Timing-dependent synergies between motor cortex and posterior spinal stimulation in humans.

Volitional movement requires descending input from the motor cortex and sensory feedback through the spinal cord. We previously developed a paired brain and spinal electrical stimulation approach in rats that relies on convergence of the descending motor and spinal sensory stimuli in the cervical cord. This approach strengthened sensorimotor circuits and improved volitional movement through associative plasticity. In humans, it is not known whether posterior epidural spinal cord stimulation targeted at the sensorimotor interface or anterior epidural spinal cord stimulation targeted within the motor system is effective at facilitating brain evoked responses. In 59 individuals undergoing elective cervical spine decompression surgery, the motor cortex was stimulated with scalp electrodes and the spinal cord was stimulated with epidural electrodes, with muscle responses being recorded in arm and leg muscles. Spinal electrodes were placed either posteriorly or anteriorly, and the interval between cortex and spinal cord stimulation was varied. Pairing stimulation between the motor cortex and spinal sensory (posterior) but not spinal motor (anterior) stimulation produced motor evoked potentials that were over five times larger than brain stimulation alone. This strong augmentation occurred only when descending motor and spinal afferent stimuli were timed to converge in the spinal cord. Paired stimulation also increased the selectivity of muscle responses relative to unpaired brain or spinal cord stimulation. Finally, clinical signs suggest that facilitation was observed in both injured and uninjured segments of the spinal cord. The large effect size of this paired stimulation makes it a promising candidate for therapeutic neuromodulation. KEY POINTS: Pairs of stimuli designed to alter nervous system function typically target the motor system, or one targets the sensory system and the other targets the motor system for convergence in cortex. In humans undergoing clinically indicated surgery, we tested paired brain and spinal cord stimulation that we developed in rats aiming to target sensorimotor convergence in the cervical cord. Arm and hand muscle responses to paired sensorimotor stimulation were more than five times larger than brain or spinal cord stimulation alone when applied to the posterior but not anterior spinal cord. Arm and hand muscle responses to paired stimulation were more selective for targeted muscles than the brain- or spinal-only conditions, especially at latencies that produced the strongest effects of paired stimulation. Measures of clinical evidence of compression were only weakly related to the paired stimulation effect, suggesting that it could be applied as therapy in people affected by disorders of the central nervous system.

Intraoperative electrical stimulation of the human dorsal spinal cord reveals a map of arm and hand muscle responses.

Although epidural stimulation of the lumbar spinal cord has emerged as a powerful modality for recovery of movement, how it should be targeted to the cervical spinal cord to activate arm and hand muscles is not well understood, particularly in humans. We sought to map muscle responses to posterior epidural cervical spinal cord stimulation in humans. We hypothesized that lateral stimulation over the dorsal root entry zone would be most effective and responses would be strongest in the muscles innervated by the stimulated segment. Twenty-six people undergoing clinically indicated cervical spine surgery consented to mapping of motor responses. During surgery, stimulation was performed in midline and lateral positions at multiple exposed segments; six arm and three leg muscles were recorded on each side of the body. Across all segments and muscles tested, lateral stimulation produced stronger muscle responses than midline despite similar latency and shape of responses. Muscles innervated at a cervical segment had the largest responses from stimulation at that segment, but responses were also observed in muscles innervated at other cervical segments and in leg muscles. The cervical responses were clustered in rostral (C4-C6) and caudal (C7-T1) cervical segments. Strong responses to lateral stimulation are likely due to the proximity of stimulation to afferent axons. Small changes in response sizes to stimulation of adjacent cervical segments argue for local circuit integration, and distant muscle responses suggest activation of long propriospinal connections. This map can help guide cervical stimulation to improve arm and hand function.NEW & NOTEWORTHY A map of muscle responses to cervical epidural stimulation during clinically indicated surgery revealed strongest activation when stimulating laterally compared to midline and revealed differences to be weaker than expected across different segments. In contrast, waveform shapes and latencies were most similar when stimulating midline and laterally, indicating activation of overlapping circuitry. Thus, a map of the cervical spinal cord reveals organization and may help guide stimulation to activate arm and hand muscles strongly and selectively.

Decompression alone versus decompression with fusion in patients with lumbar spinal stenosis with degenerative spondylolisthesis: a systematic review and meta-analysis.

INTRODUCTION: Surgical decompression is standard care in the treatment of degenerative spondylolisthesis in patients with symptomatic lumbar spinal stenosis, but there remains controversy over the benefits of adding fusion. The persistent lack of consensus on this matter and the availability of new data warrants a contemporary systematic review and meta-analysis of the literature. METHODS: Multiple online databases were systematically searched up to October 2022 for randomized controlled trials (RCTs) and prospective studies comparing outcomes of decompression alone versus decompression with fusion for lumbar spinal stenosis in patients with degenerative spondylolisthesis. Primary outcome was the Oswestry Disability Index. Secondary outcomes included leg and back pain, surgical outcomes, and radiological outcomes. Pooled effect estimates were calculated and presented as mean differences (MD) with their 95% confidence intervals (CI) at two-year follow-up. RESULTS: Of the identified 2403 studies, eventually five RCTs and two prospective studies were included. Overall, most studies had a low or unclear risk of selection bias and most studies were focused on low grade degenerative spondylolisthesis. All patient-reported outcomes showed low statistical heterogeneity. Overall, there was high-quality evidence suggesting no difference in functionality at two years of follow-up (MD - 0.31, 95% CI - 3.81 to 3.19). Furthermore, there was high-quality evidence of no difference in leg pain (MD - 1.79, 95% CI - 5.08 to 1.50) or back pain (MD - 2.54, 95% CI - 6.76 to 1.67) between patients undergoing decompression vs. decompression with fusion. Pooled surgical outcomes showed less blood loss after decompression only, shorter length of hospital stay, and a similar reoperation rate compared to decompression with fusion. CONCLUSION: Based on the current literature, there is high-quality evidence of no difference in functionality after decompression alone compared to decompression with fusion in patients with degenerative lumbar spondylolisthesis at 2 years of follow-up. Further studies should focus on long-term comparative outcomes, health economic evaluations, and identifying those patients that may benefit more from decompression with fusion instead of decompression alone. This review was registered at Prospero (CRD42021291603).

Feasibility of smart glasses in supporting spinal surgical procedures in low- and middle-income countries: experiences from East Africa.

OBJECTIVE: Telemedicine technology has been developed to allow surgeons in countries with limited resources to access expert technical guidance during surgical procedures. The authors report their initial experience using state-of-the-art wearable smart glasses with wireless capability to transmit intraoperative video content during spine surgery from sub-Saharan Africa to experts in the US. METHODS: A novel smart glasses system with integrated camera and microphone was worn by a spine surgeon in Dar es Salaam, Tanzania, during 3 scoliosis correction surgeries. The images were transmitted wirelessly through a compatible software system to a computer viewed by a group of fellowship-trained spine surgeons in New York City. Visual clarity was determined using a modified Snellen chart, and a percentage score was determined on the smallest line that could be read from the 8-line chart on white and black backgrounds. A 1- to 5-point scale (from 1 = unrecognizable to 5 = optimal clarity) was used to score other visual metrics assessed using a color test card including hue, contrast, and brightness. The same scoring system was used by the group to reach a consensus on visual quality of 3 intraoperative points including instruments, radiographs (ability to see pedicle screws relative to bony anatomy), and intraoperative surgical field (ability to identify bony landmarks such as transverse processes, pedicle screw starting point, laminar edge). RESULTS: All surgeries accomplished the defined goals safely with no intraoperative complications. The average download and upload connection speeds achieved in Dar es Salaam were 45.21 and 58.89 Mbps, respectively. Visual clarity with the modified white and black Snellen chart was 70.8% and 62.5%, respectively. The average scores for hue, contrast, and brightness were 2.67, 3.33, and 2.67, respectively. Visualization quality of instruments, radiographs, and intraoperative surgical field were 3.67, 1, and 1, respectively. CONCLUSIONS: Application of smart glasses for telemedicine offers a promising tool for surgical education and remote training, especially in low- and middle-income countries. However, this study highlights some limitations of this technology, including optical resolution, intraoperative lighting, and internet connection challenges. With continued collaboration between clinicians and industry, future iterations of smart glasses technology will need to address these issues to stimulate robust clinical utilization.

Multilevel anterior cervical osteotomies with uncinatectomies to correct a fixed kyphotic deformity associated with ankylosing spondylitis: technical note and operative video.

Ankylosing spondylitis (AS) is an inflammatory disorder leading to ossification of joints and ligaments, resulting in autofusion throughout the spinal column. In patients with fixed, kyphotic cervical deformities, which cause an impaired horizontal gaze and severe neck pain, surgical intervention is warranted. Although several articles have described the anterior and/or posterior surgical treatments used to address the fixed kyphosis, few sources present the key operative steps and technical nuances. The purpose of this technical report was to provide detailed surgical steps, representative photographs, and an operative video demonstrating multilevel anterior cervical osteotomies, uncinatectomies, and a posterior osteotomy for the correction of a fixed cervical deformity secondary to AS.

Comparison of pain outcomes between two anti-GD2 antibodies in patients with neuroblastoma.

BACKGROUND: Addition of anti-GD2 antibody ch14.18 to the treatment of neuroblastoma has improved outcomes. The most common side effect of ch14.18 is neuropathic pain, which may in part be complement-mediated. Hu14.18K322A is a humanized anti-GD2 antibody designed to diminish complement activation and induce less pain. We compare the pain outcomes in patients treated with ch14.18 and those treated with hu14.18K322A, and explore dose-dependent relationships between pain scores, opioid requirements, and complement levels in patients treated with hu14.18K322A. PROCEDURE: Opioid (morphine equivalent mg/kg) and anxiolytic requirements during course 1 (4 days) in patients treated with hu14.18K322A and ch14.18 were reviewed. Correlations between antibody dose and pain scores, opioid requirements, and complement levels were examined for patients receiving hu14.18K322A. RESULTS: Patients treated with hu14.18K322A (n = 19) had lower opioid requirements than those who received ch14.18 (n = 9). The differences in median opioid requirements (mg/kg) were statistically significant for the overall course (1.57 vs. 2.41, P = 0.019) as well as for Days 3 (0.34 vs. 0.65, P = 0.005), and 4 (0.32 vs. 0.64, P = 0.010). No difference in anxiolytic use was observed between the two groups. In the group treated with hu14.18K322A, we found a positive correlation between antibody dose administered and pain scores, but no correlation between antibody dose and opioid requirements or changes in complement levels. CONCLUSIONS: In this retrospective analysis, hu14.18K322A induced less pain than ch14.18 based on opioid requirements. Pediatr Blood Cancer 2015;62:224-228. © 2014 Wiley Periodicals, Inc.

Foundations of the Diagnosis and Management of Idiopathic Intracranial Hypertension and Pulsatile Tinnitus.

Venous sinus stenosis has garnered increasing academic attention as a potential etiology of idiopathic intracranial hypertension (IIH) and pulsatile tinnitus (PT). The complex anatomy of the cerebral venous sinuses and veins plays a crucial role in the pathophysiology of these conditions. Venous sinus stenosis, often found in the superior sagittal or transverse sinus, can lead to elevated intracranial pressure (ICP) and characteristic IIH symptoms. Stenosis, variations in dural venous anatomy, and flow dominance patterns contribute to aberrant flow and subsequent PT. Accurate imaging plays a vital role in diagnosis, and magnetic resonance (MR) venography is particularly useful for detecting stenosis. Management strategies for IIH and PT focus on treating the underlying disease, weight management, medical interventions, and, in severe cases, surgical or endovascular procedures. Recently, venous sinus stenting has gained interest as a minimally invasive treatment option for IIH and PT. Stenting addresses venous sinus stenosis, breaking the feedback loop between elevated ICP and stenosis, thus reducing ICP and promoting cerebrospinal fluid outflow. The correction and resolution of flow aberrances can also mitigate or resolve PT symptoms. While venous sinus stenting remains an emerging field, initial results are promising. Further research is needed to refine patient selection criteria and evaluate the long-term efficacy of stenting as compared to traditional treatments.

Challenges in the use of Venous Sinus Stenting in the Treatment of Idiopathic Intracranial Hypertension and Pulsatile Tinnitus.

Although numerous case series and meta-analyses have shown the efficacy of venous sinus stenting (VSS) in the treatment of idiopathic intracranial hypertension and idiopathic intracranial hypertension-associated pulsatile tinnitus, there remain numerous challenges to be resolved. There is no widespread agreement on candidacy; pressure gradient and failed medical treatment are common indications, but not all clinicians require medical refractoriness as a criterion. Venous manometry, venography, and cerebral angiography are essential tools for patient assessment, but again disagreements exist regarding the best, or most appropriate, diagnostic imaging choice. Challenges with the VSS technique also exist, such as stent choice and deployment. There are considerations regarding postprocedural balloon angioplasty and pharmacologic treatment, but there is insufficient evidence to formalize postoperative decision making. Although complications of VSS are relatively rare, they include in-stent stenosis, hemorrhage, and subdural hematoma, and the learning curve for VSS presents specific challenges in navigating venous anatomy, emphasizing the need for wider availability of high-quality training. Recurrence of symptoms, particularly stent-adjacent stenosis, poses challenges, and although restenting and cerebrospinal fluid-diverting procedures are options, there is a need for clearer criteria for retreatment strategies. Despite these challenges, when comparing VSS with traditional cerebrospinal fluid-diverting procedures, VSS emerges as a favorable option, with strong clinical outcomes, lower complication rates, and cost-effectiveness. Further research is necessary to refine techniques and indications and address specific aspects of VSS to overcome these challenges.

Future Directions and Innovations in Venous Sinus Stenting.

This review explores the future role of venous sinus stenting (VSS) in the management of idiopathic intracranial hypertension and pulsatile tinnitus. Despite its favorable safety profile and clinical outcomes compared with traditional treatments, VSS is not yet the standard of care for these conditions, lacking high-level evidence data and guidelines for patient selection and indications. Current and recently completed clinical trials are expected to provide data to support the adoption of VSS as a primary treatment option. Additionally, VSS shows potential in treating other conditions, such as dural arteriovenous fistula and cerebral venous sinus thrombosis, and it is likely that the procedure will continue to see an expansion of its approved indications. The current lack of dedicated venous stenting technology is being addressed with promising advancements, which may improve procedural ease and patient outcomes. VSS also offers potential for expansion into modulation of brain electrophysiology via endovascular routes, offering exciting possibilities for neurodiagnostics and treatment of neurodegenerative disorders.

Endonasal, supraorbital, and transorbital approaches: minimal access endoscope-assisted surgical approaches for meningiomas in the anterior and middle cranial fossae.

OBJECTIVE: Minimally invasive endoscope-assisted approaches to the anterior skull base offer an alternative to traditional open craniotomies. Given the restrictive operative corridor, appropriate case selection is critical for success. In this paper, the authors present the results of three different minimal access approaches to meningiomas of the anterior and middle fossae and examine the differences in the target areas considered appropriate for each approach, as well as the outcomes, to determine whether the surgical goals were achieved. METHODS: A consecutive series of the endoscopic endonasal approach (EEA), supraorbital approach (SOA), or transorbital approach (TOA) for newly diagnosed meningiomas of the anterior and middle fossa skull base between 2007 and 2022 were examined. Probabilistic heat maps were created to display the distribution of tumor volumes for each approach. Gross-total resection (GTR), extent of resection, visual and olfactory outcomes, and postoperative complications were assessed. RESULTS: Of 525 patients who had meningioma resection, 88 (16.7%) were included in this study. EEA was performed for planum sphenoidale and tuberculum sellae meningiomas (n = 44), SOA for olfactory groove and anterior clinoid meningiomas (n = 36), and TOA for spheno-orbital and middle fossa meningiomas (n = 8). The largest tumors were treated using SOA (mean volume 28 ± 29 cm3), followed by TOA (mean volume 10 ± 10 cm3) and EEA (mean volume 9 ± 8 cm3) (p = 0.024). Most cases (91%) were WHO grade I. GTR was achieved in 84% of patients (n = 74), which was similar to the rates for EEA (84%) and SOA (92%), but lower than that for TOA (50%) (p = 0.002), the latter attributable to spheno-orbital (GTR: 33%) not middle fossa (GTR: 100%) tumors. There were 7 (8%) CSF leaks: 5 (11%) from EEA, 1 (3%) from SOA, and 1 (13%) from TOA (p = 0.326). All resolved with lumbar drainage except for 1 EEA leak that required a reoperation. CONCLUSIONS: Minimally invasive approaches for anterior and middle fossa skull base meningiomas require careful case selection. GTR rates are equally high for all approaches except for spheno-orbital meningiomas, where alleviation of proptosis and not GTR is the primary goal of surgery. New anosmia was most common after EEA.

Does diabetes affect outcome or reoperation rate after lumbar decompression or arthrodesis? A matched analysis of the Quality Outcomes Database data set.

OBJECTIVE: Diabetes mellitus (DM) is a known risk factor for postsurgical and systemic complications after lumbar spinal surgery. Smaller studies have also demonstrated diminished improvements in patient-reported outcomes (PROs), with increased reoperation and readmission rates after lumbar surgery in patients with DM. The authors aimed to examine longer-term PROs in patients with DM undergoing lumbar decompression and/or arthrodesis for degenerative pathology. METHODS: The Quality Outcomes Database was queried for patients undergoing elective lumbar decompression and/or arthrodesis for degenerative pathology. Patients were grouped into DM and non-DM groups and optimally matched in a 1:1 ratio on 31 baseline variables, including the number of operated levels. Outcomes of interest were readmissions and reoperations at 30 and 90 days after surgery in addition to improvements in Oswestry Disability Index, back pain, and leg pain scores and quality-adjusted life-years at 90 days after surgery. RESULTS: The matched decompression cohort comprised 7836 patients (3236 [41.3] females) with a mean age of 63.5 ± 12.6 years, and the matched arthrodesis cohort comprised 7336 patients (3907 [53.3%] females) with a mean age of 64.8 ± 10.3 years. In patients undergoing lumbar decompression, no significant differences in nonroutine discharge, length of stay (LOS), readmissions, reoperations, and PROs were observed. In patients undergoing lumbar arthrodesis, nonroutine discharge (15.7% vs 13.4%, p < 0.01), LOS (3.2 ± 2.0 vs 3.0 ± 3.5 days, p < 0.01), 30-day (6.5% vs 4.4%, p < 0.01) and 90-day (9.1% vs 7.0%, p < 0.01) readmission rates, and the 90-day reoperation rate (4.3% vs 3.2%, p = 0.01) were all significantly higher in the DM group. For DM patients undergoing lumbar arthrodesis, subgroup analyses demonstrated a significantly higher risk of poor surgical outcomes with the open approach. CONCLUSIONS: Patients with and without DM undergoing lumbar spinal decompression alone have comparable readmission and reoperation rates, while those undergoing arthrodesis procedures have a higher risk of poor surgical outcomes up to 90 days after surgery. Surgeons should target optimal DM control preoperatively, particularly for patients undergoing elective lumbar arthrodesis.

Impact of Educational Background on Preoperative Disease Severity and Postoperative Outcomes Among Patients With Cervical Spondylotic Myelopathy.

STUDY DESIGN: Retrospective review of a prospectively maintained database. OBJECTIVE: Assess differences in preoperative status and postoperative outcomes among patients of different educational backgrounds undergoing surgical management of cervical spondylotic myelopathy (CSM). SUMMARY OF BACKGROUND DATA: Patient education level (EL) has been suggested to correlate with health literacy, disease perception, socioeconomic status (SES), and access to health care. METHODS: The CSM data set of the Quality Outcomes Database (QOD) was queried for patients undergoing surgical management of CSM. EL was grouped as high school or below, graduate-level, and postgraduate level. The association of EL with baseline disease severity (per patient-reported outcome measures), symptoms >3 or ≤3 months, and 24-month patient-reported outcome measures were evaluated. RESULTS: Among 1141 patients with CSM, 509 (44.6%) had an EL of high school or below, 471 (41.3%) had a graduate degree, and 161 (14.1%) had obtained postgraduate education. Lower EL was statistically significantly associated with symptom duration of >3 months (odds ratio=1.68), higher arm pain numeric rating scale (NRS) (coefficient=0.5), and higher neck pain NRS (coefficient=0.79). Patients with postgraduate education had statistically significantly lower Neck Disability Index (NDI) scores (coefficient=-7.17), lower arm pain scores (coefficient=-1), and higher quality-adjusted life-years (QALY) scores (coefficient=0.06). Twenty-four months after surgery, patients of lower EL had higher NDI scores, higher pain NRS scores, and lower QALY scores ( P <0.05 in all analyses). CONCLUSIONS: Among patients undergoing surgical management for CSM, those reporting a lower educational level tended to present with longer symptom duration, more disease-inflicted disability and pain, and lower QALY scores. As such, patients of a lower EL are a potentially vulnerable subpopulation, and their health literacy and access to care should be prioritized.

Cervical spondylotic myelopathy and driving abilities: defining the prevalence and long-term postoperative outcomes using the Quality Outcomes Database.

OBJECTIVE: Cervical spondylotic myelopathy (CSM) can cause significant difficulty with driving and a subsequent reduction in an individual's quality of life due to neurological deterioration. The positive impact of surgery on postoperative patient-reported driving capabilities has been seldom explored. METHODS: The CSM module of the Quality Outcomes Database was utilized. Patient-reported driving ability was assessed via the driving section of the Neck Disability Index (NDI) questionnaire. This is an ordinal scale in which 0 represents the absence of symptoms while driving and 5 represents a complete inability to drive due to symptoms. Patients were considered to have an impairment in their driving ability if they reported an NDI driving score of 3 or higher (signifying impairment in driving duration due to symptoms). Multivariable logistic regression models were fitted to evaluate mediators of baseline impairment and improvement at 24 months after surgery, which was defined as an NDI driving score < 3. RESULTS: A total of 1128 patients who underwent surgical intervention for CSM were included, of whom 354 (31.4%) had baseline driving impairment due to CSM. Moderate (OR 2.3) and severe (OR 6.3) neck pain, severe arm pain (OR 1.6), mild-moderate (OR 2.1) and severe (OR 2.5) impairment in hand/arm dexterity, severe impairment in leg use/walking (OR 1.9), and severe impairment of urinary function (OR 1.8) were associated with impaired driving ability at baseline. Of the 291 patients with baseline impairment and available 24-month follow-up data, 209 (71.8%) reported postoperative improvement in their driving ability. This improvement seemed to be mediated particularly through the achievement of the minimal clinically important difference (MCID) in neck pain and improvement in leg function/walking. Patients with improved driving at 24 months noted higher postoperative satisfaction (88.5% vs 62.2%, p < 0.01) and were more likely to achieve a clinically significant improvement in their quality of life (50.7% vs 37.8%, p < 0.01). CONCLUSIONS: Nearly one-third of patients with CSM report impaired driving ability at presentation. Seventy-two percent of these patients reported improvements in their driving ability within 24 months of surgery. Surgical management of CSM can significantly improve patients' driving abilities at 24 months and hence patients' quality of life.

Comparing posterior cervical foraminotomy with anterior cervical discectomy and fusion in radiculopathic patients: an analysis from the Quality Outcomes Database.

OBJECTIVE: The objective of this study was to compare clinical and patient-reported outcomes (PROs) between posterior foraminotomy and anterior cervical discectomy and fusion (ACDF) in patients presenting with cervical radiculopathy. METHODS: The Quality Outcomes Database was queried for patients who had undergone ACDF or posterior foraminotomy for radiculopathy. To create two highly homogeneous groups, optimal individual matching was performed at a 5:1 ratio between the two groups on 29 baseline variables (including demographic characteristics, comorbidities, symptoms, patient-reported scores, underlying pathologies, and levels treated). Outcomes of interest were length of stay, reoperations, patient-reported satisfaction, increase in EQ-5D score, and decrease in Neck Disability Index (NDI) scores for arm and neck pain as long as 1 year after surgery. Noninferiority analysis of achieving patient satisfaction and minimal clinically important difference (MCID) in PROs was performed with an accepted risk difference of 5%. RESULTS: A total of 7805 eligible patients were identified: 216 of these underwent posterior foraminotomy and were matched to 1080 patients who underwent ACDF. The patients who underwent ACDF had more underlying pathologies, lower EQ-5D scores, and higher NDI and neck pain scores at baseline. Posterior foraminotomy was associated with shorter hospitalization (0.5 vs 0.9 days, p < 0.001). Reoperations within 12 months were significantly more common among the posterior foraminotomy group (4.2% vs 1.9%, p = 0.04). The two groups performed similarly in PROs, with posterior foraminotomy being noninferior to ACDF in achieving MCID in EQ-5D and neck pain scores but also having lower rates of maximal satisfaction at 12 months (North American Spine Society score of 1 achieved by 65.2% posterior foraminotomy patients vs 74.6% of ACDF patients, p = 0.02). CONCLUSIONS: The two procedures were found to be offered to different populations, with ACDF being selected for patients with more complicated pathologies and symptoms. After individual matching, posterior foraminotomy was associated with a higher reoperation risk within 1 year after surgery compared to ACDF (4.2% vs 1.9%). In terms of 12-month PROs, posterior foraminotomy was noninferior to ACDF in improving quality of life and neck pain. The two procedures also performed similarly in improving NDI scores and arm pain, but ACDF patients had higher maximal satisfaction rates.

Algorithmic Patient Selection for Minimally Invasive Versus Open Lumbar Interbody Fusion Surgery.

Evidenced-based data-driven decision-making algorithms guide patient and approach selection for adult spinal deformity surgery. Algorithms are continually refined as surgical goals and intraoperative technology evolve.

Use of a High-Fidelity Training Simulator for Minimally Invasive Lumbar Decompression Increases Working Knowledge and Technical Skills Among Orthopedic and Neurosurgical Trainees.

STUDY DESIGN: Prospective comparative study. OBJECTIVE: To quantify the educational benefit to surgical trainees of using a high-fidelity simulator to perform minimally invasive (MIS) unilateral laminotomy for bilateral decompression (ULBD) for lumbar stenosis. METHODS: Twelve orthopedic and neurologic surgery residents performed three MIS ULBD procedures over 2 weeks on a simulator guided by established AO Spine metrics. Video recording of each surgery was rated by three blinded, independent experts using a global rating scale. The learning curve was evaluated with attention to technical skills, skipped steps, occurrence of errors, and timing. A knowledge gap analysis evaluating participants' current vs desired ability was performed after each trial. RESULTS: From trial 1 to 3, there was a decrease in average procedural time by 31.7 minutes. The cumulative number of skipped steps and surgical errors decreased from 25 to 6 and 24 to 6, respectively. Overall surgical proficiency improved as indicated by video rating of efficiency and smoothness of surgical maneuvers, most notably with knowledge and handling of instruments. The greatest changes were noted in junior rather than senior residents. Average knowledge gap analysis significantly decreased by 30% from the first to last trial (P = .001), signifying trainees performed closer to their desired technical goal. CONCLUSION: Procedural metrics for minimally invasive ULBD in combination with a realistic surgical simulator can be used to improve the skills and confidence of trainees. Surgical simulation may offer an important educational complement to traditional methods of skill acquisition and should be explored further with other MIS techniques.

Multidisciplinary management of carotid body tumors: a single-institution case series of 22 patients.

OBJECTIVE: Carotid body tumors (CBTs) are rare, slow-growing neoplasms derived from the parasympathetic paraganglia of the carotid bodies. Although inherently vascular lesions, the role of preoperative embolization prior to resection remains controversial. In this report, the authors describe an institutional series of patients with CBT successfully treated via resection following preoperative embolization and compare the results in this series to previously reported outcomes in the treatment of CBT. METHODS: All CBTs resected between 2013 and 2019 at a single institution were retrospectively identified. All patients had undergone preoperative embolization performed by interventional neuroradiologists, and all had been operated on by a combined team of cerebrovascular neurosurgeons and otolaryngology-head and neck surgeons. The clinical, radiographic, endovascular, and perioperative data were collected. All procedural complications were recorded. RESULTS: Among 22 patients with CBT, 63.6% were female and the median age was 55.5 years at the time of surgery. The most common presenting symptoms included a palpable neck mass (59.1%) and voice changes (22.7%). The average tumor volume was 15.01 ± 14.41 cm3. Most of the CBTs were Shamblin group 2 (95.5%). Blood was predominantly supplied from branches of the ascending pharyngeal artery, with an average of 2 vascular pedicles (range 1-4). Fifty percent of the tumors were embolized with more than one material: polyvinyl alcohol, 95.5%; Onyx, 50.0%; and N-butyl cyanoacrylate glue, 9.1%. The average reduction in tumor blush following embolization was 83% (range 40%-95%). No embolization procedural complications occurred. All resections were performed within 30 hours of embolization. The average operative time was 173.9 minutes, average estimated blood loss was 151.8 ml, and median length of hospital stay was 4 days. The rate of permanent postoperative complications was 0%; 2 patients experienced transient hoarseness, and 1 patient had medical complications related to alcohol withdrawal. CONCLUSIONS: This series reveals that endovascular embolization of CBT is a safe and effective technique for tumor devascularization, making preoperative angiography and embolization an important consideration in the management of CBT. Moreover, the successful management of CBT at the authors' institution rests on a multidisciplinary approach whereby endovascular surgeons, neurosurgeons, and ear, nose, and throat-head and neck surgeons work together to optimally manage each patient with CBT.

Postradiosurgery cystic degeneration in brain metastases causing delayed and potentially severe sequelae: systematic review and illustrative cases.

BACKGROUND: Cystic postradiation degeneration has previously been described in the literature as a rare but potentially severe complication after central nervous system (CNS) irradiation for vascular malformations. Limited cases have been reported in the setting of brain metastases. OBSERVATIONS: Thirty-six total cases, including three reported here, of cystic postradiation degeneration are identified. Of 35 cases with complete clinical information, 34 (97.25%) of 35 were symptomatic from cystic changes at diagnosis. The average time between initial radiation dose and cyst development was 7.61 years (range 2-31 years). Although most patients were initially treated conservatively with medication, including steroids, 32 (88.9%) of 36 ultimately required surgical intervention. The most common interventions were craniotomy for cyst fenestration or resection (25 of 36; 69.4%) and Ommaya placement (8 of 36). After intervention, clinical improvement was seen in 10 (67%) of 15 cases, with persistent or worsening deficit or death seen in 5 (33%) of 15. Cysts were decompressed or obliterated on postoperative imaging in 20 (83.3%) of 24 cases, and recurrence was seen in 4 (16.7%) of 24. LESSONS: Cystic degeneration is a rare and delayed sequela after radiation for brain metastases. This entity has the potential to cause significant and permanent neurological deficit if not properly recognized and addressed. Durable control can be achieved with a variety of surgical treatments, including cyst fenestration and Ommaya placement.

Cervicothoracic junction instrumentation strategies following separation surgery for spinal metastases.

OBJECTIVE: The cervicothoracic junction (CTJ) is a challenging region to stabilize after tumor resection for metastatic spine disease. The objective of this study was to describe the outcomes of patients who underwent posterolateral decompression and instrumented fusion (i.e., separation surgery across the CTJ for instability due to metastatic disease). METHODS: The authors performed a single-institution retrospective study of a prospectively collected cohort of patients who underwent single-approach posterior decompression and instrumented fusion across the CTJ for metastatic spine disease between 2011 and 2018. Adult patients (≥ 18 years old) who presented with mechanical instability, myelopathy, and radiculopathy secondary to metastatic epidural spinal cord compression (MESCC) of the CTJ (C7-T1) from 2011 to 2018 were included. RESULTS: Seventy-nine patients were included, with a mean age of 62.1 years. The most common primary malignancies were non-small cell lung (n = 17), renal cell (11), and prostate (8) carcinoma. The median number of levels decompressed and construct length were 3 and 7, respectively. The average operative time, blood loss, and length of stay were 179.2 minutes, 600.5 ml, and 7.7 days, respectively. Overall, 58 patients received adjuvant radiation, and median dose, fractions, and time from surgery were 27 Gy, 3 fractions, and 20 days, respectively. All patients underwent lateral mass and pedicle screw instrumentation. Forty-nine patients had tapered rods (4.0/5.5 mm or 3.5/5.5 mm), 29 had fixed-diameter rods (3.5 mm or 4.0 mm), and 1 had both. Ten patients required anterior reconstruction with poly-methyl-methacrylate. The overall complication rate was 18.8% (6 patients with wound-related complications, 7 with hardware-related complications, 1 with both, and 1 with other). For the 8 patients (10%) with hardware failure, 7 had tapered rods, all 8 had cervical screw pullout, and 1 patient also experienced rod/screw fracture. The average time to hardware failure was 146.8 days. The 2-year cumulative incidence rate of hardware failure was 11.1% (95% CI 3.7%-18.5%). There were 55 deceased patients, and the median (95% CI) overall survival period was 7.97 (5.79-12.60) months. For survivors, the median (range) follow-up was 12.94 (1.94-71.80) months. CONCLUSIONS: Instrumented fusion across the CTJ demonstrated an 18.8% rate of postoperative complications and an 11% overall 2-year rate of hardware failure in patients who underwent metastatic epidural tumor decompression and stabilization.

Prevalence of Long-Term Low Back Pain After Symptomatic Lumbar Disc Herniation.

OBJECTIVE: Lumbar disc herniation (LDH) is a global issue associated with potentially debilitating long-term consequences, including chronic low back pain (LBP). Short-term outcomes (<2 years) of patients with LDH have been extensively studied and demonstrate improvements in back and leg pain for both operative and conservative management. However, these improvements may not be sustained long-term (>2 years); patients with LDH may develop recurrent disc herniations, progressive degenerative disc disease, and LBP regardless of management strategy. Therefore, our objective is to determine the prevalence of chronic LBP after LDH, understand the relationship between LDH and chronic LBP, and investigate the relationship between radiological findings and postoperative pain outcomes. METHODS: We performed a literature review on the PubMed database via a combination medical subject heading and keyword-based approach for long-term LBP outcomes in patients with LDH. RESULTS: Fifteen studies (2019 patients) evaluated surgical and/or nonoperative outcomes of patients with LDH . Regardless of surgical or nonoperative management, 46.2% of patients with LDH experienced some degree of LBP long-term (range 2-27 years) as compared to a point prevalence of LBP in the general population of only 11.9%. CONCLUSIONS: Patients with LDH are more likely to experience long-term LBP compared to the general population (46.2% vs. 11.9%). Additionally, understanding the relationship between radiological findings and pain outcomes remains a major challenge as the presence of radiological changes and the degree of LBP do not always correlate. Therefore, higher quality studies are needed to better understand the relationship between radiological findings and pain outcomes.