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Abstract: Background context: Postoperative back pain is common after decompression surgery for lumbar stenosis and often delays discharge from hospital. Achieving regional analgesia by intraoperative delivery of epidural opiates after lumbar canal decompression is a promising approach to reduce postoperative pain and enhance early mobilization. However, there have been concerns about opiate-related complications, such as respiratory depression and urinary retention in what is generally an elderly population of patients. Purpose: To assess the analgesic efficacy of bolus epidural fentanyl administered intraoperatively after lumbar decompression for degenerative canal stenosis. Study design/setting: Patient-blinded randomized controlled trial conducted at two university neurosurgical centers. Patient sample: Adults (older than 18 years) with neurogenic claudication and/or lower limb radiculopathy and concordant lumbar spinal canal stenosis demonstrated on magnetic resonance imaging. Patients with previous lumbar spinal surgery, a contraindication to fentanyl, or requiring instrumentation were excluded. Outcome measures: The primary outcome measure was patient-reported Visual Analogue Score (VAS) for pain recorded preoperatively, in recovery, and on the first and second postoperative days if the patient remained in the hospital. Secondary outcomes were duration of surgery, length of stay, and any side effects or complications. Methods: Patients underwent a one to three level lumbar canal decompression as required, via a midline incision, under general anesthesia. Before wound closure either no drug (control) or a 100-μg bolus of fentanyl was administered via an epidural catheter inserted 10 cm rostral to the operated level. Patients were blinded to group allocation, and analysis was by intention to treat. The trial was approved by the National Health Service Research Ethics Service and the Medicines and Healthcare products Regulatory Agency. No commercial or other source of funding was received. Results: Sixty patients were randomized, 29 to fentanyl and 31 to control. Demographics, duration of surgery, and preoperative VAS were not significantly different between the groups. VAS in recovery was significantly lower in patients treated with fentanyl (mean [standard deviation]: 2.6 [2.7] vs. 4.7 [2.4]; p=.003). Later VAS and postoperative length of stay were similar between groups. More patients in the fentanyl group required temporary urinary catheterization, but there was no significant difference in the incidence of side effects. Conclusions: Bolus epidural fentanyl provides effective short-term postoperative analgesia after lumbar canal decompression and may be a useful adjunct to pain management in patients undergoing lumbar spine surgery. [Copyright &y& Elsevier]

Abstract: Background: Using bone morphogenic protein (BMP) to augment fusion in spine surgery is widespread and lends itself in particular to minimally invasive lumbar fusion, where the surface area for fusion is significantly less than the equivalent open procedure. Purpose: Here we described the use of very low–dose BMP in promoting fusion in minimally invasive lumbar interbody fixation but also highlight some of the potential complications of BMP-2 use and techniques available to reduce or avoid them. Study design: Prospective observational study of consecutive patients undergoing minimally invasive lumbar interbody fusion with percutaneous pedicle screws. Patient sample: Thirty patients aged between 22 and 78 years (mean 53 years). Outcome measures: Thin-slice lumbar computed tomography scanning with multiplanar reconstruction at 6 and 12 months postoperative. Methods: Thirty-six spinal levels were instrumented in total, of which four underwent posterior lumbar interbody fusion and 32 underwent transforaminal lumbar interbody fusion. Bone graft harvested locally was placed in the disc space with low-dose BMP-2 (1.4 mg per level). Results: Thirty-three of 36 spinal levels showed complete fusion at a mean postoperative scan time of 7.1 months. Two levels demonstrated partial fusion at 6 months, which was complete at 12 months. There was one case of nonunion at 12 months, which also demonstrated vertebral body osteolysis. Despite very low–dose BMP-2, two cases of asymptomatic heterotopic ossification were observed, and there were two cases of perineural cyst formation, one of whom required revision of the interbody cage. Conclusions: The use of BMP with autograft in the disc space during minimally invasive lumbar interbody fusion is associated with a high rate of early fusion. Even with very low–dose BMP used in this study, complications related to BMP usage were not avoided completely. [Copyright &y& Elsevier]

Background: Adequate pain assessment is critical for evaluating the efficacy of analgesic treatment in clinical practice and during the development of new therapies. Yet the currently used scores of global pain intensity fail to reflect the diversity of pain manifestations and the complexity of underlying biological mechanisms. We have developed a tool for a standardized assessment of pain-related symptoms and signs that differentiates pain phenotypes independent of etiology. Methods and Findings: Using a structured interview (16 questions) and a standardized bedside examination (23 tests), we prospectively assessed symptoms and signs in 130 patients with peripheral neuropathic pain caused by diabetic polyneuropathy, postherpetic neuralgia, or radicular low back pain (LBP), and in 57 patients with non-neuropathic (axial) LBP. A hierarchical cluster analysis revealed distinct association patterns of symptoms and signs (pain subtypes) that characterized six subgroups of patients with neuropathic pain and two subgroups of patients with non-neuropathic pain. Using a classification tree analysis, we identified the most discriminatory assessment items for the identification of pain subtypes. We combined these six interview questions and ten physical tests in a pain assessment tool that we named Standardized Evaluation of Pain (StEP). We validated StEP for the distinction between radicular and axial LBP in an independent group of 137 patients. StEP identified patients with radicular pain with high sensitivity (92%; 95% confidence interval [CI] 83%-97%) and specificity (97%; 95% CI 89%-100%). The diagnostic accuracy of StEP exceeded that of a dedicated screening tool for neuropathic pain and spinal magnetic resonance imaging. In addition, we were able to reproduce subtypes of radicular and axial LBP, underscoring the utility of StEP for discerning distinct constellations of symptoms and signs. Conclusions: We present a novel method of identifying pain subtypes that we believe reflect underlying pain mechanisms. We demonstrate that this new approach to pain assessment helps separate radicular from axial back pain. Beyond diagnostic utility, a standardized differentiation of pain subtypes that is independent of disease etiology may offer a unique opportunity to improve targeted analgesic treatment. [ABSTRACT FROM AUTHOR]

Discusses theories about peripheral neuropathic pain and shows that progress in management is contingent on targeting treatment at the mechanisms that operate to produce the symptoms. Pathophysiology of neuropathic pain; Etiology; Question of why nerve injury causes pain; Symptoms; Mechanism of peripheral neuropathic pain.

Background L-[methyl-11C]-methionine-positron emission tomography (Met-PET) is a potentially important imaging adjunct in the diagnostic workup of pituitary adenomas, including somatotroph tumors. Met-PET can identify residual or occult disease and make definitive therapies accessible to a subgroup of patients who would otherwise require lifelong medical therapy. However, existing data on its use are still limited to small case series. Here, we report the largest single-center experience (n = 61) in acromegaly. Methods A total of 189 cases of acromegaly were referred to our national Met-PET service in the last 12 years. For this analysis, we have reviewed outcomes in those 61 patients managed exclusively by our multidisciplinary team (single center, single surgeon). Referral indications were as follows: indeterminate magnetic resonance imaging (MRI; n = 38, 62.3%), occult residual (n = 14, 23.0%), (radio-)surgical planning (n = 6, 9.8%), and occult de novo tumor (n = 3, 4.9%). Results A total of 33/61 patients (54.1%) underwent PET-guided surgery. Twenty-four of 33 patients (72.7%) achieved complete biochemical remission following (re-)surgery. Insulin-like growth factor 1 levels were reduced to <2 × upper limit of normal (ULN) in 6 of the remaining 9 cases, 3 of whom achieved levels of <1.1 × ULN compared with mean preoperative levels of 2.4 × ULN (SD 0.8) for n = 9. Only 3 patients developed single new hormonal deficits (gonadotropic/thyrotropic insufficiency). There were no neurovascular complications after surgery. Conclusion In patients with persistent/recurrent acromegaly or occult tumors, Met-PET can facilitate further targeted intervention (surgery/radiosurgery). This led to complete remission in most cases (24/33) or significant improvement with comparatively low risk of complications. L-[methyl-11C]-methionine-positron emission tomography should therefore be considered in all patients who are potential candidates for further surgical intervention but present no clear target on MRI. [ABSTRACT FROM AUTHOR]

The endonasal transsphenoidal approach (TSA) has emerged as the preferred approach in order to treat pituitary adenoma and related sellar pathologies. The recently adopted expanded endonasal approach (EEA) has improved access to the ventral skull base whilst retaining the principles of minimally invasive surgery. Despite the advantages these approaches offer, cerebrospinal fluid (CSF) rhinorrhoea remains a common complication. There is currently a lack of comparative evidence to guide the best choice of skull base reconstruction, resulting in considerable heterogeneity of current practice. This study aims to determine: (1) the scope of the methods of skull base repair; and (2) the corresponding rates of postoperative CSF rhinorrhoea in contemporary neurosurgical practice in the UK and Ireland. We will adopt a multicentre, prospective, observational cohort design. All neurosurgical units in the UK and Ireland performing the relevant surgeries (TSA and EEA) will be eligible to participate. Eligible cases will be prospectively recruited over 6 months with 6 months of postoperative follow-up. Data points collected will include: demographics, tumour characteristics, operative data), and postoperative outcomes. Primary outcomes include skull base repair technique and CSF rhinorrhoea (biochemically confirmed and/or requiring intervention) rates. Pooled data will be analysed using descriptive statistics. All skull base repair methods used and CSF leak rates for TSA and EEA will be compared against rates listed in the literature. Formal institutional ethical board review was not required owing to the nature of the study – this was confirmed with the Health Research Authority, UK. The need for this multicentre, prospective, observational study is highlighted by the relative paucity of literature and the resultant lack of consensus on the topic. It is hoped that the results will give insight into contemporary practice in the UK and Ireland and will inform future studies. [ABSTRACT FROM AUTHOR]

Introduction: Magnetic resonance imaging (MRI) is gold-standard for investigating Degenerative Cervical Myelopathy (DCM), a disabling disease triggered by compression of the spinal cord following degenerative changes of adjacent structures. Quantifiable compression correlates poorly with disease and language describing compression in radiological reports is un-standardised. Study design: Retrospective chart review. Objectives: 1) Identify terminology in radiological reporting of cord compression and elucidate relationships between language and quantitative measures 2) Evaluate language’s ability to distinguish myelopathic from asymptomatic compression 3) Explore correlations between quantitative or qualitative features and symptom severity 4) Investigate the influence of quantitative and qualitative measures on surgical referrals. Methods: From all cervical spine MRIs conducted during one year at a tertiary centre (N = 1123), 166 patients had reported cord compression. For each spinal level deemed compressed by radiologists (N = 218), four quantitative measurements were calculated: ‘Maximum Canal Compromise (MCC); ‘Maximum Spinal Cord Compression’ (MSCC); ‘Spinal Canal Occupation Ratio’ (SCOR) and ‘Compression Ratio’ (CR). These were compared to associated radiological reporting terminology. Results: 1) Terminology in radiological reports was varied. Objective measures of compromise correlated poorly with language. “Compressed” was used for more severe cord compromise as measured by MCC (p<0.001), MSCC (p<0.001), and CR (p = 0.002). 2) Greater compromise was seen in cords with a myelopathy diagnosis across MCC (p<0.001); MSCC (p = 0.002) and CR (p<0.001). “Compress” (p<0.001) and “Flatten” (p<0.001) were used more commonly for myelopathy-diagnosis levels. 3) Measurements of cord compromise (MCC: p = 0.304; MSCC: p = 0.217; SCOR: p = 0.503; CR: p = 0.256) and descriptive terms (p = 0.591) did not correlate with i-mJOA score. 4) The only variables affecting spinal surgery referral were increased MSCC (p = 0.001) and use of ‘Compressed’ (p = 0.045). Conclusions: Radiological reporting in DCM is variable and language is not fully predictive of the degree of quantitative cord compression. Additionally, terminology may influence surgical referrals. [ABSTRACT FROM AUTHOR]

No healthcare workers (HCWs) inside the operating room (OR) were subsequently diagnosed with COVID-19, although HCWs managing the patients without personal protective equipment (PPE) outside the OR did contract the virus. We have adopted a risk mitigation approach for use during the COVID-19 pandemic (Table 1), as we believe that patients who require expedited surgery for a pituitary or skull base lesion due to progressive neurological or visual symptoms should still receive urgent treatment. A risk mitigation strategy is feasible and can enable timely pituitary and other skull base surgery to continue safely during the COVID-19 pandemic. [Extracted from the article]

Objective: We report our experience of functional imaging with 11C-methionine positron emission tomography-computed tomography (PET-CT) co-registered with 3D gradient echo (spoiled gradient recalled (SPGR)) magnetic resonance imaging (MRI) in the investigation of ACTH-dependent Cushing's syndrome. Design: Twenty patients with i) de novo Cushing's disease (CD, n=10), ii) residual or recurrent hypercortisolism following first pituitary surgery (G radiotherapy; n = 8) or iii) ectopic Cushing's syndrome (n = 2) were referred to our centre for functional imaging studies between 2010 and 2015. Six of the patients with de novo CD and five of those with persistent/relapsed disease had a suspected abnormality on conventional MRI. Methods: All patients underwent 11C-methionine PET-CT. For pituitary imaging, co-registration of PET-CT images with contemporaneous SPGR MRI (1 mm slice thickness) was performed, followed by detailed mapping of 11C-methionine uptake across the sella in three planes (coronal, sagittal and axial). This allowed us to determine whether suspected adenomas seen on structural imaging exhibited focal tracer uptake on functional imaging. Results: In seven often patients with de novo CD, asymmetric 11C-methionine uptake was observed within the sella, which co-localized with the suspected site of a corticotroph microadenoma visualised on SPGR MRI (and which was subsequently confirmed histologically following successful transsphenoidal surgery (TSS)). Focal 11C-methionine uptake that correlated with a suspected abnormality on pituitary MRI was seen in five of eight patients with residual or recurrent Cushing's syndrome following first TSS (and pituitary radiotherapy in two cases). Two patients elected to undergo repeat TSS with histology confirming a corticotroph tumour in each case. In two patients with the ectopic ACTH syndrome, 11C-methionine was concentrated in sites of distant metastases, with minimal uptake in the sellar region. Conclusions: 11C-methionine PET-CT can aid the detection of ACTH-secreting tumours in Cushing's syndrome and facilitate targeted therapy. [ABSTRACT FROM AUTHOR]

Background: Recombinant human bone morphogenetic protein-2 (rhBMP-2) is widely used to promote fusion in spinal surgery, but its safety has been questioned.Purpose: To evaluate the effectiveness and safety of rhBMP-2.Data Sources: Individual-participant data obtained from the sponsor or investigators and data extracted from study publications identified by systematic bibliographic searches through June 2012.Study Selection: Randomized, controlled trials of rhBMP-2 versus iliac crest bone graft (ICBG) in spinal fusion surgery for degenerative disc disease and related conditions and observational studies in similar populations for investigation of adverse events.Data Extraction: Individual-participant data from 11 eligible of 17 provided trials sponsored by Medtronic (Minneapolis, Minnesota) (n = 1302) and 1 of 2 other eligible trials (n = 106) were included. Additional aggregate adverse event data were extracted from 35 published observational studies.Data Synthesis: Primary outcomes were pain (assessed with the Oswestry Disability Index [ODI] or Short Form-36), fusion, and adverse events. At 24 months, ODI scores were 3.5% lower (better) with rhBMP-2 than with ICBG (95% CI, 0.5% to 6.5%) and radiographic fusion was 12% higher (CI, 2% to 23%). At or shortly after surgery, pain was more common with rhBMP-2 (odds ratio, 1.78 [CI, 1.06 to 2.95]). Cancer was more common after rhBMP-2 (relative risk, 1.98 [CI, 0.86 to 4.54]), but the small number of events precluded definite conclusions.Limitation: The observational studies were diverse and at risk of bias.Conclusion: At 24 months, rhBMP-2 increases fusion rates, reduces pain by a clinically insignificant amount, and increases early postsurgical pain compared with ICBG. Evidence of increased cancer incidence is inconclusive.Primary Funding Source: Yale University Open Data Access Project. [ABSTRACT FROM AUTHOR]

Background: Recombinant human bone morphogenetic protein-2 (rhBMP-2) is widely used to promote fusion in spinal surgery, but its safety has been questioned. Purpose: To evaluate the effectiveness and safety of rhBMP-2. Data Sources: Individual-participant data obtained from the sponsor or investigators and clata extracted from study publications identified by systematic bibliographic searches through June 2012. Study Selection: Randomized, controlled trials of rhBMP-2 versus lilac crest bone graft (ICBG) in spinal fusion surgery for degenerative disc disease and related conditions and observational studies in similar populations for investigation of adverse events. Data Extraction: Individual-participant data from 11 eligible of 17 provided trials sponsored by Medtronic (Minneapolis, Minnesota) (n = 1302) and 1 of 2 other eligible trials (n = 106) were included. Additional aggregate adverse event data were extracted from 35 published observational studies. Data Synthesis: Primary outcomes were pain (assessed with the Oswestry Disability Index [ODI] or Short Form-36), fusion, and adverse events. At 24 months, ODI scores were 3.5% lower (better) with rhBMP-2 than with ICBG (95% CI, 0.5% to 6.5%) and radiographic fusion was 12% higher (CI, 2% to 23%). At or shortly after surgery, pain was more common with rhBMP-2 (odds ratio, 1.78 [CI, 1.06 to 2.95]). Cancer was more common after rhBMP-2 (relative risk, 1.98 [CI, 0.86 to 4.54]), but the small number of events precluded definite conclusions. Limitation: The observational studies were diverse and at risk of bias. Conclusion: At 24 months, rhBMP-2 increases fusion rates, reduces pain by a clinically insignificant amount, and increases early postsurgical pain compared with ICBG. Evidence of increased cancer incidence is inconclusive. Primary Funding Source: Yale University Open Data Access Project. [ABSTRACT FROM AUTHOR]

Peripheral nerve transection results in the rapid death by apoptosis of neonatal but not adult sensory and motor neurons. We show that this is due to induction and phosphorylation in all adult axotomized neurons of the small heat shock protein Hsp27 and the failure of such induction in most neonatal neurons. In vivo delivery of human Hsp27 but not a nonphosphorylatable mutant prevents neonatal rat motor neurons from nerve injury-induced death, while knockdown in vitro and in vivo of Hsp27 in adult injured sensory neurons results in apoptosis. Hsp27''s neuroprotective action is downstream of cytochrome c release from mitochondria and upstream of caspase-3 activation. Transcriptional and posttranslational regulation of Hsp27 is necessary for sensory and motor neuron survival following peripheral nerve injury. [Copyright &y& Elsevier]

Objectives: The mainstay treatment for Degenerative Cervical Myelopathy (DCM) is surgical decompression. Not all cases, however, are suitable for surgery. Recent international guidelines advise surgery for moderate to severe disease as well as progressive mild disease. The goal of this study was to examine the factors in current practice that drive the decision to operate in DCM. Study design: Retrospective cohort study. Methods: 1 year of cervical spine MRI scans (N = 1123) were reviewed to identify patients with DCM with sufficient clinical documentation (N = 39). Variables at surgical assessment were recorded: age, sex, clinical signs and symptoms of DCM, disease severity, and quantitative MRI measures of cord compression. Bivariate correlations were used to compare each variable with the decision to offer the patient an operation. Subsequent multivariable analysis incorporated all significant bivariate correlations. Results: Of the 39 patients identified, 25 (64%) were offered an operation. The decision to operate was significantly associated with narrower non-pathological canal and cord diameters as well as cord compression ratio, explaining 50% of the variance. In a multivariable model, only cord compression ratio was significant (p = 0.017). Examination findings, symptoms, functional disability, disease severity, disease progression, and demographic factors were all non-significant. Conclusions: Cord compression emerged as the main factor in surgical decision-making prior to the publication of recent guidelines. Newly identified predictors of post-operative outcome were not significantly associated with decision to operate. [ABSTRACT FROM AUTHOR]

We have cloned a second tetrodotoxin-resistant (TTX-R) sodium channel α subunit, SNS2, with the same amino-acid sequence as a putative sodium channel α subunit NaN (ref. 1). SNS2 expression in HEK293T cells produced a TTX-R voltage-gated sodium current with faster kinetics and a lower TTX IC50 than the previously cloned sensory-neuron-specific sodium channel, SNS/PN3 (Refs 2,3). SNS2 was co-expressed with SNS/PN3 in small DRG neurons. [ABSTRACT FROM AUTHOR]

The article summarizes a research study which compared confidential and published clinical trials and adverse event data on the safety and effectiveness of recombinant human bone morphogenetic protein 2 (rhBMP-2) for spinal fusion. An overview of the study participants, setting, design and primary outcomes is provided. Study results are presented including the number of adverse events reported in Medtronic randomized controlled trials collected in individual participant data and publications.