neuroGPT-X: toward a clinic-ready large language model.

OBJECTIVE: The objective was to assess the performance of a context-enriched large language model (LLM) compared with international neurosurgical experts on questions related to the management of vestibular schwannoma. Furthermore, another objective was to develop a chat-based platform incorporating in-text citations, references, and memory to enable accurate, relevant, and reliable information in real time. METHODS: The analysis involved 1) creating a data set through web scraping, 2) developing a chat-based platform called neuroGPT-X, 3) enlisting 8 expert neurosurgeons across international centers to independently create questions (n = 1) and to answer (n = 4) and evaluate responses (n = 3) while blinded, and 4) analyzing the evaluation results on the management of vestibular schwannoma. In the blinded phase, all answers were assessed for accuracy, coherence, relevance, thoroughness, speed, and overall rating. All experts were unblinded and provided their thoughts on the utility and limitations of the tool. In the unblinded phase, all neurosurgeons provided answers to a Likert scale survey and long-answer questions regarding the clinical utility, likelihood of use, and limitations of the tool. The tool was then evaluated on the basis of a set of 103 consensus statements on vestibular schwannoma care from the 8th Quadrennial International Conference on Vestibular Schwannoma. RESULTS: Responses from the naive and context-enriched Generative Pretrained Transformer (GPT) models were consistently rated not significantly different in terms of accuracy, coherence, relevance, thoroughness, and overall performance, and they were often rated significantly higher than expert responses. Both the naive and content-enriched GPT models provided faster responses to the standardized question set than expert neurosurgeon respondents (p < 0.01). The context-enriched GPT model agreed with 98 of the 103 (95%) consensus statements. Of interest, all expert surgeons expressed concerns about the reliability of GPT in accurately addressing the nuances and controversies surrounding the management of vestibular schwannoma. Furthermore, the authors developed neuroGPT-X, a chat-based platform designed to provide point-of-care clinical support and mitigate the limitations of human memory. neuroGPT-X incorporates features such as in-text citations and references to enable accurate, relevant, and reliable information in real time. CONCLUSIONS: The present study, with its subspecialist-level performance in generating written responses to complex neurosurgical problems for which evidence-based consensus for management is lacking, suggests that context-enriched LLMs show promise as a point-of-care medical resource. The authors anticipate that this work will be a springboard for expansion into more medical specialties, incorporating evidence-based clinical information and developing expert-level dialogue surrounding LLMs in healthcare.

Documented growth of an intracranial capillary hemangioma: A case report.

Intracranial capillary hemangiomas in adults are rare, and diagnosis can be challenging. Hemangiomas, in general (and particularly in the skin), are more often noted in the pediatric population. Due to the lack of imaging undertaken in the presymptomatic phase, the literature provides few clues on the rate of growth of these unusual tumors. Therefore, we report a case of a 64-year-old man with a medical history of Lyme disease who presented with exhaustion and confusion. Imaging demonstrated an intra-axial lesion with vascularity in the posterior right temporal lobe, raising the possibility of a glioma. Imaging two years prior revealed a very small lesion in the same location. The patient underwent a craniectomy, total resection of the lesion was completed, and his symptoms of confusion resolved. Biopsy revealed a capillary hemangioma composed of small vascular channels lined by endothelial cells and pericytes without smooth muscle. Features of glioma, vascular neoplasms or neuroborreliosis (cerebral Lyme disease) were not identified. Our case documents the growth over two years of a rare intracranial capillary hemangioma in an older adult male.

All that glitters: case presentation and review of radial access complications in neurointervention.

Radial artery access has experienced increasing adoption and rapid expansion of indications for neurointerventional procedures. This access is an attractive neurointervention route to be considered, with many advantages over the traditional femoral access in terms of ease of vasculature navigation and decreased risk of complications such as significant bleeding. Although a promising technique for neurointerventional procedures, there are inherent and unique considerations as well as potential complications involved. The following case report highlights some of these vital concepts associated with radial artery access, including appropriate patient selection as well as assessment of arterial size in the context of neurointerventional techniques. Early identification of complications such as arterial injury and compartment syndrome, with an emphasis on appropriate draping and inter-procedure monitoring, is discussed as well as approaches for subsequent management. Finally, the issue of radiation safety in this emerging technique is considered. These concepts are critical for the successful use and the continued growth of radial artery access for neurointervention procedures.

Gender differences in the surgical management of lumbar degenerative disease: a scoping review.

OBJECTIVE: Despite efforts toward achieving gender equality in clinical trial enrollment, females are often underrepresented, and gender-specific data analysis is often unavailable. Identifying and reducing gender bias in medical decision-making and outcome reporting may facilitate equitable healthcare delivery. Gender disparity in the utilization of surgical therapy has been exemplified in the orthopedic literature through studies of total joint arthroplasty. A paucity of literature is available to guide the management of lumbar degenerative disease, which stratifies on the basis of demographic factors. The objective of this study was to systematically map and synthesize the adult surgical literature regarding gender differences in pre- and postoperative patient-reported clinical assessment scores for patients with lumbar degenerative disease (disc degeneration, disc herniation, spondylolisthesis, and spinal canal stenosis). METHODS: A systematic scoping review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) guidelines. MEDLINE, Embase, and the Cochrane Registry of Controlled Trials were searched from inception to September 2018. Study characteristics including patient demographics, diagnoses, procedures, and pre- and postoperative clinical assessment scores (pain, disability, and health-related quality of life [HRQoL]) were collected. RESULTS: Thirty articles were identified, accounting for 32,951 patients. Six studies accounted for 84% of patients; 5 of the 6 studies were published by European groups. The most common lumbar degenerative conditions were disc herniation (59.0%), disc degeneration (20.3%), and spinal canal stenosis (15.9%). The majority of studies reported worse preoperative pain (93.3%), disability (81.3%), and HRQoL (75%) among females. The remainder reported equivalent preoperative scores between males and females. The majority of studies (63.3%) did not report preoperative duration of symptoms, and this represents a limitation of the data. Eighty percent of studies found that females had worse absolute postoperative scores in at least one outcome category (pain, disability, or HRQoL). The remainder reported equivalent absolute postoperative scores between males and females. Seventy-three percent of studies reported either an equivalent or greater interval change for females. CONCLUSIONS: Female patients undergoing surgery for lumbar degenerative disease (disc degeneration, disc herniation, spondylolisthesis, and spinal canal stenosis) have worse absolute preoperative pain, disability, and HRQoL. Following surgery, females have worse absolute pain, disability, and HRQoL, but demonstrate an equal or greater interval change compared to males. Further studies should examine gender differences in preoperative workup and clinical course.

Percutaneous glycerol rhizotomy for trigeminal neuralgia in patients with multiple sclerosis: a long-term retrospective cohort study.

OBJECTIVE: The prevalence of trigeminal neuralgia (TN) in patients with multiple sclerosis (MS-TN) is higher than in the general population (idiopathic TN [ITN]). Glycerol rhizotomy (GR) is a percutaneous lesioning surgery commonly performed for the treatment of medically refractory TN. While treatment for acute pain relief is excellent, long-term pain relief is poorer. The object of this study was to assess the efficacy of percutaneous retrogasserian GR for the treatment of MS-TN versus ITN. METHODS: A retrospective chart review was performed, identifying 219 patients who had undergone 401 GR procedures from 1983 to 2018 at a single academic institution. All patients were diagnosed with medically refractory MS-TN (182 procedures) or ITN (219 procedures). The primary outcome measures of interest were immediate pain relief and time to pain recurrence following initial and repeat GR procedures. Secondary outcomes included medication usage and presence of periprocedural hypesthesia. RESULTS: The initial pain-free response rate was similar between groups (p = 0.726): MS-TN initial GR 89.6%; MS-TN repeat GR 91.9%; ITN initial GR 89.6%; ITN repeat GR 87.0%. The median time to recurrence after initial GR was similar between MS-TN (2.7 ± 1.3 years) and ITN (2.1 ± 0.6 years) patients (p = 0.87). However, there was a statistically significant difference in the time to recurrence after repeat GR between MS-TN (2.3 ± 0.5 years) and ITN patients (1.2 ± 0.2 years; p < 0.05). The presence of periprocedural hypesthesia was highly predictive of pain-free survival (p < 0.01). CONCLUSIONS: Patients with MS-TN achieve meaningful pain relief following GR, with an efficacy comparable to that following GR in patients with ITN. Initial and subsequent GR procedures are equally efficacious.

Sagittal balance influences range of motion: an in vivo study with the ProDisc-C.

BACKGROUND CONTEXT: Cervical arthroplasty is designed to maintain cervical motion of the functional spinal unit after cervical discectomy. The impact of the ProDisc-C (Synthes Spine, Paoli, PA) on in vivo kinematics and sagittal alignment requires further assessment. PURPOSE: The purpose of this study is to test the hypothesis that the ProDisc-C increases range of motion (ROM) in flexion and extension at the surgical level, and assess its impact on cervical alignment. STUDY DESIGN: Clinical study. PATIENT SAMPLE: Fifteen patients with a mean age of 49 years were included in this study. Each patient had a single-level arthroplasty. Patients with multilevel arthroplasty, previous cervical spine surgery, and length of follow-up less than 6 months were excluded from this study. OUTCOME MEASURE: Lateral dynamic radiographs of the cervical spine were analyzed using quantitative measurement analysis (QMA) preoperatively and postoperatively. QMA software was also used to determine the ROM and sagittal translation at the surgical level. METHODS: Flexion/extension lateral radiographs of the cervical spine were prospectively collected and reviewed in 15 patients preoperatively and at early (1-3 months) and late (6-14 months) follow-up after placement of the ProDisc-C. Shell angle (SA) and C2-C7 Cobb angles were measured. Sagittal translation and ROM were calculated at each time point. Preoperative values were compared with early and late follow-up values using paired Student t tests and Pearson's correlation. RESULTS: The C2-C7 Cobb angle did not change significantly after surgery. Segmental ROM increased significantly from neutral to flexion (p=.02) and neutral to extension (p=.002) at late follow-up. SA correlated significantly with ROM from neutral to extension (Pearson's r=-0.55; p=.02) and translation from neutral to extension (Pearson's r=-0.58; p=.02). CONCLUSIONS: The ProDisc-C increased overall segmental ROM. A lordotic SA may be associated with restricted segmental ROM and translation in extension. This study did not detect any change in overall cervical spinal alignment after insertion of the device.

Anterior cervical corpectomy and fusion accelerates degenerative disease at adjacent vertebral segments.

BACKGROUND: Anterior cervical corpectomy provides the most direct and thorough surgical approach for anterior decompression when spinal cord compression is found directly behind the vertebral body. However, anterior cervical fusion has been shown to be associated with the development of new degenerative changes at levels immediately adjacent to the fused segments. Th e incidence of adjacent segment disease (ASD) following anterior cervical corpectomy has not been widely reported. We set out to determine the incidence of clinical ASD following anterior cervical corpectomy. METHODS: We retrospectively reviewed all available medical charts and radiographic studies of all cases of anterior cervical corpectomy performed at the Barrow Neurological Institute over a 4-year period with a minimum 24-month follow-up. Factors assessed included the success of arthrodesis, the presence of degenerative changes on serial follow-up radiographs, and the development of new neurological symptoms. RESULTS: Seventy-six patients met the criteria for inclusion: 54 had undergone a 1-level corpectomy, 18 underwent a 2-level corpectomy, and 4 underwent a 3- or 4-level corpectomy. Arthrodesis was performed with either allograft or autograft and anterior cervical plating. All patients achieved successful fusion. Follow-up was available for a minimum of 2 years in all cases, with a mean length of 3.6 years. Sixteen patients (21%) eventually developed radiological and clinical evidence of degenerative changes at adjacent levels. In 10 of 11 patients who developed clinical symptoms within 2 years, the changes represented progression of pre-existing, asymptomatic degenerative disease. Five patients developed degenerative changes more than 5 years after surgery; these were all associated with an unrelated new insult to the cervical spine such as trauma. CONCLUSIONS: Anterior cervical corpectomy with fixation can accelerate degenerative changes identified preoperatively at adjacent, asymptomatic levels of the cervical spine. LEVEL OF EVIDENCE: Retrospective cohort study (level 2b).

Epidemiology of traumatic spinal cord injury in Canada.

STUDY DESIGN: Retrospective review. OBJECTIVE: To describe the incidence, clinical features, and treatment of traumatic spinal cord injury (SCI) treated at a Canadian tertiary care center. SUMMARY OF BACKGROUND DATA: Understanding the current epidemiology of acute traumatic SCI is essential for public resource allocation and primary prevention. Recent reports suggest that the mean age of patients with SCI may be increasing. METHODS: We retrospectively reviewed hospital records on all patients with traumatic SCI between January 1997 and June 2001 (n = 151). Variables assessed included age, gender, length of hospitalization, type and mechanism of injury, associated spinal fractures, neurologic deficit, and treatment. RESULTS: Annual age-adjusted incidence rates were 42.4 per million for adults aged 15-64 years, and 51.4 per million for those 65 years and older. Motor vehicle accidents accounted for 35% of SCI. Falls were responsible for 63% of SCI among patients older than 65 years and for 31% of injuries overall. Cervical SCI was most common, particularly in the elderly, and was associated with fracture in only 56% of cases. Thoracic and lumbar SCI were associated with spinal fractures in 100% and 85% of cases, respectively. In-hospital mortality was 8%. Mortality was significantly higher among the elderly. Treatment of thoracic and lumbar fractures associated with SCI was predominantly surgical, whereas cervical fractures were equally likely to be treated with external immobilization alone or with surgery. CONCLUSION: A large proportion of injuries was seen among older adults, predominantly as a result of falls. Prevention programs should expand their focus to include home safety and avoidance of falls in the elderly.

Kinematic analysis of the cervical spine following implantation of an artificial cervical disc.

STUDY DESIGN: Prospective cohort study. OBJECTIVE: To assess the biomechanical profile of the cervical spine following cervical arthroplasty. SUMMARY OF BACKGROUND DATA: Spinal arthroplasty offers the promise of maintaining functional spinal motion, thereby potentially avoiding adjacent segment disease. Disc replacement may become the next gold standard for the treatment of degenerative cervical spine disease, and must be studied rigorously to ensure in vivo efficacy and safety. METHODS: A total of 20 patients underwent single or 2-level implantation of the Bryan artificial cervical disc (Medtronic Sofamor Danek, Memphis TN) for treatment of cervical degenerative disc disease producing radiculopathy and/or myelopathy. Lateral neutral, flexion, and extension cervical radiographs were obtained before surgery and at intervals up to 24 months after surgery. Kinematic parameters, including sagittal rotation, horizontal translation, change in disc height, and center of rotation (COR), were assessed for each spinal level using quantitative motion analysis software. RESULTS: Motion was preserved in the operated spinal segments (mean range of motion 7.8 degrees) up to 24 months following surgery. The relative contribution of each spinal segment to overall spinal sagittal rotation differed depending on whether the disc was placed at C5-C6 or C6-C7. Overall cervical motion (C2-C7) was moderately but significantly increased during late follow-up. Sagittal rotation, anterior and posterior disc height, translation, and COR coordinates did not change significantly following surgery. The COR was most frequently located posterior and inferior to the center of the disc space. CONCLUSIONS: The Bryan artificial cervical disc provided in vivo functional spinal motion at the operated level, reproducing the preoperative kinematics of the spondylotic disc.

Percutaneous retrogasserian glycerol rhizotomy in the treatment of tic douloureux associated with multiple sclerosis.

OBJECTIVE: Patients with multiple sclerosis (MS) have a relatively high incidence of tic douloureux (TD) and often do not tolerate medical therapy well. The minimally invasive nature of percutaneous retrogasserian glycerol rhizotomy (PRGR) renders it ideal for first-line surgical treatment of TD. We sought to ascertain the benefits of PRGR in patients with MS and to determine whether hypalgesia after PRGR correlates with efficacy. METHODS: We assessed 97 glycerol procedures performed in 53 patients followed prospectively for treatment of TD associated with MS. Factors assessed included degree of pain relief, postoperative hypalgesia, procedural morbidity, medication use, time to pain recurrence, and number and type of subsequent procedures. RESULTS: Complete pain relief was obtained in 78% of patients after the initial glycerol injection, and partial relief was obtained in 13% of patients. Long-term follow-up (mean, 81 mo) demonstrated a recurrence rate of 59%, with a mean time to recurrence of 17 months. Actuarial recurrence rates were 50% at 12 months and 60% at 24 months. Twenty-four patients underwent a second or subsequent PRGR for recurrent pain and achieved similar rates of pain relief and time to recurrence. Facial sensory loss was associated with a higher likelihood of pain relief (P < 0.05), with longer time to pain recurrence (P < 0.05), and with decreased use of medication after surgery (P < 0.01.) CONCLUSION: PRGR is an effective, low-morbidity surgical procedure in the management of TD complicating MS. The presence of facial sensory loss after PRGR is associated with prolonged efficacy.

Controversies in cervical discectomy and fusion: practice patterns among Canadian surgeons.

OBJECTIVE: Optimal fusion technique and peri-operative management of patients undergoing anterior cervical discectomy (ACD) is unclear. We document current practice patterns among Canadian spinal surgeons regarding the surgical management of single level degenerative cervical spondylosis. METHODS: We conducted a web-based survey of neurosurgeons and spinal orthopedic surgeons in Canada. We asked questions pertaining to the management of single level cervical degenerative disc disease causing radiculopathy and/or myelopathy, including frequency of fusion following single-level discectomy, preferred fusion technique, indications and frequency of use of anterior plating, and use of an external cervical orthosis following surgery. Demographic factors assessed included training background, type and length of practice. RESULTS: Sixty respondents indicated that their practice involved at least 5% spine surgery and were included in further analysis. Neurosurgeons comprised 59% of respondents, and orthopedic surgeons 41%. Fusion was employed 93% of the time following ACD; autologous bone was the preferred fusion material, used in 76% of cases. Neurosurgeons employed anterior cervical plates in 42% of anterior cervical discectomy and fusion cases, whereas orthopedic surgeons used them 70% of the time. External cervical orthoses were recommended for 92% of patients without plates and 61% of patients with plates. Surgeons who had been in practice for less than five years were most likely to be performing spinal surgery, using anterior cervical plates, and recommending the postoperative use of cervical orthoses. CONCLUSION: Practice patterns vary among Canadian surgeons, although nearly all employ fusion and many use instrumentation for single-level ACD. Training background, and type and length of practice influence practice habits.

Effects of a cervical disc prosthesis on segmental and cervical spine alignment.

OBJECT: Cervical arthroplasty offers the promise of maintaining motion of the functional spinal unit (FSU) after anterior cervical discectomy. The impact of cervical arthroplasty on sagittal alignment of the FSU needs to be addressed, together with its effect on overall sagittal balance of the cervical spine. METHODS: The authors prospectively reviewed radiographic and clinical outcomes in 14 patients who received the Bryan Cervical Disc prosthesis (Medtronic Sofamor Danek, Memphis, TN), for whom early (< 6 months) and late (6-24 months) follow-up data were available. Static and dynamic radiographs were measured by hand and computer to determine the angles formed by the endplates of the natural disc preoperatively, those formed by the shells of the implanted prosthesis, the angle of the FSU, and the C2-7 Cobb angle. The range of motion (ROM) was also determined radiographically, whereas clinical outcomes were assessed using the Neck Disability Index (NDI), and Short Form-36 (SF-36) questionnaires. The ROM was preserved following surgery, with a mean preoperative sagittal rotation angle of 8.96 degrees , which was not significantly different from the late postoperative value of 8.25 degrees . When compared with the preoperative disc space angle, the shell endplate angle in the neutral position became kyphotic in the early and late postoperative periods (mean change -3.8 degrees in the late follow-up period; p = 0.0035). The FSU angles also became significantly more kyphotic postoperatively, with a mean change of -6 degrees (p = 0.0006). The Cobb angles varied widely preoperatively and did not change significantly after surgery. There was no statistical correlation between the NDI and SF-36 outcomes and cervical kyphosis. CONCLUSIONS: Cervical arthroplasty preserves motion of the FSU. Both the endplate angle of the treated disc space and the angle of the FSU became kyphotic after insertion of the Bryan prosthesis. The overall sagittal balance of the cervical spine, however, was preserved.

Early clinical and biomechanical results following cervical arthroplasty.

OBJECT: Spinal arthroplasty may become the next gold standard for the treatment of degenerative cervical spine disease. This new modality must be studied rigorously to ensure in vivo efficacy and safety. The authors review the preliminary clinical experience and radiographic outcomes following insertion of the Bryan Cervical Disc Prosthesis (Medtronic Sofamor Danek, Memphis, TN). METHODS: This prospective cohort study included 26 patients undergoing single- or two-level implantation of the Bryan artificial cervical disc for treatment of cervical degenerative disc disease resulting in radiculopathy and/or myelopathy. Radiographic and clinical assessments were made preoperatively 1.5, 3 months, and at 6, 12, and up to 24 months postoperatively. The Neck Disability Index (NDI) and Short Form-36 (SF-36) questionnaires were used to assess pain and functional outcomes. Segmental sagittal rotation from C2-3 to C6-7 was measured using quantitative motion analysis software. A total of 30 Bryan discs were placed in 26 patients. A single-level procedure was performed in 22 patients and a two-level procedure in the other four. Follow-up duration ranged from 1.5 to 27 months, with a mean duration of 12.3 months. A statistically significant improvement in the mean NDI scores was seen between pre- and late postoperative follow-up evaluations. A trend toward improvement in the SF-36 physical component was also found. Motion was preserved in the treated spinal segments (mean range of motion 7.8 degrees ) for up to 24 months postsurgery. The relative contribution of each segment to overall spinal sagittal rotation differed depending on whether the disc was placed at C5-6 or C6-7. Overall cervical motion (C2-7) was moderately increased on late follow-up evaluations. CONCLUSIONS: The Bryan artificial cervical disc provided in vivo functional spinal motion at the treated level. Overall cervical spinal motion was not significantly altered. Sagittal rotation did not change significantly at any level after surgery.

Artificial disc insertion following anterior cervical discectomy.

OBJECTIVE AND IMPORTANCE: Fusion following anterior cervical discectomy has been implicated in the acceleration of degenerative changes in the adjacent spinal segments. Discectomy followed by implantation of an artificial cervical disc maintains the functionality of the spinal unit, while still providing excellent symptomatic relief. We describe our preliminary experience with implantation of the Bryan Cervical Disc System in two cases of single-level cervical disc herniation. CLINICAL PRESENTATION: Two male patients presented with a left C6 radiculopathy, without evidence of myelopathy. Magnetic resonance imaging revealed a disc herniation at C5-6 in both cases. Pre-operative flexion and extension radiographs demonstrated preserved motion at the involved levels. INTERVENTION/TECHNIQUE: Following a standard anterior cervical decompression, precision drilling of the vertebral endplates was carried out using a drill attached to a bed-mounted, gravitationally-referenced retraction frame. An artificial cervical disc, composed of a polyurethane nucleus with titanium endplates, was fitted between the contoured endplates without fixation to the vertebral bodies. No complications were experienced during the insertion of the prosthesis, or in the postoperative course. Both patients experienced immediate postoperative resolution of their radicular pain and were discharged from hospital the following day. At nine months following surgery, both patients continue to have complete relief of radicular symptoms. Postoperative radiographs at six months following surgery confirm accurate placement of the prosthesis and preserved mobility of the functional spinal unit. CONCLUSION: Insertion of the Bryan artificial cervical disc prosthesis following anterior cervical discectomy is a relatively straightforward procedure, which appears to be safe and provides good clinical results, without requiring additional surgical time. Long-term follow-up is required to assess its safety, efficacy, and ability to prevent adjacent segment degeneration.