression pathology, Cervical Vertebrae diagnostic imaging
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Background Context: Degenerative cervical myelopathy (DCM) is characterized by spinal cord atrophy. Accurate estimation of spinal cord atrophy is key to the understanding of neurological diseases, including DCM. However, its clinical application is hampered by difficulties in its precise and consistent estimation due to significant variability in spinal cord morphometry along the cervical spine, both within and between individuals., Purpose: To characterize morphometrics of the compressed spinal cord in DCM patients. We employed our semiautomated analysis framework that incorporates the Spinal Cord Toolbox (SCT) and a normalization approach to effectively address the challenges posed by cord compression in these patients. Additionally, we examined the clinical relevance of these morphometric measures to enhance our understanding of DCM pathophysiology., Study Design: Prospective study., Patient Sample: This study investigated 36 DCM patients and 31 healthy controls (HCs)., Outcome Measures: Clinical scores including 9-hole peg test for hand dexterity, hand grip strength, balance, gait speed, modified Japanese Orthopaedic Association (mJOA) score, and imaging-based spinal cord morphometrics., Method: Using the generic spine acquisition protocol and our semiautomated analysis pipeline, spinal cord morphometrics, including cross-sectional area (CSA), anterior-posterior (AP) and transverse (RL) diameters, eccentricity, and solidity, were estimated from sagittal T2w magnetic resonance imaging (MRI) images using the Spinal Cord Toolbox (SCT). Normalized metrics were extracted from the C1 to C7 vertebral levels and compared between DCM patients and HC. Morphometric data at regions of maximum spinal cord compression (MSCC) were correlated with the clinical scores. A subset of participants underwent follow-up scans at 6 months to monitor longitudinal changes in spinal cord atrophy., Results: Spinal cord morphometric data were normalized against the healthy population morphometry (PAM50 database) and extracted for all participants. DCM patients showed a notable reduction in CSA, AP, and RL diameter across all vertebral levels compared to HC. MSCC metrics correlated significantly with clinical scores like dexterity, grip strength, and mJOA scores. Longitudinal analysis indicated a decrease in CSA and worsening clinical scores in DCM patients., Conclusion: Our processing pipeline offers a reliable method for assessing spinal cord compression in DCM patients. Normalized spinal cord morphometrics, particularly the CSA could have potential for monitoring DCM disease severity and progression, guiding treatment decisions. Furthermore, to our knowledge our study is the first to apply the generic spinal cord acquisition protocol, ensuring consistent imaging across different MRI scanners and settings. Coupled with our semiautomated analysis pipeline, this protocol is key for the detailed morphometric characterization of compressed spinal cords in patients with DCM, a disease that is both complex and heterogenous. This study was funded by the National Institute of Neurological Disorders and Stroke (NINDS) (K23:NS091430) and (R01: NS129852-01A1)., Competing Interests: Declaration of competing interest One or more of the authors declare financial or professional relationships on ICMJE-TSJ disclosure forms., (Copyright © 2024 Elsevier Inc. All rights reserved.)
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- 2024
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11. Tract-specific magnetization transfer ratio provides insights into the severity of degenerative cervical myelopathy.
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Haynes G, Muhammad F, Weber KA 2nd, Khan AF, Hameed S, Shakir H, Van Hal M, Dickson D, Rohan M, Dhaher Y, Parrish T, Ding L, and Smith ZA
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Study Design: Cross-sectional study., Objectives: This study's goal is to report whether Magnetization Transfer Ratio (MTR) can evaluate the severity of white matter (WM) injury in degenerative cervical myelopathy (DCM)., Setting: Laureate Institute of Brain Research, USA; Department of Neurosurgery, University of Oklahoma Health Sciences Center, USA., Methods: 27 DCM patients were aged-matched with 20 healthy controls (HC) and categorized into treatment groups based on modified Japanese Orthopedic Association (mJOA) severity (11 mild and 16 moderate/severe). Regional and tract MTRs were extracted from the two vertebral levels containing maximum compression within magnetization transfer images. MTR differences between groups were assessed using a one-way ANOVA or Kruskal-Wallis test. The association between MTR and mJOA measures was evaluated using Spearman's correlation., Results: Significant decreases in MTR were found between HC and moderate/severe groups in the overall (p = 0.0065) and ventral (p = 0.0009) WM regions; and ventral corticospinal (p = 0.0101), ventral reticulospinal (p = 0.0084), spinal lemniscus (p = 0.0079), and fasciculus cuneatus (p = 0.0219) tracts. The spinal lemniscus MTR also significantly decreased between HC and mild groups (p = 0.038). Ventral reticulospinal tract MTR correlated with upper (r = 0.439; p = 0.022) and lower (r = 0.386; p = 0.047) limb motor mJOA scores., Conclusions: Significant tract-based MTR changes and correlations align with known DCM symptoms, are demonstrated to be lost at the regional level, and display the inhomogeneous compressive damage occurring within DCM spinal cords., (© 2024. The Author(s), under exclusive licence to International Spinal Cord Society.)
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- 2024
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12. Clinical phenotypes of DCM and their implications in post-surgery recovery.
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Muhammad F and Smith ZA
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Competing Interests: Declaration of interests We declare no competing interests.
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- 2024
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13. Evaluating osteoporosis and bone quality in the aging spine: modern considerations for surgical management in the geriatric population.
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Hudson M, Meyer J, Evans A, Krishna C, Smith ZA, and Bakhsheshian J
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- Humans, Aged, Spine surgery, Aging physiology, Risk Factors, Osteoporosis surgery, Bone Density
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Surgical management paradigms of spinal pathologies in the aging population carry inherent substantial risks, with surgical complications being more prevalent among patients with osteoporosis compared to those with normal bone mineral density. In this narrative review, we aim to highlight important clinical understanding and considerations in perioperative evaluation and management of patients elected to undergo spinal surgery. Osteoporosis is a well-defined risk factor for mechanical complications following spinal surgery, and as such, perioperative optimization of bone health in the setting of surgery for geriatric patients remains a critical research area alongside intraoperative surgical augmentation techniques. Surgical techniques to circumvent challenges with instrumentation of poor bone mineral density have included augmentation of pedicle screw fixation, including segmental bicortical screw fixation techniques, cement augmentation with fenestrated screws, or use of expandable pedicle screws to improve bone-implant interface. Judicious selection of treatment modalities and subsequent perioperative optimization is paramount to minimize surgical complications. Contemporary guidelines and evolving paradigms in perioperative evaluation, optimization, and management of the aging spine include the advent of quantitatively evaluating computed tomography (CT) via assessment of the magnitude of Hounsfield units. Prescribing pharmacotherapeutic agents and monitoring bone health requires a multidisciplinary team approach, including endocrinologists and geriatricians to coordinate high-quality care for advanced-age patients who require surgical management of their spinal disorders., (© 2024. The Author(s), under exclusive licence to American Aging Association.)
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- 2024
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14. Patterns of cortical thickness alterations in degenerative cervical myelopathy: associations with dexterity and gait dysfunctions.
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Muhammad F, Weber KA 2nd, Rohan M, and Smith ZA
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Degenerative cervical myelopathy (DCM) can lead to significant brain structural reorganization. The association between the cortical changes and specific motor symptoms in DCM has yet to be fully elucidated. We investigated the associations between cortical thickness changes with neurological symptoms, such as dexterity and gait abnormalities, in patients with DCM in a case-control study. A 3 Tesla MRI scanner was used to acquire high-resolution T1-weighted structural scans from 30 right-handed patients with DCM and 22 age-matched healthy controls. Pronounced cortical thinning was observed in DCM patients relative to healthy controls, particularly in the bilateral precentral and prefrontal gyri, left pars triangularis, left postcentral gyrus, right transverse temporal and visual cortices ( P ≤ 0.04). Notably, cortical thickness in these regions showed strong correlations with objective motor deficits ( P < 0.0001). Specifically, the prefrontal cortex, premotor area and supplementary motor area exhibited significant thickness reductions correlating with diminished dexterity (R
2 = 0.33, P < 0.0007; R2 = 0.34, P = 0.005, respectively). Similarly, declines in gait function were associated with reduced cortical thickness in the visual motor and frontal eye field cortices (R2 = 0.39, P = 0.029, R2 = 0.33, P = 0.04, respectively). Interestingly, only the contralateral precuneus thickness was associated with the overall modified Japanese Orthopaedic Association (mJOA) scores (R2 = 0.29, P = 0.003). However, the upper extremity subscore of mJOA indicated an association with the visual cortex and the anterior prefrontal (R2 = 0.48, P = 0.002, R2 = 0.33, P = 0.0034, respectively). In conclusion, our findings reveal patterns of cortical changes correlating with motor deficits, highlighting the significance of combining objective clinical and brain imaging assessments for understanding motor network dysfunction in DCM., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Guarantors of Brain.)- Published
- 2024
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15. Sarcopenia and the management of spinal disease in the elderly.
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Evans AR, Smith L, Bakhsheshian J, Anderson DB, Elliott JM, Shakir HJ, and Smith ZA
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Sarcopenia, generally defined by the loss of skeletal mass and function, may disproportionately affect elderly individuals and heavily influence spinal disease. Muscle atrophy is associated with myriad clinical problems, including thoracic kyphosis, increased sagittal vertical axis (SVA), spinal implant failures, and postoperative complications. As such, the aim of this narrative review is to synthesize pertinent literature detailing the intersection between sarcopenia and the impact of sarcopenia on the management of spine disease. Specifically, we focus on the domains of etiology, diagnosis and assessment, impact on the cervical and lumbar spine, spinal augmentation procedures, neoplastic disease, whiplash injury, and recovery/prevention. A narrative review was conducted by searching the PubMed and Google Scholar databases from inception to July 12, 2024, for any cohort studies, systematic reviews, or randomized controlled trials. Case studies and conference abstracts were excluded. Diagnosis of sarcopenia relies on the assessment of muscle strength and quantity/quality. Strength may be assessed using clinical tools such as gait speed, timed up and go (TUG) test, or hand grip strength, whereas muscle quantity/quality may be assessed via computed tomography (CT scan), magnetic resonance imaging (MRI), and dual-energy X-ray absorptiometry (DXA scan). Sarcopenia has a generally negative impact on the clinical course of those undergoing cervical and lumbar surgery, and may be predictive of mortality in those with neoplastic spinal disease. In addition, severe acceleration-deceleration (whiplash) injuries may result in cervical extensor muscle atrophy. Intervention and recovery measures include nutrition or exercise therapy, although the evidence for nutritional intervention is lacking. Sarcopenia is a widely prevalent pathology in the advanced-age population, in which the diagnostic criteria, impact on spinal pathology, and recovery/prevention measures remain understudied. However, further understanding of this therapeutically challenging pathology is paramount, as surgical outcome may be heavily influenced by sarcopenia status., (© 2024. The Author(s), under exclusive licence to American Aging Association.)
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- 2024
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16. What is normal age-related thigh muscle composition among 45- to 84-year-old adults from the UK Biobank study.
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Anderson DB, Beach AJ, Chen L, Feng HJ, McKay MJ, Smith ZA, Weber KA 2nd, Wesselink EO, and Elliott JM
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A loss of skeletal muscle mass and an increase in intramuscular fat are known to occur as we enter middle and older age, but the expected changes or normative values have remained unknown. The primary reason for this is that imaging studies are difficult and expensive to conduct, and consequently, the sample sizes have remained small. The development of the UK Biobank which provides access to a large magnetic resonance imaging (MRI) data set of more than 50,000 participants provides an opportunity to finally address this question of normative values for each age group. The study's primary aim was to determine the age-related changes in thigh muscle composition (e.g., thigh fat-free muscle volume and intramuscular fat) between the ages of 45 and 84 years. The second aim was to analyse associations between thigh fat-free muscle volume and intramuscular fat with lifestyle behaviours (smoking, alcohol consumption, and physical activity), leg pain, and bone mineral density. Fifty thousand three hundred thirty-two participants were included in the study. Total fat-free thigh muscle declined between the ages of 45 and 84 years, while intramuscular fat of the thigh continued to increase. The changes were stable between these age groups. The mean volume of fat-free muscle ranged from 11.16 (SD: 1.40) to 13.26 L (SD: 1.85) in adult males and 7.60 (SD: 0.97) to 8.80 L (SD 1.29) in females between the ages of 45 and 84 years. For intramuscular fat, the change among women was from 6.94% (SD: 1.59) in the 45 to 54 years age bracket to 8.83% (SD: 1.92) in the 75 to 84 age bracket, while for men, it was 5.83% (SD: 1.30) in the 45 to 54 age bracket to 7.85% (SD 1.89) in the 75 to 84 age bracket. The total fat-free muscle volume and intramuscular fat percentage provided can be used for the purpose of reference standards or normative values for adults in the age groups provided. Fat-free muscle and intramuscular fat were found to be associated with a range of health, activity, and leg pain outcomes, and these should be investigated in a follow-up longitudinal imaging study., (© 2024. The Author(s).)
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- 2024
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17. Distinct Time-Resolved Brain-Wide Coactivations in Oxygenated and Deoxygenated Hemoglobin.
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Khan AF, Yuan H, Smith ZA, and Ding L
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- Adult, Female, Humans, Male, Young Adult, Brain Mapping methods, Oxyhemoglobins analysis, Oxyhemoglobins metabolism, Spectroscopy, Near-Infrared methods, Tomography, Optical methods, Brain diagnostic imaging, Brain metabolism, Brain physiology, Hemoglobins metabolism, Hemoglobins analysis
- Abstract
Objective: Human resting-state networks (RSNs) estimated from oxygenated (HbO) and deoxygenated hemoglobin (HbR) data exhibit strong similarities, while task-based studies show different dynamics in HbR and HbO responses. Such a discrepancy might be explained due to time-averaged estimations of RSNs. Our study investigated differences between HbO and HbR on time-resolved brain-wide coactivation patterns (CAPs)., Methods: Diffuse optical tomography was reconstructed from resting-state whole-head functional near-infrared spectroscopy data of HbR and HbO in individual healthy participants. Time-averaged RSNs were obtained using the group-level independent component analysis. Time-resolved CAPs were estimated using a clustering approach on the time courses of all obtained RSNs. Characteristics of the RSNs and CAPs from HbR and HbO were compared., Results: Spatial patterns of HbR and HbO RSNs exhibited significant similarities. Meanwhile, HbR CAPs revealed much more organized spatial and dynamic characteristics than HbO CAPs. The entire set of HbR CAPs suggests a superstructure resulted from brain-wide neuronal dynamics, which is less evident in the set of HbO CAPs. These differences between HbO and HbR CAPs were consistently replicated in individual session data., Conclusion: Our results suggest that human resting brain-wide neuronal activations are preserved better in time-resolved brain-wide patterns, i.e., CAPs, from HbR than those from HbO, while such a difference is lost between time-averaged HbR and HbO RSNs., Significance: Our results reveal, for the first time, HbR concentration fluctuations are more directly coupled with resting dynamics of brain-wide neuronal activations in human brains.
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- 2024
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18. Neurovascular coupling, functional connectivity, and cerebrovascular endothelial extracellular vesicles as biomarkers of mild cognitive impairment.
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Owens CD, Pinto CB, Mukli P, Gulej R, Velez FS, Detwiler S, Olay L, Hoffmeister JR, Szarvas Z, Muranyi M, Peterfi A, Pinaffi-Langley ACDC, Adams C, Sharps J, Kaposzta Z, Prodan CI, Kirkpatrick AC, Tarantini S, Csiszar A, Ungvari Z, Olson AL, Li G, Balasubramanian P, Galvan V, Bauer A, Smith ZA, Dasari TW, Whitehead S, Medapti MR, Elahi FM, Thanou A, and Yabluchanskiy A
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- Humans, Female, Male, Aged, Magnetic Resonance Imaging, Spectroscopy, Near-Infrared, Middle Aged, Cognitive Dysfunction physiopathology, Extracellular Vesicles metabolism, Biomarkers blood, Neurovascular Coupling physiology
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Introduction: Mild cognitive impairment (MCI) is a prodromal stage of dementia. Understanding the mechanistic changes from healthy aging to MCI is critical for comprehending disease progression and enabling preventative intervention., Methods: Patients with MCI and age-matched controls (CN) were administered cognitive tasks during functional near-infrared spectroscopy (fNIRS) recording, and changes in plasma levels of extracellular vesicles (EVs) were assessed using small-particle flow cytometry., Results: Neurovascular coupling (NVC) and functional connectivity (FC) were decreased in MCI compared to CN, prominently in the left-dorsolateral prefrontal cortex (LDLPFC). We observed an increased ratio of cerebrovascular endothelial EVs (CEEVs) to total endothelial EVs in patients with MCI compared to CN, correlating with structural MRI small vessel ischemic damage in MCI. LDLPFC NVC, CEEV ratio, and LDLPFC FC had the highest feature importance in the random Forest group classification., Discussion: NVC, CEEVs, and FC predict MCI diagnosis, indicating their potential as markers for MCI cerebrovascular pathology., Highlights: Neurovascular coupling (NVC) is impaired in mild cognitive impairment (MCI). Functional connectivity (FC) compensation mechanism is lost in MCI. Cerebrovascular endothelial extracellular vesicles (CEEVs) are increased in MCI. CEEV load strongly associates with cerebral small vessel ischemic lesions in MCI. NVC, CEEVs, and FC predict MCI diagnosis over demographic and comorbidity factors., (© 2024 The Author(s). Alzheimer's & Dementia published by Wiley Periodicals LLC on behalf of Alzheimer's Association.)
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- 2024
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19. Surgical management of spinal pathologies in the octogenarian: a narrative review.
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Evans AR, Bakhsheshian J, Graffeo CS, and Smith ZA
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- Humans, Aged, 80 and over, Spinal Fractures surgery, Odontoid Process surgery, Odontoid Process diagnostic imaging, Odontoid Process injuries, Spinal Diseases surgery, Spinal Diseases diagnostic imaging, Decompression, Surgical methods, Spinal Fusion methods
- Abstract
Optimal management paradigms of spinal pathologies in the octogenarian population are controversial given the higher incidence of comorbidities with concern for poor prognosis and fear of increased complications associated with surgical management. In this narrative review, we aim to detail the complex clinical considerations when approaching odontoid screw fixation/instrumented fusion, spinal decompression, and spinal fusion in the octogenarian. Literature review was conducted via Google Scholar and PubMed databases, with literature selected based on statistical power and clinical relevance to the following pathologies/surgical techniques: odontoid fracture, surgical decompression, and surgical fusion in the octogenarian. The aforementioned pathologies were selected based on prevalence in the advanced-age population in which surgical screening techniques and management remain nonuniform. Preoperative evaluation of the octogenarian patient increasingly includes frailty, sarcopenia, and osteopenia/osteoporosis assessments. In cases of odontoid fracture, conservative management appears to provide beneficial clinical outcomes with lower rates of complication compared to surgery; however, rates of radiographic odontoid fusion are far lower in conservatively managed patients. Regarding surgical decompression and fusion, the presence of comorbidities may be more predictive of outcome rather than age status, with the advent of minimally invasive techniques providing safety and efficacy in the surgical management of this age cohort. Age status may be less pertinent than previously thought in the decision to pursue spinal surgery for odontoid fracture, spinal decompression, or spinal fusion; however, each of these procedures has respective risks and benefits that must be considered within the context of each patient's comorbidity profile., (© 2024. The Author(s), under exclusive licence to American Aging Association.)
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- 2024
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20. Early neurological changes in aging cervical spine: insights from PROMIS mobility assessment.
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Hameed S, Muhammad F, Haynes G, Smith L, Khan AF, and Smith ZA
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- Humans, Cervical Vertebrae diagnostic imaging, Patient Reported Outcome Measures, Aging, Spinal Cord Compression, Spinal Cord Diseases diagnostic imaging, Spinal Cord Diseases epidemiology
- Abstract
Many studies have shown that the prevalence of degenerative spinal cord compression increases with age. However, most cases at early stages are asymptomatic, and their diagnosis remains challenging. Asymptomatic cervical spinal cord compression (ASCC) patients are more likely to experience annular tears, herniated disks, and later develop symptomatic compression. Asymptomatic individuals do not typically undergo spinal cord imaging; therefore, an assessment test that is both sensitive and specific in diagnosing ASCC may be helpful. It has been demonstrated that the Patient Reported Outcome Measure Information System (PROMIS) mobility test is sensitive in detecting degenerative cervical myelopathy (DCM) symptoms. We investigated the use of the PROMIS mobility test in assessing clinical dysfunction in ASCC. In this study, 51 DCM patients and 42 age-matched healthy control (HC) were enrolled. The degree of cervical spinal cord compression was assessed using the high-resolution cervical spinal cord T2 Weighted (T2w) MRIs, which were available for 14 DCM patients. Measurements of the spinal cords anterior-posterior (AP) diameter at the region(s) that were visibly compressed as well as at different cervical spine levels were used to determine the degree of compression. The age-matched HC cohort had a similar MRI to establish the normal range for AP diameter. Twelve (12) participants in the HC cohort had MRI evidence of cervical spinal cord compression; these individuals were designated as the ASCC cohort. All participants completed the PROMIS mobility, PROMIS pain interference (PI), PROMIS upper extremity (UE), modified Japanese orthopedic association (mJOA), and neck disability index (NDI) scoring scales. We examined the correlation between the AP diameter measurements and the clinical assessment scores to determine their usefulness in the diagnosis of ASCC. Furthermore, we examine the sensitivity and specificity of PROMIS mobility test and mJOA. Compared to the HC group, the participants in the ASCC and DCM cohorts were significantly older (p = 0.006 and p < 0.0001, respectively). Age differences were not observed between ASCC and DCM (p > 0.999). Clinical scores between the ASCC and the HC group were not significantly different using the mJOA (p > 0.99), NDI (p > 0.99), PROMIS UE (p = 0.23), and PROMIS PI (p = 0.82). However, there were significant differences between the ASCC and HC in the PROMIS mobility score (p = 0.01). The spinal cord AP diameter and the PROMIS mobility score showed a significant correlation (r = 0.44, p = 0.002). Decreasing PROMIS mobility was significantly associated with a decrease in cervical spinal cord AP diameter independent of other assessment measures. PROMIS mobility score had a sensitivity of 77.3% and specificity of 79.4% compared to 59.1% and 88.2%, respectively, for mJOA in detecting cervical spinal cord compression. Certain elements of ASCC are not adequately captured with the traditional mJOA and NDI scales used in DCM evaluation. In contrast to other evaluation scales utilized in this investigation, PROMIS mobility score shows a significant association with the AP diameter of the cervical spinal cord, suggesting that it is a sensitive tool for identifying early disability associated with degenerative change in the aging spine. In a comparative analysis of PROMIS mobility test against the standard mJOA, the PROMIS mobility demonstrated higher sensitivity for detecting cervical spinal cord compression. These findings underscore the potential use of PROMIS mobility score in clinical evaluation of the aging spine., (© 2024. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)
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- 2024
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21. Body size interacts with the structure of the central nervous system: A multi-center in vivo neuroimaging study.
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Labounek R, Bondy MT, Paulson AL, Bédard S, Abramovic M, Alonso-Ortiz E, Atcheson NT, Barlow LR, Barry RL, Barth M, Battiston M, Büchel C, Budde MD, Callot V, Combes A, De Leener B, Descoteaux M, de Sousa PL, Dostál M, Doyon J, Dvorak AV, Eippert F, Epperson KR, Epperson KS, Freund P, Finsterbusch J, Foias A, Fratini M, Fukunaga I, Gandini Wheeler-Kingshott CAM, Germani G, Gilbert G, Giove F, Grussu F, Hagiwara A, Henry PG, Horák T, Hori M, Joers JM, Kamiya K, Karbasforoushan H, Keřkovský M, Khatibi A, Kim JW, Kinany N, Kitzler H, Kolind S, Kong Y, Kudlička P, Kuntke P, Kurniawan ND, Kusmia S, Laganà MM, Laule C, Law CSW, Leutritz T, Liu Y, Llufriu S, Mackey S, Martin AR, Martinez-Heras E, Mattera L, O'Grady KP, Papinutto N, Papp D, Pareto D, Parrish TB, Pichiecchio A, Prados F, Rovira À, Ruitenberg MJ, Samson RS, Savini G, Seif M, Seifert AC, Smith AK, Smith SA, Smith ZA, Solana E, Suzuki Y, Tackley GW, Tinnermann A, Valošek J, Van De Ville D, Yiannakas MC, Weber KA 2nd, Weiskopf N, Wise RG, Wyss PO, Xu J, Cohen-Adad J, Lenglet C, and Nestrašil I
- Abstract
Clinical research emphasizes the implementation of rigorous and reproducible study designs that rely on between-group matching or controlling for sources of biological variation such as subject's sex and age. However, corrections for body size (i.e. height and weight) are mostly lacking in clinical neuroimaging designs. This study investigates the importance of body size parameters in their relationship with spinal cord (SC) and brain magnetic resonance imaging (MRI) metrics. Data were derived from a cosmopolitan population of 267 healthy human adults (age 30.1±6.6 years old, 125 females). We show that body height correlated strongly or moderately with brain gray matter (GM) volume, cortical GM volume, total cerebellar volume, brainstem volume, and cross-sectional area (CSA) of cervical SC white matter (CSA-WM; 0.44≤r≤0.62). In comparison, age correlated weakly with cortical GM volume, precentral GM volume, and cortical thickness (-0.21≥r≥-0.27). Body weight correlated weakly with magnetization transfer ratio in the SC WM, dorsal columns, and lateral corticospinal tracts (-0.20≥r≥-0.23). Body weight further correlated weakly with the mean diffusivity derived from diffusion tensor imaging (DTI) in SC WM (r=-0.20) and dorsal columns (-0.21), but only in males. CSA-WM correlated strongly or moderately with brain volumes (0.39≤r≤0.64), and weakly with precentral gyrus thickness and DTI-based fractional anisotropy in SC dorsal columns and SC lateral corticospinal tracts (-0.22≥r≥-0.25). Linear mixture of sex and age explained 26±10% of data variance in brain volumetry and SC CSA. The amount of explained variance increased at 33±11% when body height was added into the mixture model. Age itself explained only 2±2% of such variance. In conclusion, body size is a significant biological variable. Along with sex and age, body size should therefore be included as a mandatory variable in the design of clinical neuroimaging studies examining SC and brain structure., Competing Interests: Declaration of interests Since June 2022, Dr. A.K. Smith has been employed by GE HealthCare. This article was co-authored by Dr. Smith in his personal capacity. The opinions expressed in the article are his in and do not necessarily reflect the views of GE HealthCare. Since August 2022, Dr. M. M. Laganà has been employed by Canon Medical Systems srl, Rome, Italy. This article was co-authored by Dr. M. M. Laganà in her personal capacity. The opinions expressed in the article are her own and do not necessarily reflect the views of Canon Medical Systems. Since September 2023, Dr. Papp has been an employee of Siemens Healthcare AB, Sweden. This article was co-authored by Dr. Papp in his personal capacity. The views and opinions expressed in this article are his own and do not necessarily reflect the views of Siemens Healthcare AB, or Siemens Healthineers AG. Since January 2024, Dr. Barry has been employed by the National Institute of Biomedical Imaging and Bioengineering at the NIH. This article was co-authored by Robert Barry in his personal capacity. The opinions expressed in the article are his own and do not necessarily reflect the views of the NIH, the Department of Health and Human Services, or the United States government. Guillaume Gilbert is an employee of Philips Healthcare. S Llufriu received compensation for consulting services and speaker honoraria from Biogen Idec, Novartis, Bristol Myer Squibb Genzyme, Sanofi Jansen and Merck. The Max Planck Institute for Human Cognitive and Brain Sciences and Wellcome Centre for Human Neuroimaging have institutional research agreements with Siemens Healthcare. NW holds a patent on acquisition of MRI data during spoiler gradients (US 10,401,453 B2). NW was a speaker at an event organized by Siemens Healthcare and was reimbursed for the travel expenses. The other authors declare no competing interests.
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- 2024
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22. Degenerative cervical myelopathy: establishing severity thresholds for neuromotor dysfunction in the aging spine using the NIH Toolbox Assessment Scale.
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Muhammad F, Hameed S, Haynes G, Mohammadi E, Khan AF, Shakir H, and Smith ZA
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- Humans, Aging, Case-Control Studies, Cervical Vertebrae, Pilot Projects, Spinal Cord Diseases diagnosis
- Abstract
Degenerative cervical myelopathy (DCM) is a leading cause of age-related non-traumatic spinal cord disorders resulting from chronic degeneration of the cervical spine. While traditional clinical assessments rely on patient-reported measures, this study used the NIH Toolbox Motor Battery (NIHTBm) as an objective, quantitative measure to determine DCM severity. The objective is to define NIHTBm cutoff values that can accurately classify the severity of DCM neuromotor dysfunction. A case-controlled pilot study of patients with DCM and age-matched controls. The focus was an in-depth quantitative motor assessment using the NIHTBm to understand the severity of neuromotor deficits due to degenerative spine disease. Motor assessments, dexterity, grip strength, balance, and gait speed were measured in 45 DCM patients and 37 age-matched healthy subjects (HC). Receiver operating curve (ROC) analysis determined cutoff values for mild and moderate-to-severe myelopathy which were validated by comparing motor assessment scores with disability scores. The ROC curves identified thresholds for mild dexterity impairment (T-score range 38.4 - 33.5, AUC 0.77), moderate-to-severe dexterity impairment (< 33.5, AUC 0.70), mild grip strength impairment (47.4 - 32.0, AUC 0.80), moderate-to-severe grip strength impairment (< 32.0, AUC 0.75), mild balance impairment (36.4 - 33.0, AUC 0.61), and moderate-to-severe balance impairment (< 33.0, AUC 0.78). Mild gait speed impairment was defined as 0.78-0.6 m/sec (AUC 0.65), while moderate-to-severe gait speed impairment was < 0.6 m/sec (AUC 0.65). The NIHTB motor score cutoff points correlated negatively with the DCM neck disability index (NDI) and showed balance and dexterity measures as independent indicators of DCM dysfunction. The use of NIHTB allows for precise delineation of DCM severity by establishing cutoff values corresponding to mild and moderate-to-severe myelopathy. The use of NIHTB in DCM allows enhanced clinical precision, enabling clinicians to better pinpoint specific motor deficits in DCM and other neurological disorders with motor deficits, including stroke and traumatic brain injury (TBI). Furthermore, the utility of objective assessment, NIHTB, allows us to gain a better understanding of the heterogeneity of DCM, which will enhance treatment strategies. This study serves as a foundation for future research to facilitate the discovery of innovative treatment strategies for DCM and other neurological conditions., (© 2023. The Author(s), under exclusive licence to American Aging Association.)
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- 2024
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23. Beyond the aging spine - a systematic review of functional changes in the human brain in cervical spondylotic myelopathy.
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Khan AF, Muhammad F, Mohammadi E, O'Neal C, Haynes G, Hameed S, Walker B, Rohan ML, Yabluchanskiy A, and Smith ZA
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- Humans, Aged, Cervical Vertebrae diagnostic imaging, Brain diagnostic imaging, Aging, Spondylosis diagnostic imaging, Spinal Cord Diseases
- Abstract
Cervical Spondylotic Myelopathy (CSM) is a degenerative condition that leads to loss of cervical spinal cord integrity, typically affecting the aged population. Emerging fMRI-based evidence suggests that the brain is also affected by CSM. This systematic review aimed to understand the usefulness of brain fMRI in CSM. A comprehensive literature search was conducted until March 2023 according to PRISMA guidelines. The inclusion criteria included original research articles in English, primarily studying the human brain's functional changes in CSM using fMRI with at least 5 participants. The extracted data from each study included demographics, disease severity, MRI machine characteristics, affected brain areas, functional changes, and clinical utilities. A total of 30 studies met the inclusion criteria. Among the fMRI methods, resting-state fMRI was the most widely used experimental paradigm, followed by motor tasks. The brain areas associated with motor control were most affected in CSM, followed by the superior frontal gyrus and occipital cortex. Functional changes in the brain were correlated to clinical metrics showing clinical utility. However, the evidence that a specific fMRI metric correlating with a clinical metric was "very low" to "insufficient" due to a low number of studies and negative results. In conclusion, fMRI can potentially facilitate the diagnosis of CSM by quantitatively interrogating the functional changes of the brain, particularly areas of the brain associated with motor control. However, this field is in its early stages, and more studies are needed to establish the usefulness of brain fMRI in CSM., (© 2023. The Author(s), under exclusive licence to American Aging Association.)
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- 2024
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24. Letter: Learning Curves for Robot-Assisted Pedicle Screw Placement: Analysis of Operative Time for 234 Cases.
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Smith ZA, Muhammad F, and Baaj AA
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- Humans, Learning Curve, Operative Time, Robotics, Pedicle Screws, Robotic Surgical Procedures
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- 2024
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25. Post-pandemic paradigm shift toward telemedicine and tele-education; an updated survey of the impact of Covid-19 pandemic on neurosurgery residents in United States.
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Mohammadi E, Smith L, Khan AF, Lee B, Spencer O, Muhammad F, Villeneuve LM, Dunn IF, and Smith ZA
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Background: Several strategies were implemented during the Covid-19 pandemic to enhance residency training and patient care., Objective: This study aims to assess the post-pandemic landscape of neurosurgical training and practice., Method: A survey consisting of 28 questions examining the challenges faced in neurosurgery and the adaptive measures was conducted among US neurosurgery residents from May 2022 to May 2023., Results: This study encompassed 59 neurosurgical residents, predominantly male (72.9%) and in later years of training (66.1%) and were distributed across 25 states. Telemedicine and tele-education were pivotal during the pandemic, with virtual lecture series, standalone lectures, and virtual discussions highly favored. Remote didactic learning increased for nearly half of the residents, while 54.2% resumed in-person instruction. Telemedicine was deemed effective by 86.4% for evaluating neurosurgical patients. Access to teaching environments was restricted for 61.0% of residents, impacting their training. The pandemic significantly influenced elective surgeries, with complete cancellations reported by 42.4%. Reduced faculty engagement was noted by 35.6% of residents, while 47.5% reported a negative impact on the overall resident experience. The majority (76.3%) considered changes to their training reasonable given the global health situation., Conclusions: Strategies implemented during the peak of the pandemic remain crucial in shaping neurosurgery training. Telemedicine has become indispensable, with widespread adoption. Tele-education has also expanded, providing additional learning opportunities. However, traditional didactic courses and hands-on experiences remain essential for comprehensive training. Balancing technology-driven methods with established approaches is crucial for optimizing neurosurgical education and maintaining high-quality patient care., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)
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- 2024
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26. Systematic review protocol for complications following surgical decompression of degenerative cervical myelopathy.
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Mohammadi E, Khan AF, Villeneuve LM, Hameed S, Haynes G, Muhammad F, and Smith ZA
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- Adult, Humans, Adolescent, Retrospective Studies, Prospective Studies, Systematic Reviews as Topic, Decompression, Surgical adverse effects, Decompression, Surgical methods, Cervical Vertebrae surgery, Spinal Cord Diseases etiology, Spinal Cord Diseases surgery
- Abstract
Background: Degenerative Cervical Myelopathy (DCM) is one of the most common degenerative disorders of cervical spine and sources of cord dysfunction in adults. It usually manifests with neurologic presentations such as loss of dexterity and gait issues. Treatment for moderate and severe cases of DCM is surgical decompression of the region. There are many approaches available for surgical intervention which could be categorized into anterior and posterior based on the side of neck where operation takes place. Additionally, for certain cases the hybridized anterior-posterior combined surgery is indicated. While there are many technical differences between these approaches with each having its own advantages, the complications and safety profiles of them are not fully disclosed. This protocol aims to systematically search for current reports on complications of surgical decompression methods of DCM and pool them for robust evidence generation., Method: Search will be carried out in PubMed, Scopus, and Cochrane databases for retrospective and prospective surgical series, cohorts, or trials being performed for DCM with at least a sample size of 20 patients. Query strings will be designed to capture reports with details of complications with no year limit. Studies not being original (e.g., review articles, case reports, etc.), not in English, having patients younger than 18-years-old, and not reporting at least one complication will be excluded. Two independent reviewers will review the titles and abstracts for first round of screening. Full text of retrieved studies from previous round will be screened again by the same reviewers. In case of discrepancy, the third senior reviewer will be consulted. Eligible studies will then be examined for data extraction where data will be recorded into standardized form. Cumulative incidence and 95% confidence intervals of complication will be then pooled based on generalized linear mixed models with consideration of approach of surgery as subgroups. Heterogeneity tests will be performed for assessment of risk of bias., Discussion: This systematic review is aimed at providing practical information for spine surgeons on the rates of complications of different surgical approaches of DCM decompression. Proper decision-making regarding the surgical approach in addition to informing patients could be facilitated through results of this investigation., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Mohammadi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)
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- 2024
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27. Evaluating tissue injury in cervical spondylotic myelopathy with spinal cord MRI: a systematic review.
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Khan AF, Mohammadi E, Haynes G, Hameed S, Rohan M, Anderson DB, Weber KA 2nd, Muhammad F, and Smith ZA
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- Humans, Diffusion Tensor Imaging methods, Spinal Cord pathology, Magnetic Resonance Imaging, Cervical Vertebrae diagnostic imaging, Cervical Vertebrae pathology, Biomarkers, Spinal Cord Diseases diagnostic imaging, Spinal Cord Diseases etiology, Spinal Cord Diseases pathology, Spondylosis complications, Spondylosis diagnostic imaging, Spondylosis pathology
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Purpose: Cervical Spondylotic Myelopathy (CSM) is a degenerative condition that leads to loss of cervical spinal cord (CSC) integrity. Various spinal cord Magnetic Resonance Imaging (MRI) methods can identify and characterize the extent of this damage. This systematic review aimed to evaluate the diagnostic, biomarker, and predictive utilities of different spinal cord MRI methods in clinical research studies of CSM. The aim was to provide a comprehensive understanding of the progress in this direction for future studies and effective diagnosis and management of CSM., Methods: A comprehensive literature search was conducted on PubMed and EMBASE from 2010 to 2022 according to PRISMA guidelines. Studies with non-human subjects, less than 3T magnetic field strength, non-clinical design, or not quantitatively focusing on the structural integrity of CSC were excluded. The extracted data from each study included demographics, disease severity, MRI machine characteristics, quantitative metrics, and key findings in terms of diagnostic, biomarker, and predictive utilities of each MRI method. The risk of bias was performed using the guide from AHRQ. The quality of evidence was assessed separately for each type of utility for different MRI methods using GRADE., Results: Forty-seven studies met the inclusion criteria, utilizing diffusion-weighted imaging (DTI) (n = 39), magnetization transfer (MT) (n = 6), MR spectroscopy (n = 3), and myelin water imaging (n = 1), as well as a combination of MRI methods (n = 12). The metric fractional anisotropy (FA) showed the highest potential in all facets of utilities, followed by mean diffusivity. Other promising metrics included MT ratio and intracellular volume fraction, especially in multimodal studies. However, the level of evidence for these promising metrics was low due to a small number of studies. Some studies, mainly DTI, also reported the usefulness of spinal cord MRI in mild CSM., Conclusions: Spinal cord MRI methods can potentially facilitate the diagnosis and management of CSM by quantitatively interrogating the structural integrity of CSC. DTI is the most promising MRI method, and other techniques have also shown promise, especially in multimodal configurations. However, this field is in its early stages, and more studies are needed to establish the usefulness of spinal cord MRI in CSM., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
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- 2024
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28. A Diagnostic Biomarker for Cervical Myelopathy Based on Dynamic Magnetic Resonance Imaging.
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Muhammad F and Smith ZA
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- Humans, Magnetic Resonance Imaging methods, Biomarkers, Cervical Vertebrae diagnostic imaging, Spinal Cord Diseases diagnostic imaging, Spinal Cord Compression diagnosis
- Abstract
Competing Interests: The authors report no conflicts of interest.
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- 2023
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29. Spinal Cord Injury: The Global Incidence, Prevalence, and Disability From the Global Burden of Disease Study 2019.
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Mohammadi E, Villeneuve LM, and Smith ZA
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- Humans, Prevalence, Incidence, Global Burden of Disease, Global Health, Quality-Adjusted Life Years, Spinal Cord Injuries epidemiology, Disabled Persons
- Abstract
Competing Interests: The authors report no conflicts of interest.
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- 2023
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30. The current state of spinal cord functional magnetic resonance imaging and its application in clinical research.
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Haynes G, Muhammad F, Khan AF, Mohammadi E, Smith ZA, and Ding L
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- Humans, Spinal Cord pathology, Magnetic Resonance Imaging methods, Cervical Vertebrae, Spinal Cord Injuries diagnostic imaging, Spinal Cord Diseases diagnostic imaging, Spinal Cord Diseases pathology
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Since its development, spinal cord functional magnetic resonance imaging (fMRI) has utilized various methodologies and stimulation protocols to develop a deeper understanding of a healthy human spinal cord that lays a foundation for its use in clinical research and practice. In this review, we conducted a comprehensive literature search on spinal cord fMRI studies and summarized the recent advancements and resulting scientific achievements of spinal cord fMRI in the following three aspects: the current state of spinal cord fMRI methodologies and stimulation protocols, knowledge about the healthy spinal cord's functions obtained via spinal cord fMRI, and fMRI's exemplary usage in spinal cord diseases and injuries. We conclude with a discussion that, while technical challenges exist, novel fMRI technologies for and new knowledge about the healthy human spinal cord have been established. Empowered by these developments, investigations of pathological and injury states within the spinal cord have become the next important direction of spinal cord fMRI. Recent clinical investigations into spinal cord pathologies, for example, fibromyalgia, multiple sclerosis, spinal cord injury, and cervical spondylotic myelopathy, have already provided deep insights into spinal cord impairments and the time course of impairment-caused changes. We expect that future spinal cord fMRI advancement and research development will further enhance our understanding of various spinal cord diseases and provide the foundation for evaluating existing and developing new treatment plans., (© 2023 American Society of Neuroimaging.)
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- 2023
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31. Letter to the Editor Regarding "The Potential Negative Effects of Smoking on Cervical and Lumbar Surgery Beyond Pseudarthrosis: A Michigan Spine Surgery Improvement Collaborative Study".
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Mohammadi E, Villeneuve LM, and Smith ZA
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- Humans, Smoking, Michigan, Tobacco Smoking, Treatment Outcome, Lumbar Vertebrae surgery, Retrospective Studies, Pseudarthrosis etiology, Pseudarthrosis surgery, Spinal Fusion adverse effects
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- 2023
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32. Letter to the Editor: Comparative Analysis of 30-Day Readmission, Reoperation, and Morbidity between Posterior Cervical Decompression and Fusion Performed in Inpatient and Outpatient Settings.
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Mohammadi E, Villeneuve L, and Smith ZA
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- 2023
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33. Utility of MRI in Quantifying Tissue Injury in Cervical Spondylotic Myelopathy.
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Khan AF, Haynes G, Mohammadi E, Muhammad F, Hameed S, and Smith ZA
- Abstract
Cervical spondylotic myelopathy (CSM) is a progressive disease that worsens over time if untreated. However, the rate of progression can vary among individuals and may be influenced by various factors, such as the age of the patients, underlying conditions, and the severity and location of the spinal cord compression. Early diagnosis and prompt treatment can help slow the progression of CSM and improve symptoms. There has been an increased use of magnetic resonance imaging (MRI) methods in diagnosing and managing CSM. MRI methods provide detailed images and quantitative structural and functional data of the cervical spinal cord and brain, allowing for an accurate evaluation of the extent and location of tissue injury. This review aims to provide an understanding of the use of MRI methods in interrogating functional and structural changes in the central nervous system in CSM. Further, we identified several challenges hindering the clinical utility of these neuroimaging methods.
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- 2023
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34. Isolating Neurologic Deficits in Cervical Spondylotic Myelopathy: A Case-Controlled Study, Using the NIH Toolbox Motor Battery.
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Muhammad F, Baha A, Haynes G, Shakir H, Omini M, Martin M, Weber KA 2nd, Paliwal M, Van Hal M, Dickson D, Dhaher Y, Zhao YD, and Smith ZA
- Abstract
Background and Objectives: Patients with cervical spondylotic myelopathy (CSM) have motor impairments, including weakness, imbalance, and loss of dexterity. The reliable assessment of these symptoms is critical for treatment decisions. This study aimed to determine, for the first time, the use of the NIH Toolbox motor battery (NIHTBm) in the objective assessment of motor deficits in patients with CSM., Methods: Patients with symptoms and MRI evidence of CSM and age-matched healthy controls (HC), with no evidence of spinal disorder or surgery were included in this case-control study based on our inclusion and exclusion criteria. We performed motor tests, dexterity, gait speed, grip strength, and balance tests, using the NIHTBm in patients with CSM and HCs. Motor impairment rates were determined in patients with CSM based on the NIHTBm scores. We determined the association between NIHTBm scores and patient-reported outcome scores; patient-reported outcome measures (the modified Japanese Orthopedic Association [mJOA] and Nurick grade) to determine the association. One-way analysis of variance was used to analyze group differences and the Spearman rank correlation to determine the relationship between assessment scores., Results: We enrolled 24 patients with CSM with a mean age (SD) of 57.96 (10.61) years and 24 age-matched HCs with a mean age (SD) of 53.17 (6.04) years in this study. Overall, we observed a significant decrease in the motor function T-scores mean (SD): dexterity 31.54 (14.82) vs 51.54 (9.72), grip strength 32.00 (17.47) vs 56.79 (8.46), balance 27.58 (16.65) vs 40.21 (6.35), and gait speed 0.64 (0.18) vs 0.99 (0.17) m/s, in patients with CSM compared with that in HCs. The lower extremity dysfunction scores on the NIHTBm, balance (ρ = -0.67) and gait speed (ρ = -0.62), were associated with higher Nurick grades. We observed a similar but weaker association with the Nurick grades and NIHTBm tests: dexterity (ρ = -0.49) and grip strength (ρ = -0.31) scores. The total motor mJOA showed a positive but weak association with NIHTBm scores, gait speed (ρ = 0.38), balance (ρ = 0.49), grip strength (ρ = 0.41), and dexterity (ρ = 0.45)., Discussion: Patients with CSM had significantly lower NIHTBm scores compared with HCs. The results from the NIHTBm are consistent with the clinical presentation of CSM showing patients have motor impairments in both upper and lower extremities. As a neurologic-specific scale, NIHTBm should be used in the evaluation and clinical management of patients with CSM., Competing Interests: F. Muhammad, A. Baha, G. Haynes, H. Shakir, M. Omini, and M. Martin report no disclosures relevant to the manuscript. K.A. Weber II received funding from the National Institute on Neurologic Disorders and Stroke (grant K23NS104211 and L30NS108301). M. Paliwal, M. Van Hal, and D. Dickson report no disclosures relevant to the manuscript. Y. Dhaher received funding from the National Institute of Arthritis and Musculoskeletal and Skin Diseases (grant R01 AR06976-03). Y.D. Zhao reports no disclosures relevant to the manuscript. Z.A. Smith is funded by NIH-NINDS K23 grant K23NS091430, Presbyterian Health Foundation Team Science Research, and Oklahoma Shared Clinical and Translational Research (OSCTR) NIH-IDeA grant. Full disclosure form information provided by the authors is available with the full text of this article at Neurology.org/cp., (Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.)
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- 2023
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35. Importance of valid, reliable, and responsive outcome measures for lumbar spinal stenosis.
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Anderson DB, Mobbs RJ, Smith ZA, De Luca K, Sabet T, and Van Gelder JM
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- Humans, Treatment Outcome, Outcome Assessment, Health Care, Reproducibility of Results, Lumbar Vertebrae surgery, Spinal Stenosis surgery
- Abstract
Competing Interests: Declarations of Competing Interests The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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- 2023
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36. Nontraumatic atlantoaxial rotatory subluxation in adults: Report of two cases.
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Zhao X, Prather KY, Orenday-Barraza JM, Muhammad FY, Villeneuve LM, Cavagnaro MJ, Baaj AA, Dahdaleh NS, and Smith ZA
- Abstract
Background: Nontraumatic infectious atlantoaxial rotatory subluxation (AARS) is rare and less frequently encountered in adults versus children. We utilized a stepwise approach to treat two adults with nontraumatic infectious AARS and summarized the relevant literature., Case Description: Two patients, ages 35 and 66, presented with classic clinical and imaging findings for infectious nontraumatic AARS. Here, we summarized the management for these two patients along with the literature., Conclusion: Nontraumatic infectious AARS in adults requires prompt X-ray diagnosis and timely application of traction to minimize neurological deficits. MR/CT imaging next offers critical information regarding whether operative stabilization is warranted., Competing Interests: There are no conflicts of interest., (Copyright: © 2022 Surgical Neurology International.)
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- 2022
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37. Robot-Assisted Thoracolumbar Fixation After Acute Spinal Trauma: A Case Series.
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Villeneuve LM, Lee B, Cornwell B, Nagarajan M, and Smith ZA
- Abstract
Background: Pedicle screw fixation has become the workhorse for the stabilization of the thoracolumbar spine. Since accurate pedicle screw placement is necessary for a successful surgery, three-dimensional navigation has become a mainstay for placing pedicle screws. However, the published studies have an overrepresentation of lumbar screws despite the prevalence of thoracic fractures. Furthermore, no robotic-assisted pedicle screw study has focused solely on traumatic fractures. The goal of this study was to address whether (1) robot-assisted pedicle screw placement had comparable accuracy in the thoracic and thoracolumbar region and (2) robot-assisted spine surgery was feasible in an acute, traumatic setting., Methods: We performed 14 consecutive, thoracolumbar spinal stabilization procedures in which 126 pedicle screws were placed using the Globus ExcelsiusGPS® spine robot in an acute, traumatic setting. Operative times were measured, and the accuracy of pedicle screws was assessed with the Gertzbein and Robbins classification system by two board-certified neuroradiologists., Results: A total of 60-thoracic (T3-T11), the 24-thoracolumbar junction (T12-L1), 40-lumbar (L2-L5), and two-sacral pedicle screws were placed. Pedicle screw placement was accurate with a < 1% (1/126) pedicle breach rate. Thoracolumbar robotic spine surgery in an acute, traumatic setting was demonstrated to have a good safety profile with only one minor neurological deficit which was related to positioning. Furthermore, surgical times were inversely related to the case number., Conclusions: These results together suggest that robot-assisted spine surgery is accurate in the thoracic spine. Furthermore, placement of thoracolumbar screws in an acute trauma is non-inferior to other methods when based on accuracy., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2022, Villeneuve et al.)
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- 2022
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38. Effects of variability in manually contoured spinal cord masks on fMRI co-registration and interpretation.
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Hoggarth MA, Wang MC, Hemmerling KJ, Vigotsky AD, Smith ZA, Parrish TB, Weber KA 2nd, and Bright MG
- Abstract
Functional magnetic resonance imaging (fMRI) of the human spinal cord (SC) is a unique non-invasive method for characterizing neurovascular responses to stimuli. Group-analysis of SC fMRI data involves co-registration of subject-level data to standard space, which requires manual masking of the cord and may result in bias of group-level SC fMRI results. To test this, we examined variability in SC masks drawn in fMRI data from 21 healthy participants from a completed study mapping responses to sensory stimuli of the C7 dermatome. Masks were drawn on temporal mean functional image by eight raters with varying levels of neuroimaging experience, and the rater from the original study acted as a reference. Spatial agreement between rater and reference masks was measured using the Dice Similarity Coefficient, and the influence of rater and dataset was examined using ANOVA. Each rater's masks were used to register functional data to the PAM50 template. Gray matter-white matter signal contrast of registered functional data was used to evaluate the spatial normalization accuracy across raters. Subject- and group-level analyses of activation during left- and right-sided sensory stimuli were performed for each rater's co-registered data. Agreement with the reference SC mask was associated with both rater (F
(7, 140) = 32.12, P < 2 × 10-16 , η2 = 0.29) and dataset (F(20, 140) = 20.58, P < 2 × 10-16 , η2 = 0.53). Dataset variations may reflect image quality metrics: the ratio between the signal intensity of spinal cord voxels and surrounding cerebrospinal fluid was correlated with DSC results ( p < 0.001). As predicted, variability in the manually-drawn masks influenced spatial normalization, and GM:WM contrast in the registered data showed significant effects of rater and dataset (rater: F(8, 160) = 23.57, P < 2 × 10-16 , η2 = 0.24; dataset: F(20, 160) = 22.00, P < 2 × 10-16 , η2 = 0.56). Registration differences propagated into subject-level activation maps which showed rater-dependent agreement with the reference. Although group-level activation maps differed between raters, no systematic bias was identified. Increasing consistency in manual contouring of spinal cord fMRI data improved co-registration and inter-rater agreement in activation mapping, however our results suggest that improvements in image acquisition and post-processing are also critical to address., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The reviewer JC-A declared a past co-authorship with several of the authors ZS, TP, and KW to the handling Editor., (Copyright © 2022 Hoggarth, Wang, Hemmerling, Vigotsky, Smith, Parrish, Weber and Bright.)- Published
- 2022
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39. Utility of machine learning algorithms in degenerative cervical and lumbar spine disease: a systematic review.
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Stephens ME, O'Neal CM, Westrup AM, Muhammad FY, McKenzie DM, Fagg AH, and Smith ZA
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- Algorithms, Cervical Vertebrae surgery, Humans, Lumbar Vertebrae surgery, Machine Learning, Spinal Diseases diagnosis, Spinal Diseases surgery
- Abstract
Machine learning is a rapidly evolving field that offers physicians an innovative and comprehensive mechanism to examine various aspects of patient data. Cervical and lumbar degenerative spine disorders are commonly age-related disease processes that can utilize machine learning to improve patient outcomes with careful patient selection and intervention. The aim of this study is to examine the current applications of machine learning in cervical and lumbar degenerative spine disease. A systematic review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A search of PubMed, Embase, Medline, and Cochrane was conducted through May 31st, 2020, using the following terms: "artificial intelligence" OR "machine learning" AND "neurosurgery" AND "spine." Studies were included if original research on machine learning was utilized in patient care for degenerative spine disease, including radiographic machine learning applications. Studies focusing on robotic applications in neurosurgery, navigation, or stereotactic radiosurgery were excluded. The literature search identified 296 papers, with 35 articles meeting inclusion criteria. There were nine studies involving cervical degenerative spine disease and 26 studies on lumbar degenerative spine disease. The majority of studies for both cervical and lumbar spines utilized machine learning for the prediction of postoperative outcomes, with 5 (55.6%) and 15 (61.5%) studies, respectively. Machine learning applications focusing on degenerative lumbar spine greatly outnumber the current volume of cervical spine studies. The current research in lumbar spine also demonstrates more advanced clinical applications of radiographic, diagnostic, and predictive machine learning models., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
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- 2022
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40. A combined approach for stabilization and endoscopic/ endonasal odontoid and clivus resection for treatment of basilar invagination.
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Villeneuve LM, Voronovich Z, Evans A, El Rassi ET, Dunn IF, and Smith ZA
- Abstract
Background: Basilar invagination (BI) is a complex condition characterized by prolapse of the odontoid into the brain stem/upper cervical cord. This lesion is often associated with Chiari malformations, and rheumatoid arthritis (RA). Treatment options for BI typically include cervical traction, an isolated anterior transoral odontoidectomy, anterior endonasal odontoidectomy, an isolated posterior fusion, or combined anterior/ posterior surgical approach., Case Description: A 45-year-old female with a Chiari I malformation and RA underwent a combined posterior C0-C5 posterior decompression/fusion, followed by an anterior odontoidectomy (i.e. endoscopic/endonasal under neuronavigation). Postoperatively, the patient's symptoms and neurological signs resolved., Conclusion: BI in was successfully managed with a combined posterior C0-C5 decompression/fusion followed by an anterior endoscopic/endonasal odontoidectomy performed under neuronavigation., Competing Interests: There are no conflicts of interest., (Copyright: © 2021 Surgical Neurology International.)
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- 2021
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41. Generic acquisition protocol for quantitative MRI of the spinal cord.
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Cohen-Adad J, Alonso-Ortiz E, Abramovic M, Arneitz C, Atcheson N, Barlow L, Barry RL, Barth M, Battiston M, Büchel C, Budde M, Callot V, Combes AJE, De Leener B, Descoteaux M, de Sousa PL, Dostál M, Doyon J, Dvorak A, Eippert F, Epperson KR, Epperson KS, Freund P, Finsterbusch J, Foias A, Fratini M, Fukunaga I, Wheeler-Kingshott CAMG, Germani G, Gilbert G, Giove F, Gros C, Grussu F, Hagiwara A, Henry PG, Horák T, Hori M, Joers J, Kamiya K, Karbasforoushan H, Keřkovský M, Khatibi A, Kim JW, Kinany N, Kitzler H, Kolind S, Kong Y, Kudlička P, Kuntke P, Kurniawan ND, Kusmia S, Labounek R, Laganà MM, Laule C, Law CS, Lenglet C, Leutritz T, Liu Y, Llufriu S, Mackey S, Martinez-Heras E, Mattera L, Nestrasil I, O'Grady KP, Papinutto N, Papp D, Pareto D, Parrish TB, Pichiecchio A, Prados F, Rovira À, Ruitenberg MJ, Samson RS, Savini G, Seif M, Seifert AC, Smith AK, Smith SA, Smith ZA, Solana E, Suzuki Y, Tackley G, Tinnermann A, Valošek J, Van De Ville D, Yiannakas MC, Weber KA 2nd, Weiskopf N, Wise RG, Wyss PO, and Xu J
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- Humans, Male, Adult, Image Processing, Computer-Assisted methods, Female, Spinal Cord diagnostic imaging, Magnetic Resonance Imaging methods
- Abstract
Quantitative spinal cord (SC) magnetic resonance imaging (MRI) presents many challenges, including a lack of standardized imaging protocols. Here we present a prospectively harmonized quantitative MRI protocol, which we refer to as the spine generic protocol, for users of 3T MRI systems from the three main manufacturers: GE, Philips and Siemens. The protocol provides guidance for assessing SC macrostructural and microstructural integrity: T1-weighted and T2-weighted imaging for SC cross-sectional area computation, multi-echo gradient echo for gray matter cross-sectional area, and magnetization transfer and diffusion weighted imaging for assessing white matter microstructure. In a companion paper from the same authors, the spine generic protocol was used to acquire data across 42 centers in 260 healthy subjects. The key details of the spine generic protocol are also available in an open-access document that can be found at https://github.com/spine-generic/protocols . The protocol will serve as a starting point for researchers and clinicians implementing new SC imaging initiatives so that, in the future, inclusion of the SC in neuroimaging protocols will be more common. The protocol could be implemented by any trained MR technician or by a researcher/clinician familiar with MRI acquisition., (© 2021. The Author(s), under exclusive licence to Springer Nature Limited.)
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- 2021
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42. Author Correction: Open-access quantitative MRI data of the spinal cord and reproducibility across participants, sites and manufacturers.
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Cohen-Adad J, Alonso-Ortiz E, Abramovic M, Arneitz C, Atcheson N, Barlow L, Barry RL, Barth M, Battiston M, Büchel C, Budde M, Callot V, Combes AJE, De Leener B, Descoteaux M, de Sousa PL, Dostál M, Doyon J, Dvorak A, Eippert F, Epperson KR, Epperson KS, Freund P, Finsterbusch J, Foias A, Fratini M, Fukunaga I, Gandini Wheeler-Kingshott CAM, Germani G, Gilbert G, Giove F, Gros C, Grussu F, Hagiwara A, Henry PG, Horák T, Hori M, Joers J, Kamiya K, Karbasforoushan H, Keřkovský M, Khatibi A, Kim JW, Kinany N, Kitzler HH, Kolind S, Kong Y, Kudlička P, Kuntke P, Kurniawan ND, Kusmia S, Labounek R, Laganà MM, Laule C, Law CS, Lenglet C, Leutritz T, Liu Y, Llufriu S, Mackey S, Martinez-Heras E, Mattera L, Nestrasil I, O'Grady KP, Papinutto N, Papp D, Pareto D, Parrish TB, Pichiecchio A, Prados F, Rovira À, Ruitenberg MJ, Samson RS, Savini G, Seif M, Seifert AC, Smith AK, Smith SA, Smith ZA, Solana E, Suzuki Y, Tackley G, Tinnermann A, Valošek J, Van De Ville D, Yiannakas MC, Weber Ii KA, Weiskopf N, Wise RG, Wyss PO, and Xu J
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- 2021
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43. Open-access quantitative MRI data of the spinal cord and reproducibility across participants, sites and manufacturers.
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Cohen-Adad J, Alonso-Ortiz E, Abramovic M, Arneitz C, Atcheson N, Barlow L, Barry RL, Barth M, Battiston M, Büchel C, Budde M, Callot V, Combes AJE, De Leener B, Descoteaux M, de Sousa PL, Dostál M, Doyon J, Dvorak A, Eippert F, Epperson KR, Epperson KS, Freund P, Finsterbusch J, Foias A, Fratini M, Fukunaga I, Gandini Wheeler-Kingshott CAM, Germani G, Gilbert G, Giove F, Gros C, Grussu F, Hagiwara A, Henry PG, Horák T, Hori M, Joers J, Kamiya K, Karbasforoushan H, Keřkovský M, Khatibi A, Kim JW, Kinany N, Kitzler HH, Kolind S, Kong Y, Kudlička P, Kuntke P, Kurniawan ND, Kusmia S, Labounek R, Laganà MM, Laule C, Law CS, Lenglet C, Leutritz T, Liu Y, Llufriu S, Mackey S, Martinez-Heras E, Mattera L, Nestrasil I, O'Grady KP, Papinutto N, Papp D, Pareto D, Parrish TB, Pichiecchio A, Prados F, Rovira À, Ruitenberg MJ, Samson RS, Savini G, Seif M, Seifert AC, Smith AK, Smith SA, Smith ZA, Solana E, Suzuki Y, Tackley G, Tinnermann A, Valošek J, Van De Ville D, Yiannakas MC, Weber Ii KA, Weiskopf N, Wise RG, Wyss PO, and Xu J
- Subjects
- Adult, Female, Humans, Image Processing, Computer-Assisted, Male, Reproducibility of Results, Magnetic Resonance Imaging, Neuroimaging, Spinal Cord diagnostic imaging, Spinal Cord ultrastructure
- Abstract
In a companion paper by Cohen-Adad et al. we introduce the spine generic quantitative MRI protocol that provides valuable metrics for assessing spinal cord macrostructural and microstructural integrity. This protocol was used to acquire a single subject dataset across 19 centers and a multi-subject dataset across 42 centers (for a total of 260 participants), spanning the three main MRI manufacturers: GE, Philips and Siemens. Both datasets are publicly available via git-annex. Data were analysed using the Spinal Cord Toolbox to produce normative values as well as inter/intra-site and inter/intra-manufacturer statistics. Reproducibility for the spine generic protocol was high across sites and manufacturers, with an average inter-site coefficient of variation of less than 5% for all the metrics. Full documentation and results can be found at https://spine-generic.rtfd.io/ . The datasets and analysis pipeline will help pave the way towards accessible and reproducible quantitative MRI in the spinal cord., (© 2021. The Author(s).)
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- 2021
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44. Robotics in spine surgery: A systematic review.
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McKenzie DM, Westrup AM, O'Neal CM, Lee BJ, Shi HH, Dunn IF, Snyder LA, and Smith ZA
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- Humans, Learning Curve, Neurosurgical Procedures instrumentation, Pedicle Screws, Prospective Studies, Radiation Exposure prevention & control, Randomized Controlled Trials as Topic methods, Retrospective Studies, Robotic Surgical Procedures instrumentation, Spinal Diseases diagnosis, Surgeons trends, Surgery, Computer-Assisted instrumentation, Neurosurgical Procedures methods, Robotic Surgical Procedures methods, Spinal Diseases surgery, Spine surgery, Surgery, Computer-Assisted methods
- Abstract
Robotic systems to assist with pedicle screw placement have recently emerged in the field of spine surgery. Here, the authors systematically reviewed the literature for evidence of these robotic systems and their utility. Thirty-four studies that reported the use of spinal instrumentation with robotic assistance and met inclusion criteria were identified. The outcome measures gathered included: pedicle screw accuracy, indications for surgery, rates of conversion to an alternative surgical method, radiation exposure, and learning curve. In our search there were five different robotic systems identified. All studies reported accuracy and the most commonly used accuracy grading scale was the Gertzbein Robbins scale (GRS). Accuracy of clinically acceptable pedicle screws, defined as < 2 mm cortical breech, ranged from 80% to 100%. Many studies categorized indications for robotic surgery with the most common being degenerative entities. Some studies reported rates of conversion from robotic assistance to manual instrumentation due to many reasons, with robotic failure as the most common. Radiation exposure data revealed a majority of studies reported less radiation using robotic systems. Studies looking at a learning curve effect with surgeon use of robotic assistance were not consistent across the literature. Robotic systems for assistance in spine surgery have continued to improve and the accuracy of pedicle screw placement remains superior when compared to free-hand technique, however rates of manual conversion are significant. Currently, these systems are successfully employed in various pathological entities where trained spine surgeons can be safe and accurate regardless of robotic training., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Ltd. All rights reserved.)
- Published
- 2021
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45. Fatty infiltration in cervical flexors and extensors in patients with degenerative cervical myelopathy using a multi-muscle segmentation model.
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Paliwal M, Weber KA 2nd, Smith AC, Elliott JM, Muhammad F, Dahdaleh NS, Bodurka J, Dhaher Y, Parrish TB, Mackey S, and Smith ZA
- Subjects
- Cervical Vertebrae diagnostic imaging, Cervical Vertebrae metabolism, Cervical Vertebrae pathology, Female, Humans, Male, Middle Aged, Musculoskeletal System metabolism, Musculoskeletal System pathology, Musculoskeletal System surgery, Neck pathology, Neck surgery, Neck Muscles metabolism, Neck Muscles pathology, Neck Muscles surgery, Paraspinal Muscles, Recovery of Function physiology, Spinal Cord Compression pathology, Spinal Cord Compression surgery, Spinal Cord Diseases diagnostic imaging, Spinal Cord Diseases metabolism, Spinal Cord Diseases pathology, Spondylosis diagnostic imaging, Spondylosis metabolism, Spondylosis pathology, Treatment Outcome, Cervical Vertebrae surgery, Decompression, Surgical, Spinal Cord Diseases surgery, Spondylosis surgery
- Abstract
Background: In patients with degenerative cervical myelopathy (DCM) that have spinal cord compression and sensorimotor deficits, surgical decompression is often performed. However, there is heterogeneity in clinical presentation and post-surgical functional recovery., Objectives: Primary: a) to assess differences in muscle fat infiltration (MFI) in patients with DCM versus controls, b) to assess association between MFI and clinical disability. Secondary: to assess association between MFI pre-surgery and post-surgical functional recovery., Study Design: Cross-sectional case control study., Methods: Eighteen patients with DCM (58.6 ± 14.2 years, 10 M/8F) and 25 controls (52.6 ± 11.8 years, 13M/12 F) underwent 3D Dixon fat-water imaging. A convolutional neural network (CNN) was used to segment cervical muscles (MFSS- multifidus and semispinalis cervicis, LC- longus capitis/colli) and quantify MFI. Modified Japanese Orthopedic Association (mJOA) and Nurick were collected., Results: Patients with DCM had significantly higher MFI in MFSS (20.63 ± 5.43 vs 17.04 ± 5.24, p = 0.043) and LC (18.74 ± 6.7 vs 13.66 ± 4.91, p = 0.021) than controls. Patients with increased MFI in LC and MFSS had higher disability (LC: Nurick (Spearman's ρ = 0.436, p = 0.003) and mJOA (ρ = -0.399, p = 0.008)). Increased MFI in LC pre-surgery was associated with post-surgical improvement in Nurick (ρ = -0.664, p = 0.026) and mJOA (ρ = -0.603, p = 0.049)., Conclusion: In DCM, increased muscle adiposity is significantly associated with sensorimotor deficits, clinical disability, and functional recovery after surgery. Accurate and time efficient evaluation of fat infiltration in cervical muscles may be conducted through implementation of CNN models., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2021
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46. An Evaluation of Neurosurgical Practices During the Coronavirus Disease 2019 Pandemic.
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Pelargos PE, Chakraborty AR, Adogwa O, Swartz K, Zhao YD, Smith ZA, Dunn IF, and Bauer AM
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- COVID-19 prevention & control, Health Personnel standards, Health Personnel trends, Humans, Neurosurgeons standards, Neurosurgical Procedures standards, Pandemics prevention & control, Personal Protective Equipment standards, Personal Protective Equipment trends, United States epidemiology, Workforce standards, Workforce trends, COVID-19 epidemiology, Neurosurgeons trends, Neurosurgical Procedures trends, Surveys and Questionnaires standards
- Abstract
Objective: We sought to understand how the coronavirus disease 2019 pandemic has affected the neurosurgical workforce., Methods: We created a survey consisting of 22 questions to assess the respondent's operative experience, location, type of practice, subspecialty, changes in clinic and operative volumes, changes to staff, and changes to income since the pandemic began. The survey was distributed electronically to neurosurgeons throughout the United States and Puerto Rico., Results: Of the 724 who opened the survey link, 457 completed the survey. The respondents were from throughout the United States and Puerto Rico and represented all practices types and subspecialties. Nearly all respondents reported hospital restrictions on elective surgeries. Most reported a decline in clinic and operative volume. Nearly 70% of respondents saw a decrease in the work hours of their ancillary providers, and almost one half (49.1%) of the respondents had had to downsize their practice staff, office assistants, nurses, schedulers, and other personnel. Overall, 43.6% of survey respondents had experienced a decline in income, and 27.4% expected a decline in income in the upcoming billing cycle. More senior neurosurgeons and those with a private practice, whether solo or as part of a group, were more likely to experience a decline in income as a result of the pandemic compared with their colleagues., Conclusion: The coronavirus disease 2019 pandemic will likely have a lasting effect on the practice of medicine. Our survey results have described the early effects on the neurosurgical workforce. Nearly all neurosurgeons experienced a significant decline in clinical volume, which led to many downstream effects. Ultimately, analysis of the effects of such a pervasive pandemic will allow the neurosurgical workforce to be better prepared for similar events in the future., (Copyright © 2020 Elsevier Inc. All rights reserved.)
- Published
- 2021
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47. Long-term outcomes of spinal ependymomas: an institutional experience of more than 60 cases.
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Savoor R, Sita TL, Dahdaleh NS, Helenowski I, Kalapurakal JA, Marymont MH, Lukas R, Kruser TJ, Smith ZA, Koski T, Ganju A, and Sachdev S
- Subjects
- Adult, Aged, Aged, 80 and over, Combined Modality Therapy, Ependymoma pathology, Ependymoma therapy, Female, Follow-Up Studies, Humans, Male, Middle Aged, Prognosis, Retrospective Studies, Spinal Cord Neoplasms pathology, Spinal Cord Neoplasms therapy, Survival Rate, Young Adult, Ependymoma mortality, Neurosurgical Procedures mortality, Radiotherapy, Adjuvant mortality, Spinal Cord Neoplasms mortality
- Abstract
Purpose: Spinal ependymomas represent the most common primary intramedullary tumors for which optimal management remains undefined. When possible, gross total resection (GTR) is often the mainstay of treatment, with consideration of radiotherapy (RT) in cases of residual or recurrent tumor. The impact of extent of resection and radiotherapy remain understudied., Objective: Report on a large institutional cohort with lengthy follow-up to provide information on long-term outcomes and to contribute to limited data assessing the value of extent of resection and RT., Methods: Patients with pathologically proven primary spinal ependymoma between 1990 and 2018 were identified. Kaplan-Meier estimates were used to calculate progression-free survival (PFS); local-control (LC) and overall survival (OS). Logistic regression was used to analyze variables' association with receipt of RT., Results: We identified 69 patients with ependymoma of which 4 had leptomeningeal dissemination at diagnosis and were excluded. Of the remaining cohort (n = 65), 42 patients (65%) had Grade II spinal ependymoma, 20 (31%) had Grade I myxopapillary ependymoma and 3 (5%) had Grade III anaplastic ependymoma; 54% underwent GTR and 39% underwent RT. With a median follow-up of 5.7 years, GTR was associated with improved PFS. For grade II lesions, STR+RT yielded better outcomes than STR alone (10y PFS 77.1% vs 68.2%, LC 85.7% vs 50%). Degree of resection was the only significant predictor of adjuvant radiotherapy (p < 0.0001)., Conclusion: Our findings confirm the importance of GTR in spinal ependymomas. Adjuvant RT should be utilized in the setting of a subtotal resection with expectation of improved disease-related outcomes.
- Published
- 2021
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48. Macromolecular changes in spinal cord white matter characterize whiplash outcome at 1-year post motor vehicle collision.
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Hoggarth MA, Elliott JM, Smith ZA, Paliwal M, Kwasny MJ, Wasielewski M, Weber KA 2nd, and Parrish TB
- Subjects
- Adult, Analysis of Variance, Female, Humans, Image Processing, Computer-Assisted, Magnetic Resonance Imaging, Male, Spinal Cord diagnostic imaging, Spinal Cord Injuries etiology, Spinal Cord Injuries metabolism, Spinal Cord Injuries pathology, Time Factors, White Matter diagnostic imaging, Biomarkers, Spinal Cord metabolism, Spinal Cord pathology, White Matter metabolism, White Matter pathology
- Abstract
Each year, whiplash injuries from motor vehicle collisions (MVC) affect millions worldwide, with no strong evidence of pathology. While the majority recover soon after the injury, the same is not true for roughly 20% reporting higher levels of pain and distress, without diagnostic options. This study used magnetization transfer (MT) imaging to quantify white matter integrity in 78 subjects with varying levels of pain, 1 year after MVC. MT images of the cervical spinal cord were collected parallel to the intervertebral disks. MT ratios (MTR) were calculated in select white matter tracts along with MTR homogeneity (MTRh) at each level. Significant differences were observed between clinical outcome groups in the left and right spinothalamic tracts (p = 0.003 and 0.020) and MTRh (p = 0.009). MTRh was elevated in females with poor recovery versus females reporting recovery (p < 0.001) or milder symptoms (p < 0.001), and in males reporting recovery (p = 0.007) or no recovery (p < 0.001). There was a significant interaction between recovery status and sex (p = 0.015). MT imaging identified tract specific and regional changes in white matter integrity suggesting potential insults to the cord. Additionally, significant MTRh differences between sexes were observed, characterizing the heterogeneity of whiplash recovery and worse outcomes in females.
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- 2020
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49. Comparison of dalbavancin to standard-of-care for outpatient treatment of invasive Gram-positive infections.
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Veve MP, Patel N, Smith ZA, Yeager SD, Wright LR, and Shorman MA
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- Adult, Endocarditis drug therapy, Endocarditis microbiology, Female, Gram-Positive Bacteria drug effects, Humans, Male, Middle Aged, Osteomyelitis drug therapy, Osteomyelitis microbiology, Outpatients, Retrospective Studies, Teicoplanin therapeutic use, Anti-Bacterial Agents therapeutic use, Daptomycin therapeutic use, Gram-Positive Bacterial Infections drug therapy, Teicoplanin analogs & derivatives, Vancomycin therapeutic use
- Abstract
Objective: To assess the efficacy and safety of dalbavancin compared to standard-of-care (SOC) or vancomycin and daptomycin in invasive infections due to suspected or confirmed Gram-positive organisms., Methods: Retrospective cohort of adults who received dalbavancin or SOC on discharge or as an outpatient from 12/2016 to 11/2019. Indications were osteoarticular infection (OAI), infective endocarditis (IE), or other bloodstream infection (BSI). Primary endpoint was 90-day infection-related readmission (IRR); secondary endpoints included time-to-IRR, frequency of adverse drug events (ADEs), and all-cause readmission and mortality., Results: 215 patients were included: 70 (33%) receiving dalbavancin, and 145 (67%) receiving SOC. Indications were OAI (47%), IE (27%), and other BSI (26%). OAI was more common in patients on dalbavancin compared with those receiving SOC (70% vs. 37%, P<0.001). Dalbavancin patients had shorter median (interquartile range [IQR]) length of stay (LOS) prior to drug initiation compared with those receiving SOC (10 [7-17] vs. 13 [9-19], P=0.021). IRR incidence was 17% for dalbavancin patients and 28% for SOC patients. Dalbavancin use was independently associated with lower IRR (adjusted odds ratio [adjOR], 0.10; 95% confidence interval [CI], 0.04-0.31). There was longer median (IQR) time-to-IRR in the dalbavancin group (43 [30-87] vs. 23 [11-63] days, P=0.039), but no differences in all-cause readmission or mortality. Treatment-related ADE incidence was 3% and 14% for the dalbavancin and SOC groups, respectively (P=0.013). Infusion reactions (1/2) and catheter-related complications (1/2) were the most common dalbavancin ADEs; catheter-related complications (14/21), nephrotoxicity (3/21), rhabdomyolysis (2/21), and rash (2/21) were the most common SOC ADEs., Conclusions: Dalbavancin use was associated with lower 90-day IRR, a shorter hospital LOS prior to therapy, and longer time-to-IRR compared with SOC., (Copyright © 2020 Elsevier Ltd. All rights reserved.)
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- 2020
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50. Magnetization Transfer Ratio and Morphometrics of the Spinal Cord Associates with Surgical Recovery in Patients with Degenerative Cervical Myelopathy.
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Paliwal M, Weber KA 2nd, Hopkins BS, Cantrell DR, Hoggarth MA, Elliott JM, Dahdaleh NS, Mackey S, Parrish TD, Dhaher Y, and Smith ZA
- Subjects
- Cohort Studies, Female, Humans, Image Processing, Computer-Assisted, Male, Middle Aged, Pain, Postoperative diagnostic imaging, Pain, Postoperative etiology, Sensitivity and Specificity, Treatment Outcome, White Matter diagnostic imaging, White Matter surgery, Magnetic Resonance Imaging methods, Spinal Cord Diseases diagnostic imaging, Spinal Cord Diseases surgery, Spondylosis diagnostic imaging, Spondylosis surgery
- Abstract
Objectives: We assessed the prognostic value of the preoperative magnetization transfer ratio (MTR) and morphometrics of the spinal cord in patients with degenerative cervical myelopathy (DCM) in a longitudinal cohort study., Methods: Thirteen subjects with DCM underwent 3T magnetization transfer imaging. The MTR was calculated for the spinal cord regions and specific white matter tracts. Morphometric measures were extracted. Clinical (modified Japanese Orthopaedics Association [mJOA] and Nurick scale scores) and health-related quality of life scores were assessed before and after cervical decompression surgery. The association between the magnetic resonance imaging (MRI) metrics and postoperative recovery was assessed (Spearman's correlation). Receiver operating characteristics were used to assess the accuracy of MRI metrics in identifying ≥50% recovery in function., Results: Preoperative anterior cord MTRs were associated with recovery in mJOA scores (ρ = 0.608; P = 0.036; area under the curve [AUC], 0.66). Preoperative lateral cord MTR correlated with the neck disability index (ρ = 0.699; P = 0.011) and pain interference scale (ρ = 0.732; P = 0.007). Preoperative rubrospinal tract MTR was associated with mJOA score recovery (ρ = 0.573; P = 0.041; AUC, 0.86). Preoperative corticospinal tract and reticulospinal MTRs were related to recovery in pain interference scores (ρ = 0.591; P = 0.033; and ρ = 0.583; P = 0.035, respectively). Eccentricity of the cord was associated with Nurick scores (ρ = 0.606; P = 0.028) and mJOA scores (ρ = 0.651; P = 0.025; AUC, 0.92)., Conclusions: Preoperative MTR and eccentricity measurements of the spinal cord have prognostic value in assessing the response to surgery and recovery in patients with DCM. Advanced MRI and atlas-based postprocessing techniques can inform interventions and advance the healthcare received by patients with DCM., (Copyright © 2020 Elsevier Inc. All rights reserved.)
- Published
- 2020
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