Contrast-Induced Encephalopathy and the Blood-Brain Barrier.

BACKGROUND: Contrast-induced encephalopathy (CIE) is an adverse event associated with diagnostic and therapeutic endovascular procedures. Decades of animal and human research support a mechanistic role for pathological blood-brain barrier dysfunction (BBBd). Here, we describe an institutional case series and review the literature supporting a mechanistic role for BBBd in CIE. METHODS: A literature review was conducted by searching MEDLINE, Web of Science, Embase, CINAHL and Cochrane databases from inception to January 31, 2022. We searched our institutional neurovascular database for cases of CIE following endovascular treatment of cerebrovascular disease during a 6-month period. Informed consent was obtained in all cases. RESULTS: Review of the literature revealed risk factors for BBBd and CIE, including microvascular disease, pathological neuroinflammation, severe procedural hypertension, iodinated contrast load and altered cerebral blood flow dynamics. In our institutional series, 6 of 52 (11.5%) of patients undergoing therapeutic neuroendovascular procedures developed CIE during the study period. Four patients were treated for ischemic stroke and two patients for recurrent cerebral aneurysms. Mechanical stenting or thrombectomy were utilized in all cases. CONCLUSION: In this institutional case series and literature review of animal and human data, we identified numerous shared risk factors for CIE and BBBd, including microvascular disease, increased procedure length, large contrast volumes, severe intraoperative hypertension and use of mechanical devices that may induce iatrogenic endothelial injury.

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.

Management of Ruptured Intracranial Aneurysms in the Post-International Subarachnoid Aneurysm Trial Era: A Single-Centre Prospective Series.

BACKGROUND: Aneurysmal subarachnoid haemorrhage (aSAH) is associated with significant morbidity and mortality. The International Subarachnoid Aneurysm Trial (ISAT) reported reduced morbidity in patients treated with endovascular coiling versus surgical clipping. However, recent studies suggest that there is no significant difference in clinical outcomes. This study examines the outcomes of either technique for treating aSAH during the 15 years post-ISAT at a Canadian quaternary centre. METHODS: We reviewed prospectively collected data of patients admitted with aSAH from January 2002 to December 2017. Glasgow Outcome Scale (GOS) was compared at discharge, 6 months and 12 months' follow-up using univariate and multivariable ordinal logistic regression. Post-operative complications were assessed using binary logistic regression. RESULTS: Two-hundred and eighty-seven patients were treated with coiling and 95 patients with clipping. The mean age of clipped patients was significantly younger, and hypertension was significantly commoner in coiled patients. A greater proportion of coiled aneurysms were located in the posterior circulation. No difference in the odds of having a favourable GOS was seen between patients who were clipped versus coiled at any of follow-up time points on univariate or multivariable analysis. In both treatment groups, patient recovery to independence (GOS 4-5) was seen from discharge to 6 months, but not from 6 to 12 months' follow-up, without difference between clipping and coiling. CONCLUSION: These real-world findings suggest clipping remains an effective and important treatment option for patients with aSAH who do not meet ISAT inclusion criteria. The results can assist in clinical decision-making processes and understanding of the natural recovery progression of aSAH.

Practical uses of the BENCHMARK™ BMX®81 in the road less travelled: Guide catheter comparison for radial access in neurovascular intervention.

BACKGROUND: Radial arterial access has gained interest for neurovascular procedures in recent years. Although there are no randomized control trials for neurointervention procedures using radial access, there is growing literature demonstrating its feasibility and favorable outcomes. Equipment technical improvements, like the recently introduced BENCHMARK™ BMX®81 System, have made radial navigation safer, with improved maneuverability and support for a variety of procedures. We present a multicenter case series highlighting our institutional radial access experience comparing the BMX®81 with alternative catheters. METHODS: Multicenter retrospective cohort study of 80 patients who underwent neurovascular procedures through a radial approach. In half of the cases a BENCHMARK™ BMX®81 System was used. The comparison group consisted of the BENCHMARK™071 and 96, Neuron MAX®088 and BALLAST™ systems. Procedures included endovascular thrombectomy, carotid and brachiocephalic artery stenting, middle meningeal artery embolization, flow diverter stenting, vertebral artery sacrifice, aneurysm coiling, and WEB™ device deployment. RESULTS: In our series, the BMX®81 was successful in the navigation of the anatomy to the target location in 95% of cases. No radial access or BMX®81 related complications were identified. There was no significant difference in fluoroscopy time between the BMX81 and the comparison group. Four patients in the comparison group had catheter-related complications due to vasospasm. Eighty-six percent of BMX®81 cases had satisfactory outcomes and no technical difficulties. The remainder presented technical difficulties, but none of these were considered secondary to the puncture site or support structure. CONCLUSIONS: The BENCHMARK™ BMX®81 System is a recently developed guiding catheter which has design and size features supporting radial access for a variety of neurovascular interventions. Early multicenter experience highlights the ease of use and versatility of this new catheter as an alternative to transfemoral access as well as other catheters used for radial access.

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.

Comparative Efficacy of Flow Diverter Devices in the Treatment of Carotid Sidewall Intracranial Aneurysms: a Retrospective, Multicenter Study.

BACKGROUND: The comparative efficacy and safety of first-generation flow diverters (FDs), Pipeline Embolization Device (PED) (Medtronic, Irvine, California), Silk (Balt Extrusion, Montmorency, France), Flow Re-direction Endoluminal Device (FRED) (Microvention, Tustin, California), and Surpass Streamline (Stryker Neurovascular, Fremont, California), is not directly established and largely inferred. PURPOSE: This study aimed to compare the efficacy of different FDs in treating sidewall ICA intracranial aneurysms. METHODS: We conducted a retrospective review of prospectively maintained databases from eighteen academic institutions from 2009-2016, comprising 444 patients treated with one of four devices for sidewall ICA aneurysms. Data on demographics, aneurysm characteristics, treatment outcomes, and complications were analyzed. Angiographic and clinical outcomes were assessed using various imaging modalities and modified Rankin Scale (mRS). Propensity score weighting was employed to balance confounding variables. The data analysis used Kaplan-Meier curves, logistic regression, and Cox proportional-hazards regression. RESULTS: While there were no significant differences in retreatment rates, functional outcomes (mRS 0-1), and thromboembolic complications between the four devices, the probability of achieving adequate occlusion at the last follow-up was highest in Surpass device (HR: 4.59; CI: 2.75-7.66, p < 0.001), followed by FRED (HR: 2.23; CI: 1.44-3.46, p < 0.001), PED (HR: 1.72; CI: 1.10-2.70, p = 0.018), and Silk (HR: 1.0 ref. standard). The only hemorrhagic complications were with Surpass (1%). CONCLUSION: All the first-generation devices achieved good clinical outcomes and retreatment rates in treating ICA sidewall aneurysms. Prospective studies are needed to explore the nuanced differences between these devices in the long term.

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.

Electrothermal Coil Detachment Failure in Flow Diverter-Assisted Coiling of a Small Blister Aneurysm: Technical Considerations and Possible Solutions.

Flow diversion stenting combined with coiling offers both immediate protection from rebleeding for ruptured aneurysms and long-term stability for wide-necked or blister aneurysms. It is particularly useful for tiny ruptured aneurysms, alleviating the concern that small coils may prolapse between the struts of conventional stents. We employed this technique in a very small, broad-based ruptured aneurysm of the internal carotid, jailing the coiling microcatheter with a Pipeline Embolization Device. However, coil detachment repeatedly failed, until we withdrew the detachment zone into the microcatheter. We suggest that if the tip of the coiling catheter is adjacent to the stent, contact between the junction zone of the coil and the high metal density of the flow diverter may prevent proper electrothermal coil detachment. Detachment can be undertaken successfully within the microcatheter, though care must be taken thereafter to fully push the detached coil tail into the aneurysm.

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.

Complications with cervical arthroplasty.

OBJECT: Spinal arthroplasty is becoming more widely performed in the treatment of degenerative cervical disc disease. Although this new technology may offer benefits over arthrodesis, it also requires that the surgeon acquire new operative techniques, and new potential complications are introduced. To determine the incidence and distribution of perioperative complications, the authors analyzed their early data obtained in a series of patients treated with the Bryan Cervical Disc prosthesis. METHODS: The authors prospectively recorded operative data, complications, and clinical and radiographic outcome data in all patients treated with Bryan prosthesis-based arthroplasty at two tertiary care centers since 2001. Patients underwent standard anterior cervical discectomy followed by one- to three-level arthroplasty. Ninety-six discs were implanted in 74 patients. The perioperative complication rate was 6.2% per treated level. In one patient a retropharyngeal hematoma developed, requiring evacuation. Neurological worsening occurred in three patients. Intraoperative migration of the prosthesis was observed in one two-level case, whereas delayed migration occurred in one patient with postoperative segmental kyphosis. In another patient with severe postoperative segmental kyphosis, revision was required with a customized lordotic prosthesis. Heterotopic ossification and spontaneous fusion occurred in two cases; motion was preserved in the remaining 94 prostheses. Partial dislocation of the prosthesis in extension occurred in one patient with preoperative segmental hypermobility, the first reported failure of a Bryan prosthesis. Twenty-five percent of patients reported neck and shoulder pain during the late follow-up period. There was a trend toward increased kyphosis of the C2-7 curvature postoperatively. CONCLUSIONS: The Bryan prosthesis was effective in maintaining spinal motion. Major perioperative and device-related complications were infrequent.

Cervical total disc replacement, part two: clinical results.

This article focuses on the clinical results of three prostheses (the Bryan Cervical Disc, the Bristol Disc, and the ProDisc-C) for cervical total disc replacement. Background on the development, design, and biomechanical characteristics of each prosthesis is given and surgical indications and clinical results are summarized and analyzed.

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.

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.

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.