Search

PURPOSE: Primary spinal infections (PSIs) are a group of infectious diseases characterized by inflammation of the end plate-disk unit or its surroundings. PSI is considered more prevalent and aggressive among patients with chronic immunocompromised states. Association of PSIs, immunocompromising cancers, and hemoglobinopathies has not been systematically analyzed. We conducted a systematic review to study characteristics, clinical presentation, and mortality of patients with PSI in the setting of hematologic disease. METHODS: A systematic literature search in PubMed, Web of Science, and Scopus was conducted in April 2022 in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We included retrospective case series and individual case reports. RESULTS: On careful review, 28 articles published between 1970 and 2022 were selected. These studies featured 29 patients who met inclusion criteria (mean age 29 years, age range 1.5 to 67 years; 63.3% male). Lumbar infection was the most common location (65.5%), with Salmonella (24.1%) as the main causative microorganism. Neurologic compromise was present in 41% of patients, and surgical intervention occurred in 48.3%. Average antibiotic duration was 13 weeks. The postoperative complication rate was 21.4%, with a mortality of 6.9%. CONCLUSION: PSI in patients with hematologic disease, while having shorter periods to diagnosis, presents increased rates of neurologic deficit, surgical intervention, and complications.

OBJECTIVE Tranexamic acid (TXA) is an antifibrinolytic agent associated with reduced blood loss and mortality in a wide range of procedures, including spine surgery, traumatic brain injury, and craniosynostosis. Despite this wide use, the safety and efficacy of TXA in spine surgery has been considered controversial due to a relative scarcity of literature and lack of statistical power in reported studies. However, if TXA can be shown to reduce blood loss in laminectomy with fusion and posterior instrumentation, more surgeons may include it in their armamentarium. The authors aimed to conduct an up-to-date systematic review and meta-analysis of the efficacy of TXA in reducing blood loss in laminectomy and fusion with posterior instrumentation. METHODS A systematic review and meta-analysis, abiding by PRISMA guidelines, was performed by searching the databases of PubMed, Web of Science, and Cochrane. These platforms were queried for all studies reporting the use of TXA in laminectomy and fusion with posterior instrumentation. Variables retrieved included patient demographics, surgical indications, involved spinal levels, type of laminectomy performed, TXA administration dose, TXA route of administration, operative duration, blood loss, blood transfusion rate, postoperative hemoglobin level, and perioperative complications. Heterogeneity across studies was evaluated using a chi-square test, Cochran’s Q test, and I2 test performed with R statistical programming software. RESULTS A total of 7 articles were included in the qualitative study, while 6 articles featuring 411 patients underwent statistical analysis. The most common route of administration for TXA was intravenous with 15 mg/kg administered preoperatively. After the beginning of surgery, TXA administration patterns were varied among studies. Blood transfusions were increased in non-TXA cohorts compared to TXA cohorts. Patients administered TXA demonstrated a significant reduction in blood loss (mean difference −218.44 mL; 95% CI −379.34 to −57.53; p = 0.018). TXA administration was not associated with statistically significant reductions in operative durations. There were no adverse events reported in either the TXA or non-TXA patient cohorts. CONCLUSIONS TXA can significantly reduce perioperative blood loss in cervical, thoracic, and lumbar laminectomy and fusion procedures, while demonstrating a minimal complication profile.

OBJECTIVE Elective surgical cases generally have lower costs, higher profit margins, and better outcomes than nonelective cases. Investigating the differences in cost and profit between elective and nonelective cases would help hospitals in planning strategies to withstand financial losses due to potential pandemics. The authors sought to evaluate the exact cost and profit margin differences between elective and nonelective supratentorial tumor resections at a single institution. METHODS The authors collected economic analysis data in all patients who underwent supratentorial tumor resection at their institution between January 2014 and December 2018. The patients were grouped into elective and nonelective cases. Propensity score matching was used to adjust for heterogeneity of baseline characteristics between the two groups. RESULTS There were 143 elective cases and 232 nonelective cases over the 5 years. Patients in the majority of elective cases had private insurance and in the majority of nonelective cases the patients had Medicare/Medicaid (p < 0.01). The total charges were significantly lower for elective cases ($168,800.12) compared to nonelective cases ($254,839.30, p < 0.01). The profit margins were almost 6 times higher for elective than for nonelective cases ($13,025.28 vs $2,128.01, p = 0.04). After propensity score matching, there was still a significant difference between total charges and total cost. CONCLUSIONS Elective supratentorial tumor resections were associated with significantly lower costs with shorter lengths of stay while also being roughly 6 times more profitable than nonelective cases. These findings may help future planning for hospital strategies to survive financial losses during future pandemics that require widespread cancellation of elective cases.

Background Incidental or intentional durotomy in spine surgery is associated with a risk of cerebrospinal fluid (CSF) leakage and reoperation. Several strategies have been introduced, but the incomplete closure is still relatively frequent and troublesome. In this study, we review current evidence on spinal dural repair strategies and evaluate their efficacy. Methods PubMed, Web of Science, and Scopus were used to search primary studies about the repair of the spinal dura with different techniques. Of 265 articles found, 11 studies, which specified repair techniques and postoperative outcomes, were included for qualitative and quantitative analysis. The primary outcomes were CSF leakage and postoperative infection. Results The outcomes of different dural repair techniques were available in 776 cases. Pooled analysis of 11 studies demonstrated that the most commonly used technique was a combination of primary closure, patch or graft, and sealant (22.7%, 176/776). A combination of primary closure and patch or graft resulted in the lowest rate of CSF leakage (5.5%, 7/128). In this study, sealants as an adjunct to primary closure (13.7%, 18/131) did not significantly reduce the rate of CSF leakage compared with primary closure alone (17.6%, 18/102). The rates of infection and postoperative neurologic deficit were similar regardless of the repair techniques. Conclusions Although the use of sealants has become prevalent, available sealants as an adjunct to primary closure did not reduce the rate of CSF leakage compared with primary closure. The combination of primary closure and patches or grafts could be effective in decreasing postoperative CSF leakage.

Background Recently, there has been increased interest in patient satisfaction measures such as Press Ganey and Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) surveys. In this systematic review, the spine surgery literature is analyzed to evaluate factors predictive of patient satisfaction as measured by these surveys. Methods A thorough literature search was performed in PubMed/MEDLINE, Google Scholar, and Cochrane databases. All English-language articles from database inception to July 2020 were screened for study inclusion according to PRISMA guidelines. Results Twenty-four of the 1899 published studies were included for qualitative analysis. There has been a statistically significant increase in the number of publications across years (P = 0.04). Overall, the studies evaluated the relationship between patient satisfaction and patient demographics (71%), preoperative and intraoperative clinical factors (21%), and postoperative factors (33%). Top positive predictors of patient satisfaction were patient and nursing/medical staff relationship (n = 4; 17%), physician–patient relationship (n = 4; 17%), managerial oversight of received care (n = 3; 13%), same sex/ethnicity between patient and physician (n = 2; 8%), and older age (n = 2; 8%). Top negative predictors of patient satisfaction were high Charlson Comorbidity Index/high disability/worse overall health functioning (n = 7; 29%), increased length of hospital stay (n = 4; 17%), high rating for pain/complications/readmissions (n = 4; 17%), and psychosocial factors (n = 3; 13%). Conclusions There is heterogeneity in terms of different factors, both clinical and nonclinically related, that affect patient satisfaction ratings. More research is warranted to investigate the role of hospital consumer surveys in the spine surgical patient population.

Objective A specialty with high value on reliability and accountability, aspiring neurosurgical residents have classically excelled in demonstrating these attributes through in-person engagements. Sub-internship rotations, leadership in extracurriculars, and longitudinal research endeavors have traditionally shed light on uniquely responsible and self-driven candidates. As the COVID-19 pandemic altered the paradigm for medical student engagements, our team investigated whether neurosurgical residency programs would be able to gauge candidates’ favorable attributes with the same accuracy as prior to the pandemic. Design/Setting/Participants: The PubMed/MEDLINE database was queried from inception to 2021 to determine the factors that contribute to a successful American neurosurgery residency match. Inclusion and exclusion criteria were predetermined to ensure comprehensiveness and relevance. Data from the National Residency Matching Program were also reviewed to determine significant trends in the American neurosurgery residency match. These data were then interpreted in the context of the COVID-19 pandemic to gain insight into the present-day neurosurgery match experience. Results A total of 32 studies were included in the review. Factors relevant to current neurosurgery residency match rates include the number of applicants to neurosurgery programs, quantity of research publications, quality of mentorship, interviews, letters of recommendation, standardized academic metrics, and residency program outreach. While current neurosurgery residency program directors are generally satisfied with recent match cycles, survey respondents expressed support for a more objective application review process. The transition to virtual interviews and suspension of away rotations required by the COVID-19 pandemic has raised significant student concerns related to the pandemic’s impact on the current residency recruitment process. Conclusion The neurosurgery match is influenced by multiple dynamic, varied factors that are currently impacted dramatically by the COVID-19 pandemic. While more studies focusing on refining applicant selection processes are warranted, it is imperative for neurosurgical programs to seek new surrogates for assessing favorable neurosurgery residency applicant attributes.

Background: The costs of cervical spine surgery have steadily increased. We performed a 5-year propensity scoring-matched analysis of 276 patients undergoing anterior versus posterior cervical surgery at one institution. Methods: We performed propensity score matching on financial data from 276 patients undergoing 1–3 level anterior versus posterior cervical fusions for degenerative disease (2015–2019). Results: We found no significant difference between anterior versus posterior approaches for hospital costs ($42,529.63 vs. $45,110.52), net revenue ($40,877.25 vs. $34,036.01), or contribution margins ($14,230.19 vs. $6,312.54). Multivariate regression analysis showed variables significantly associated with the lower contribution margins included age (β = −392.3) and length of stay (LOS; β = −1151). Removing age/LOS from the analysis, contribution margins were significantly higher for the anterior versus posterior approach ($17,824.16 vs. $6,312.54, P = 0.01). Conclusion: Anterior cervical surgery produced higher contribution margins compared to posterior approaches, most likely because posterior surgery was typically performed in older patients requiring longer LOS.

External ventricular drainage is a common and invaluable neurosurgical procedure and is one of the first procedures learned and performed independently by neurosurgical residents. As accuracy and precision are paramount to EVD placement, attention to technique is paid early in a resident's training. With the advancement of virtual technology, it has become increasingly possible to move away from traditional training situations and human error, and towards automated assistance and superior cyber learning environments. Although there is significant room for improvement, there are promising results with computerized placement guides and virtually augmented practice. Here, we provide a review of the updates on EVD placement techniques, technology and training, all of which serve to improve the precision, accuracy and efficiency of EVD placement.

We have read with great interest the article by Al Jammal et al. [1] regarding cervical arthroplasty as a treatment for refractory cervical angina and are eager to provide several comments which we believe may be relevant and interesting to your broad readership. In a manner akin to Al Jammal et al. [1], we performed a comprehensive review of the literature regarding cervical angina, also referred to as “pseudoangina,” which has been recently published in Journal of Neurosurgery: Spine [2]. As we describe, pseudoangina pectoris is an underdiagnosed syndrome of radiculopathy which mimics true angina pectoris but is instead the result of spinal pathology (most commonly cervical herniation, which accounted for 72.6% of the 95 patients included in our study).

Background: The aim of this study was to identify patient interest in second opinion services online and identify the options patients have in obtaining second opinions from spine surgeons in the United States. Methods: We utilized Google Trends (i.e., search data since 2010) to ascertain the level of interest in receiving second opinions for spinal surgery. In addition, we contacted the top 30 hospitals for neurology and neurosurgery in the U.S. News rankings by phone to obtain information regarding when/how and at what cost they provide second opinions for spine surgery. Results: The cost of the second surgical opinions averaged $493 (±$343) USD (range $90–$1,300); the time to receive a second opinion averaged 20 (±19) days (range 1 day–5 months). Remote or “online second opinion” programs charged an average of $643 (±$259) USD (range $100–$850), and the time to receive an “online second opinion” averaged 14 (±7) days (range 1–4 weeks). Conclusion: Although second opinions have been shown to be beneficial to patients, ambiguous or high costs and long wait times may serve as barriers for certain groups (i.e., uninsured or underinsured) and potentially diminish the quality of care.

Background: As a growing number of patients seek consultations for increasingly complex and costly spinal surgery, it is of both clinical and economic value to investigate the role for second opinions (SOs). Here, we summarized and focused on the shortcomings of 14 studies regarding the role and value of SOs before proceeding with spine surgery. Methods: Utilizing PubMed, Google Scholar, and Scopus, we identified 14 studies that met the inclusion criteria that included: English, primary articles, and studies published in the past 20 years. Results: We identified the following findings regarding SO for spine surgery: (1) about 40.6% of spine consultations are SO cases; (2) 61.3% of those received a discordant SO; (3) 75% of discordant SOs recommended conservative management; and (4) SO discordance applied to a variety of procedures. Conclusion: The 14 studies reviewed regarding SOs in spine surgery showed that half of the SOs differed from those given in the initial consultation and that SOs in spine surgery can have a substantial impact on patient care. Absent are prospective studies investigating the impact of following a first versus second opinion. These studies are needed to inform the potential benefit of universal implementation of SOs before major spine operations to potentially reduce the frequency and type/extent of surgery.

A long-standing goal of spinal cord injury research is to develop effective repair strategies, which can restore motor and sensory functions to near-normal levels. Recent advances in clinical management of spinal cord injury have significantly improved the prognosis, survival rate and quality of life in patients with spinal cord injury. In addition, a significant progress in basic science research has unraveled the underlying cellular and molecular events of spinal cord injury. Such efforts enabled the development of pharmacologic agents, biomaterials and stem-cell based therapy. Despite these efforts, there is still no standard care to regenerate axons or restore function of silent axons in the injured spinal cord. These challenges led to an increased focus on another therapeutic approach, namely neuromodulation. In multiple animal models of spinal cord injury, epidural electrical stimulation of the spinal cord has demonstrated a recovery of motor function. Emerging evidence regarding the efficacy of epidural electrical stimulation has further expanded the potential of epidural electrical stimulation for treating patients with spinal cord injury. However, most clinical studies were conducted on a very small number of patients with a wide range of spinal cord injury. Thus, subsequent studies are essential to evaluate the therapeutic potential of epidural electrical stimulation for spinal cord injury and to optimize stimulation parameters. Here, we discuss cellular and molecular events that continue to damage the injured spinal cord and impede neurological recovery following spinal cord injury. We also discuss and summarize the animal and human studies that evaluated epidural electrical stimulation in spinal cord injury.

Neuromodulation represents a cutting edge class of both invasive and non-invasive therapeutic methods which alter the activity of neurons. Currently, several different techniques have been developed - or are currently being investigated - to treat a wide variety of neurological and neuropsychiatric disorders. Recently, in vivo and in vitro studies have revealed that neuromodulation can also induce myelination, meaning that it could hold potential as a therapy for various demyelinating diseases including multiple sclerosis and progressive multifocal leukencepalopathy. These findings come on the heels of a paradigm shift in the view of myelin's role within the nervous system from a static structure to an active co-regulator of central nervous system plasticity and participant in neuron-mediated modulation. In the present review, we highlight several of the recent findings regarding the role of neural activity in altering myelination including several soluble and contact-dependent factors that seem to mediate neural activity-dependent myelination. We also highlight several considerations for neuromodulatory techniques, including the need for further research into spatiotemporal precision, dosage, and the safety and efficacy of transcranial focused ultrasound stimulation, an emerging neuromodulation technology. As the field of neuromodulation continues to evolve, it could potentially bring forth methods for the treatment of demyelinating diseases, and as such, further investigation into the mechanisms of neuron-dependent myelination as well as neuro-imaging modalities that can monitor myelination activity is warranted.

OBJECTIVEMinimally invasive anterior lumbar interbody fusion surgery (MIS ALIF) is a technique that restores disc height and lumbar lordosis through a smaller exposure and less soft-tissue trauma compared to open approaches. The mini-open and laparoscopic assistance techniques are two main forms of MIS ALIF. The authors conducted a systematic review that sought to critically summarize the literature on back pain following MIS ALIF.METHODSIn March 2020, the authors searched the PubMed, Web of Science, and Cochrane Library databases for studies describing back pain visual analog scale (VAS) outcomes after MIS ALIF. The following exclusion criteria were applied to studies evaluated in full text: 1) the study included fewer than 20 patients, 2) the mean follow-up duration was shorter than 12 months, 3) the study did not report back pain VAS score as an outcome measure, and 4) MIS ALIF was not studied specifically. The methodology for the included studies were evaluated for potential biases and assigned a level of evidence.RESULTSThere were a total of 552 patients included from 13 studies. The most common biases were selection and interviewer bias. The majority of studies were retrospective. The mean sample size was 42.3 patients. The mean follow-up duration was approximately 41.8 months. The mean postoperative VAS reduction was 5.1 points. The mean VAS reduction for standalone grafts was 5.9 points, and 5.0 points for those augmented with posterior fixation. The most common complications included bladder or urinary dysfunction, infection, and hardware-related complications.CONCLUSIONSThis was a systematic review of back pain outcomes following MIS ALIF. Back pain VAS score was reduced postoperatively across all studies. The complication rates were low overall. MIS ALIF is safe and effective at reducing back pain in appropriate patient populations.

The mechanisms of appetite disorders, such as refractory obesity and anorexia nervosa, have been vigorously studied over the last century, and these studies have shown that the central nervous system has significant involvement with, and responsibility for, the pathology associated with these diseases. Because deep brain stimulation has been shown to be a safe, efficacious, and adjustable treatment modality for a variety of other neurological disorders, it has also been studied as a possible treatment for appetite disorders. In studies of refractory obesity in animal models, the ventromedial hypothalamus, the lateral hypothalamus, and the nucleus accumbens have all demonstrated elements of success as deep brain stimulation targets. Multiple targets for deep brain stimulation have been proposed for anorexia nervosa, with research predominantly focusing on the subcallosal cingulate, the nucleus accumbens, and the stria terminalis and medial forebrain bundle. Human deep brain stimulation studies that focus specifically on refractory obesity and anorexia nervosa have been performed but with limited numbers of patients. In these studies, the target for refractory obesity has been the lateral hypothalamus, ventromedial hypothalamus, and nucleus accumbens, and the target for anorexia nervosa has been the subcallosal cingulate. These studies have shown promising findings, but further research is needed to elucidate the long-term efficacy of deep brain stimulation for the treatment of appetite disorders.

Objective Obesity has become a worldwide epidemic, with very few long-term successful treatment options for refractory disease. Deep brain stimulation (DBS) of the bilateral lateral hypothalamus (LH) in refractory obesity has been performed safely. However, questions remain regarding the optimal settings and its effects on metabolic rate. The goals of our experiment were to determine the optimal DBS settings and the actual effect of optimal stimulation on energy expenditure. Methods After bilateral LH DBS implantation, 2 subjects with treatment refractory obesity underwent 4 days of metabolic testing. The subjects slept overnight in a respiratory chamber to measure their baseline sleep energy expenditure, followed by 4 consecutive days of resting metabolic rate (RMR) testing at different stimulation settings. On day 4, the optimized DBS settings were used, and sleep energy expenditure was measured again overnight in the room calorimeter. Results During daily testing, the RMR fluctuated acutely with changes in stimulation settings and returned to baseline immediately after turning off the stimulation. Optimal stimulation settings selected for participants showed a 20% and 16% increase in RMR for the 2 participants. Overnight sleep energy expenditure measurements at these optimized settings on day 4 yielded a 10.4% and 4.8% increase over the baseline measurements for the 2 participants. Conclusions These findings have demonstrated the efficacy of optimized DBS of the LH on increasing the RMR acutely and maintaining this increase during overnight sleep. These promising preliminary findings have laid the groundwork for the possible treatment of refractory obesity with DBS.

Background Interbody fusion cages with integrated fixation components have become of interest due to their ability to provide enhanced post-operative stability and mitigate device migration. A recently approved anterior lumbar interbody fusion cage with integrated fixation anchors has yet to be compared in vitro to a standard polyetheretherketone cage when used in combination with an interspinous process clamp. Methods Twelve human cadaveric lumbar segments were implanted at L4–L5 with a Solus interbody cage (n = 6) or standard polyetheretherketone cage (n = 6) following Intact testing and discectomy. Each cage was subsequently evaluated in all primary modes of loading after supplementation with the following posterior constructs: interspinous process clamp, bilateral transfacet screws, unilateral transfacet screw with contralateral pedicle screws, and bilateral pedicle screws. Range of motion results were normalized to Intact, and a two-way mixed analysis of variance was utilized to detect statistical differences. Findings The Solus cage in combination with all posterior constructs provided significant fixation compared to Intact in all loading conditions. The polyetheretherketone cage also provided significant fixation when combined with all screw based treatments, however when used with the interspinous process clamp a significant reduction was not observed in lateral bending or axial torsion. Interpretation Interbody cages with integrated fixation components enhance post-operative stability within the intervertebral space, thus affording clinicians the potential to utilize less invasive methods of posterior stabilization when seeking circumferential fusion. Interspinous process clamps, in particular, may reduce peri-operative and post-operative comorbidities compared to screw based constructs. Further study is necessary to corroborate their effectiveness in vivo .

Object Deep brain stimulation (DBS) of the lateral hypothalamic area (LHA) has been suggested as a potential treatment for intractable obesity. The authors present the 2-year safety results as well as early efficacy and metabolic effects in 3 patients undergoing bilateral LHA DBS in the first study of this approach in humans. Methods Three patients meeting strict criteria for intractable obesity, including failed bariatric surgery, underwent bilateral implantation of LHA DBS electrodes as part of an institutional review board– and FDA-approved pilot study. The primary focus of the study was safety; however, the authors also received approval to collect data on early efficacy including weight change and energy metabolism. Results No serious adverse effects, including detrimental psychological consequences, were observed with continuous LHA DBS after a mean follow-up of 35 months (range 30–39 months). Three-dimensional nonlinear transformation of postoperative imaging superimposed onto brain atlas anatomy was used to confirm and study DBS contact proximity to the LHA. No significant weight loss trends were seen when DBS was programmed using standard settings derived from movement disorder DBS surgery. However, promising weight loss trends have been observed when monopolar DBS stimulation has been applied via specific contacts found to increase the resting metabolic rate measured in a respiratory chamber. Conclusions Deep brain stimulation of the LHA may be applied safely to humans with intractable obesity. Early evidence for some weight loss under metabolically optimized settings provides the first “proof of principle” for this novel antiobesity strategy. A larger follow-up study focused on efficacy along with a more rigorous metabolic analysis is planned to further explore the benefits and therapeutic mechanism behind this investigational therapy.

Background: Deep brain stimulation (DBS) has emerged in recent years as a novel therapy in the treatment of refractory psychiatric disease, including major depressive disorder (MDD), obsessive-compulsive disorder (OCD), and Tourette's syndrome (TS). Standardized outcome scales were crucial in establishing that DBS was an effective therapy for movement disorders. Objective: In order to better characterize the evidence supporting DBS for various psychiatric diseases, we performed a pooled analysis of those studies which incorporated specific standardized rating scales. Methods: A Medline search was conducted to identify all studies reporting DBS for MDD, OCD, and TS. The search yielded a total of 49 articles, of which 24 were included: 4 related to MDD (n = 48), 10 to OCD (n = 64), and 10 to TS (n = 46). Results: A meta-analysis of DBS for MDD, OCD, and TS in studies employing disease-specific standardized outcome scales showed that the outcome scales all improved in a statistically significant fashion for these psychiatric diseases. Our pooled analysis suggests that DBS for TS has the highest efficacy amongst the psychiatric diseases currently being treated with DBS, followed by OCD and MDD. Conclusion: DBS for psychiatric diseases remains investigational; however, even when studies failing to incorporate standardized outcome scales are excluded, there is statistically significant evidence that DBS can improve symptoms in MDD, OCD, and TS. Standardized disease-specific outcome scales facilitate pooled analysis and should be a required metric in future studies of DBS for psychiatric disease.

OBJECTIVE Spinal stability is attributed in part to osteoligamentous structures, including the vertebral body, facets, intervertebral discs, and posterior elements. The materials in this study provide an opportunity to augment the degenerated nucleus without removing native disc material, a procedure introduced here as “fortification.” The objective of this study was to determine the effect of nucleus fortification on lumbar disc biomechanics. METHODS The authors performed in vitro analysis of human cadaveric functional spinal units (FSUs), along with characterization and quantification of movement of the units using biomechanical data in intact, disc-only, and fortified specimens. The units underwent removal of all posterior elements and annulus and were fortified by injecting a biogel into the nucleus pulposus. Each specimen was subjected to load testing, range of motion (ROM) quantification, and disc bulge measurements. Optoelectric tracking was used to quantify disc bulge. These criteria were assessed in the intact, disc-only, and fortified treatments. RESULTS Disc-only FSUs resulted in increased ROM when compared with intact and fortified conditions. Fortification of the FSU resulted in partial restoration of normal ROM in the treatment groups. Analysis of hysteresis loops showed more linear response in the fortified groups when compared with the intact and disc-only groups. CONCLUSIONS Disc nucleus fortification increases linearity and decreases ROM.

Obesity remains a pervasive global health problem. While there are a number of nonsurgical and surgical options for treatment, the incidence of obesity continues to increase at an alarming rate. The inability to curtail the growing rise of the obesity epidemic may be related to a combination of increased food availability and palatability. Research into feeding behavior has yielded a number of insights into the homeostatic and reward mechanisms that govern feeding. However, there remains a gap between laboratory investigations of feeding physiology in animals and translation into meaningful treatment options for humans. In addition, laboratory investigation may not be able to recapitulate all aspects of human food consumption. In a landmark pilot study of deep brain stimulation (DBS) of the lateral hypothalamic area for obesity, we found that there was an increase in resting metabolic rate as well as a decreased urge to eat. In this review, the authors will review some of the work relating to feeding physiology and research surrounding two nodes involved in feeding homeostasis, nucleus accumbens (NAc) and hypothalamus, and use this to provide a framework for future investigations of DBS as a viable therapeutic modality for obesity.

Obesity is perhaps an evolutionary consequence of a species reared with intermittent caloric reward. Humans are hardwired to enjoy food, and our bodies voraciously extract and store energy from food as if each meal was the last. As an amalgam of behavioral and metabolic disturbance, obesity is an attractive target for deep brain stimulation (DBS) since neuromodulation may be able to influence both eating behavior and metabolism. The current pandemic proportions of obesity combined with the failures and morbidity of modern treatments remain the impetus behind the application of DBS to this complex disease. We review the rationale and scientific foundations for obesity DBS and explain how this preclinical evidence has helped sculpt the design of the first human pilot study.

The indications for deep brain stimulation (DBS) are expanding, and the feasibility and efficacy of this surgical procedure in various neurologic and neuropsychiatric disorders continue to be tested. This review attempts to provide background and rationale for applying this therapeutic option to obesity and addiction. We review neural targets currently under clinical investigation for DBS—the hypothalamus and nucleus accumbens—in conditions such as cluster headache and obsessive-compulsive disorder. These brain regions have also been strongly implicated in obesity and addiction. These disorders are frequently refractory, with very high rates of weight regain or relapse, respectively, despite the best available treatments. We performed a structured literature review of the animal studies of DBS, which revealed attenuation of food intake, increased metabolism, or decreased drug seeking. We also review the available radiologic evidence in humans, implicating the hypothalamus and nucleus in obesity and addiction. The available evidence of the promise of DBS in these conditions combined with significant medical need, support pursuing pilot studies and clinical trials of DBS in order to decrease the risk of dietary and drug relapse. Well-designed pilot studies and clinical trials enrolling carefully selected patients with obesity or addiction should be initiated.

Major contributions to the understanding of human brain function have come from detailed clinical reports of responses evoked by electrical stimulation and specific brain regions during neurosurgical procedures in awake humans. In this study, microstimulation evoked responses and extracellular unit recordings were obtained intraoperatively in 3 awake patients undergoing bilateral implantation of deep brain stimulation electrodes in the lateral hypothalamus. The microstimulation evoked responses exhibited a clear anatomical distribution. Anxiety was most reliably evoked by stimulation directed ventromedially within or adjacent to the ventromedial nucleus of the hypothalamus, nausea was most reliably evoked by stimulation directed at the center of the lateral hypothalamus, and paresthesias were most reliably evoked by stimulation at the border of the lateral hypothalamus and basal nuclei. Regarding the unit recordings, the firing rates of individual neurons did not have an anatomical distribution, but a small subpopulation of neurons located at the border of the lateral hypothalamus and basal nuclei exhibited a fast rhythmically bursting behavior with an intraburst frequency of 200–400 Hz and an interburst frequency of 10–20 Hz. Based on animal studies, the lateral hypothalamic area and surrounding hypothalamic nuclei are putatively involved with a variety of physiological, behavioral, and sensory functions. The lateral hypothalamus is situated to play a dynamic and complex role in human behavior and this report further shows that to be true. In addition, this report should serve as a valuable resource for future intracranial work in which accurate targeting within this region is required.

Panic attacks are sudden debilitating attacks of intense distress often accompanied by physical symptoms such as shortness of breath and heart palpitations. Numerous brain regions, hormones, and neurotransmitter systems are putatively involved, but the etiology and neurocircuitry of panic attacks is far from established. One particular brain region of interest is the ventromedial hypothalamus (VMH). In cats and rats, electrical stimulation delivered to the VMH has been shown to evoke an emotional “panic attack–like” escape behavior, and in humans, stimulation targeting nuclei just posterior or anterior to the VMH has reportedly induced panic attacks. The authors report findings obtained in an awake patient undergoing bilateral implantation of deep brain stimulation electrodes into the hypothalamus that strongly implicates the VMH as being critically involved in the genesis of panic attacks. First, as the stimulating electrode progressed deeper into the VMH, the intensity of stimulation required to evoke an attack systematically decreased; second, while stimulation of the VMH in either hemisphere evoked panic, stimulation that appeared to be in the center of the VMH was more potent. Thus, this evidence supports the role of the VMH in the induction of panic attacks purported by animal studies.

Object Deep brain stimulation (DBS) of the ventral intermediate nucleus of the thalamus (VIM) has proven to be efficacious in the treatment of essential tremor (ET). The authors report on long-term follow-up of a series of patients treated at 1 institution by 1 neurosurgeon. Methods Thirty-four patients with ET received unilateral or bilateral VIM DBS. The tremor and handwriting components of the Fahn-Tolosa-Marin clinical tremor rating scale were assessed pre- and postoperatively. Visual analog scale scores for overall patient satisfaction and tremor control were recorded. Stimulation parameters at different intervals after surgery were also recorded. Results The average follow-up period was 56.9 months. The average tremor score improved from 3.27 preoperatively to 0.64 postoperatively (on stimulation; p < 0.001) and the average handwriting score improved from 2.94 to 0.89 (p < 0.001). The average visual analog scale score for overall satisfaction was 8.12 and for tremor control was 1.43. Overall, there was an 80.4% improvement in tremor and 69.7% improvement in handwriting. In 12 patients both tremor and handwriting scores were compared between 57.3 months and 90.7 months after surgery and no significant changes were discovered. Comparison of stimulation parameters at onset and at 1–3, 3–5, 5–7, and > 7 years after surgery showed significant differences, with a gradual increase in stimulation parameters within 5 years after surgery. The overall hardware-related complication rate was 23.5%. Conclusions Deep brain stimulation of the VIM is an efficient and safe treatment for ET. Tremor and handwriting improvements in long-term follow-up are stable. The patients' perception of their outcome is quite good. However, tolerance may develop in some patients requiring changes in stimulation parameters.

Over the past 50 years, various shunting procedures involving the peritoneum have been performed for the treatment of hydrocephalus. During placement of the peritoneal portion of the catheter, complications may arise secondary to a lack of direct visualization. We describe a reduced complication rate with laparoscopically-assisted placement of the peritoneal portion of the catheter. A retrospective chart review was performed of seventy-six (76) laparoscopically-assisted cases performed without consideration of prior abdominal surgery or obesity. Subjects ranged in age from 19 to 80 years. Mean operative time was 55.3 minutes. No visceral injuries occurred. To date, no infectious complications have occurred. In 3% of subjects, conversion to an open procedure was necessary after failure to establish pneumoperitoneum. Laparoscopic placement of peritoneal shunts is safe and efficacious. It provides visualization of the distal catheter target. Moreover, it reduces the risk of visceral complications, CSF pseudocysts, or extraperitoneal placement of the catheter. In the future, laparoscopic placement of the peritoneal portion of the catheter may become a standard treatment in those patients requiring placement of a peritoneal catheter.

The objective of the study was to determine if negative multidetector computed tomography (MDCT) and lateral radiography of the cervical spine effectively excludes patients with unstable cervical spine injuries. Over a period of 40 months, 6558 people were admitted to our trauma service with blunt injury and 447 (6.8%) were found to have cervical fractures. Fractures were identified by CT and/or lateral radiography. In order to rule out clinically significant instability in the absence of fracture, we identified nine patients who required any type of stabilization of the cervical spine including anterior fusion, posterior fusion and external orthosis. These patients also underwent MR of the cervical spine. Radiography, CT, and MR images and reports of these nine patients were reviewed. Nine patients without a fracture required cervical stabilization. These patients had the following abnormalities: disc herniation with canal stenosis in three, unilateral jumped facet in three, and various other soft tissue abnormalities in three, all of which were evident on CT or radiography. All nine patients had evidence for cervical spine injury or instability by MDCT. Normal MDCT and radiography appears adequate to 'clear' the cervical spine. We recommend that patients requiring cervical spine clearance undergo a complete MDCT and lateral radiograph of the cervical spine. If these studies are entirely normal, then the cervical spine may be cleared. If any abnormalities, including disc herniation, soft tissue swelling and bony malalignments are noted by radiography and/or MDCT, further studies, including MR, are indicated prior to clearance of the cervical spine.

Ventriculostomy is a common practice in neurosurgery, but the annual trend of this procedure in the United States has not been reported in the literature. This study evaluates the annual trend during a recent 5-year period. Between 1997 and 2001, a retrospective review was undertaken concerning all patients in the Nationwide Inpatient Sample (NIS) who had undergone ventriculostomy. The population sample represented approximately a 20% stratified sample of nonfederal hospitals in the United States. The annual number of patients who underwent ventriculostomy during the study period ranged from 20,586 to 25,634. Most patients were male (53.4%), with a mean age of 44.8 years, were commercially insured (46.0%) and had a median annual income above $25,000 (84.4%). Most frequent ICD-9-CM diagnoses were subarachnoid haemorrhage, intracerebral haemorrhage and obstructive hydrocephalus, respectively. The majority of ventriculostomies were performed in large, private, not-for-profit, metropolitan, teaching institutions. Mean length of hospital stay was 19.2 days. Regarding discharge status for patients who had undergone ventriculostomy, approximately one-quarter died in the hospital, one-third were discharged home and one-third were transferred to another institution. No demographic variables changed during the study with the exception of location of ventriculostomy in a teaching hospital, which increased from 64.4% in 1997 to 77.4% in 2001. Patient and hospital demographic characteristics were consistent during the study period. By extrapolation of the data, the prevalence of ventriculostomy in the United States averaged 24,380 per year. This study is the first to comprehensively document data concerning the epidemiology of this common procedure.

Background The influence of interbody cage positioning on clinical outcomes following lumbar interbody fusion is not well understood, though it has been hypothesized to play a significant role in stability of the treated level. The purpose of this study was to evaluate any correlations between cage placement in TLIF procedures and post-operative kinematics. Methods Thirteen patients who had previously undergone a TLIF procedure were evaluated using the Vertebral Motion Analysis (VMA) system, an automated fluoroscopic method of tracking kinematics in vivo. Upright and recumbent bending platforms were used to guide patients through a set range of motion (ROM) standing up and lying down, respectively, in both flexion-extension (FE) and lateral bending (LB). Intervertebral ROM was measured via fluoroscopic images captured sequentially throughout the movement. DICOM images acquired by the VMA system were used to calculate cage positioning. Intra-rater and inter-rater reliability of TLIF cage position were also assessed. Results Statistically significant correlations were noted between sagittal cage position and lying LB (r = -0.583, p = 0.047), and coronal cage positioning with both standing (r = 0.672, p = 0.012) and lying LB (r = 0.632, p = 0.027). Additionally, the correlation between sagittal cage position and standing FE was trending towards significance (r = -0.542, p = 0.055). Conclusions The intuitive correlation between coronal cage position and both standing and lying lateral bending ROM is supported by the data from this study, suggesting placement closer to midline is optimal for stability. Additionally, the VMA system appears to be a sensitive and repeatable means to obtain information on postoperative kinematic outcomes. Further work to establish the relationship between cage placement, these kinematic outcomes and, potentially, functional pain outcomes seems to be warranted based on the results obtained here.

The authors review the history of deep brain stimulation (DBS) in patients for treating obesity, describe current DBS targets in the brain, and discuss potential DBS targets and nontraditional stimulation parameters that may improve the effectiveness of DBS for ameliorating obesity. Deep brain stimulation for treating obesity has been performed both in animals and in humans with intriguing preliminary results. The brain is an attractive target for addressing obesity because modulating brain activity may permit influencing both sides of the energy equation—caloric intake and energy expenditure.

BACKGROUND The efficacy of intrafacet bone dowels in promoting lumbar fusion has not been established. A recently published study indicates a low fusion rate, along with device migration. OBJECTIVE To evaluate the mechanical stability of 2 lumbar facet fixation technologies before and after repeated cyclic loading. METHODS Six human lumbar specimens were implanted with both types of allograft, one at L2-3 and the other at L4-5, on a randomized basis. All specimens were subjected to pure-moment flexibility testing before and after implantation and after 2500 and 5000 cycles of flexion-extension bending. Each specimen was scanned with computed tomography before and after cyclic loading to measure device migration. RESULTS Only dowel 1 resulted in a statistically significant reduction in flexion-extension range of motion at the treatment level. This reduction was significant at baseline testing (P = .03) and after 2500 cycles of flexion-extension loading (P = .048) but was not significant after 5000 cycles of loading. One of the bone dowels extruded posteriorly out of the joint space during baseline axial torsion flexibility testing, which was before any cyclic loading. CONCLUSION The data obtained in this study do not indicate efficacy of fixation for cylindrical bone dowels in the lumbar facet joint. Significant fixation was detected only for one of the devices and was no longer present after a relatively short duration of repeated loading. Furthermore, considerable magnitudes of device migration were detected.

In this article we will discuss the treatment of Occipital Neuralgia (ON) and Transformed Migraine (TM) using a paddle style surgical stimulator lead. A paddle style electrode may have advantages to the cylindrical style in reducing migrations from cervical tension or anchor dislodgement. It should be considered in refractory "neuropathic" cervicocranial syndromes such as ON and TM before moving on to more aggressive surgical interventions.

BACKGROUND Lead migration is a frequent complication of spinal cord stimulation (SCS) and requires revision surgery. The evolution of wider paddle leads has necessitated more extensive laminotomy and epidural adhesiolysis, which may increase the risk of lead migration. OBJECTIVE We describe a novel anchoring technique for SCS paddle leads with use of a cranial "dogbone" plate. METHODS We retrospectively reviewed a consecutive series of 11 patients who underwent placement of paddle lead spinal cord stimulators with titanium plate anchoring. Patients were followed for a mean of 29.5 months from SCS implantation (range, 5-65 months). A 4-hole linear titanium cranial plate and two 4-mm screws were used to tightly affix the proximal paddle lead wiring to the lamina below the laminotomy defect. RESULTS All patients continue to have satisfactory spinal cord stimulation with no loss of efficacy or need for revision. No complications have been attributed to titanium plate anchoring, and there have been no cases of lead migration with this technique. Titanium plate anchoring added minimal time (approximately 3-5 minutes) to the operative case. CONCLUSION We report a safe and effective anchoring technique for paddle lead SCS with the use of a cranial plate. Our experience has been that this technique, which anchors the proximal lead wiring to the remaining lamina at the inferior laminotomy defect, is superior to anchoring methods that rely on suturing of lead wiring.

OBJECTIVE Patients with chronically implanted deep brain stimulator (DBS) electrodes can encounter complications requiring hardware removal. We assessed the safety and efficacy of using implanted DBS electrodes to create a therapeutic lesion before their removal. METHODS Revision or removal of the DBS electrodes was required in two patients who had previously undergone DBS implantation. We conducted a series of in vitro experiments to confirm that the DBS electrodes could be used to generate radiofrequency lesions and to assess the relationship between radiofrequency parameters and lesion size. With this information, and with the approval of the hospital ethical review board, implanted electrodes were used to create incremental radiofrequency lesions in the thalamus in one patient and in the subthalamic nucleus in another. The procedures were performed under local anesthesia with contiguous contacts of the DBS lead connected to the active and reference sites of the RF generator to create a bipolar lesion. RESULTS A 51-year-old man with essential tremor and a thalamic DBS required repeated battery changes secondary to tolerance and high voltage demands. Rather than replacing the battery, a radiofrequency thalamotomy was performed by using the existing left DBS electrode. At the 6-month follow-up examination, successful lesioning provided near complete tremor control. A second patient, a 50-year-old man with Parkinson's disease who had undergone bilateral subthalamic deep brain stimulation, developed skin erosion over the DBS hardware. A subthalamic nucleus lesion was made through the right DBS electrode. Lesion position and size were confirmed with magnetic resonance imaging. CONCLUSION Lesions can be made through chronically implanted DBS electrodes in a safe, graded fashion and can produce therapeutic benefit.