Clinical Characteristics, Outcomes, and Pathology Analysis in Patients With Dorsal Arachnoid Web.

BACKGROUND: Dorsal arachnoid webs (DAWs) are rare pathological abnormalities of the arachnoid layer of the spinal cord that can result in pain and myelopathy. OBJECTIVE: To present clinical, imaging, and pathological characteristics of patients diagnosed with DAW, case illustrations, and a review of the literature. METHODS: Seventeen cases of DAW between 2015 and 2019 at a tertiary medical center were retrospectively identified through a case log search. Patient characteristics, preoperative imaging, operative notes, and pathology reports were collected. Our main outcome assessed was postoperative resolution of symptoms. Odds ratios were used to determine associations between preoperative signs and symptoms with postoperative symptom resolution. RESULTS: The mean age of the cohort was 50.5 years (IQR = 16) and presented primarily with back pain (64.7%). On imaging, all patients were found to have the "scalpel sign," and nearly half had a syrinx present (41.2%). All DAWs were located in the thoracic spine, with the most common location being the midthoracic (70.6%). The mean follow-up length for all patients was 4.3 months. There were no preoperative symptoms significantly associated with postoperative symptom resolution; however, a trend was noted with the presence of a preoperative syrinx. Pathology samples consistently demonstrated fibroconnective or collagenous tissue with no evidence of inflammation or neoplasm. CONCLUSION: DAW is a rare pathology that can result in myelopathy or inappropriate interventions if misdiagnosed. Surgical intervention using laminectomy with intradural exploration should be considered in symptomatic patients with DAW because it is curative with a strong chance of preoperative symptom resolution with relatively low complication rates.

A multicenter analysis of the prognostic value of histone H3 K27M mutation in adult high-grade spinal glioma.

OBJECTIVE: High-grade spinal glioma (HGSG) is a rare but aggressive tumor that occurs in both adults and children. Histone H3 K27M mutation correlates with poor prognosis in children with diffuse midline glioma. However, the role of H3 K27M mutation in the prognosis of adults with HGSG remains unclear owing to the rarity of this mutation, conflicting reports, and the absence of multicenter studies on this topic. METHODS: The authors studied a cohort of 30 adult patients with diffuse HGSG who underwent histological confirmation of diagnosis, surgical intervention, and treatment between January 2000 and July 2020 at six tertiary academic centers. The primary outcome was the effect of H3 K27M mutation status on progression-free survival (PFS) and overall survival (OS). RESULTS: Thirty patients (18 males and 12 females) with a median (range) age of 50.5 (19-76) years were included in the analysis. Eighteen patients had H3 K27M mutation-positive tumors, and 12 had H3 K27M mutation-negative tumors. The median (interquartile range) PFS was 3 (10) months, and the median (interquartile range) OS was 9 (23) months. The factors associated with increased survival were treatment with concurrent chemotherapy/radiation (p = 0.006 for PFS, and p ≤ 0.001 for OS) and American Spinal Injury Association grade C or better at presentation (p = 0.043 for PFS, and p < 0.001 for OS). There were no significant differences in outcomes based on tumor location, extent of resection, sex, or H3 K27M mutation status. Analysis restricted to HGSG containing necrosis and/or microvascular proliferation (WHO grade IV histological features) revealed increased OS for patients with H3 K27M mutation-positive tumors (p = 0.017). CONCLUSIONS: Although H3 K27M mutant-positive HGSG was associated with poor outcomes in adult patients, the outcomes of patients with H3 K27M mutant-positive HGSG were somewhat more favorable compared with those of their H3 K27M mutant-negative HGSG counterparts. Further preclinical animal studies and larger clinical studies are needed to further understand the age-dependent effects of H3 K27M mutation.

Microsurgical Resection of a Lumbar Synovial Cyst: 2-Dimensional Operative Video.

Lumbar spine synovial cysts develop from degenerated zygapophyseal joints. Symptomatic patients present with radicular pain and weakness or neurogenic claudication.1 In the absence of significant concomitant degenerative spondylolisthesis, symptomatic patients can be managed with a laminectomy and microsurgical resection of the cyst, without the need for instrumented fusion.2,3 In this video, we present the microsurgical resection of a left-sided L4-5 synovial cyst in a 68-yr-old man with radicular pain refractory to conservative management. The radiographical features, relevant surgical anatomy, and salient operative steps are reviewed, and strategies for preventing cyst recurrence are emphasized. There were no complications, the postoperative course was unremarkable, and the patient was discharged on postoperative day 1 with significant improvement in his presenting symptoms. No identifying information is present, and patient consent was obtained for the procedure and for publishing the material included in this video.

Microsurgical Resection of an Intramedullary Spinal Cord Hemangioblastoma Through an Anterior Cervical Approach: 2-Dimensional Operative Video.

This video demonstrates the microsurgical removal of an intramedullary spinal cord hemangioblastoma through an anterior cervical approach. While most spinal hemangioblastomas arise from the dorsal or dorsolateral pial surface and can be safely resected through a posterior approach,1,2 ventral tumors can present a significant challenge to safe surgical removal.3-5 This patient presented with a progressively symptomatic ventral pial based hemangioblastoma at the C5-6 level with large polar cysts extending from C3 to T1. The tumor was approached through a standard anterior cervical exposure with a C5 and C6 corpectomy. Following midline durotomy, the tumor was identified and complete microsurgical resection was achieved. The principles and techniques of tumor resection are illustrated and described in the video. Following tumor resection and dural closure, a fibular allograft was inserted into the corpectomy defect and a C4-C7 fixation plate was placed. The patient was maintained in a supine position for 36 h. He was discharged home on postoperative day 3 in a cervical collar. The patient did well with near-complete recovery of neurological function. Postoperative magnetic resonance imaging at 6 wk showed a substantial resolution of the polar cysts and no evidence of residual tumor. The patient featured in this video consented to the procedure.

Scam Susceptibility in a Young, Schizoaffective Patient with Traumatic Brain Injury: A Case Report with a Review of Financial Exploitation Literature and Possible Therapeutic Interventions Gleaned from Traumatic Brain Injury Rehabilitation Research.

We present here the case of a 27-year-old man with schizoaffective disorder for roughly eight years who, seven years prior to presentation at our institution, suffered a severe traumatic brain injury (TBI) in a car accident. His course since that time has been marked by paranoid and guilty delusions, Cotard delusion (CD), which is the belief he is dead or does not exist, and scam susceptibility leading to the loss of nearly $200,000. He was hospitalized at our institution after his uncle called emergency medical services, concerned about the patient's increasing disorganization and worsening delusions in the setting of medication nonadherence. In our inpatient unit, clozapine was titrated to its highest tolerable dose and, while reality testing appeared and his CD resolved, he remained acutely vulnerable to scams even while hospitalized. We review the existing literature on scam vulnerability, which heretofore has focused primarily on the elderly, and also TBI rehabilitation strategies in an attempt to better understand the underpinnings of this patient's scam susceptibility and to construct a multidisciplinary approach to lessening his susceptibility to financial exploitation in the future.

Subependymomas Are Low-Grade Heterogeneous Glial Neoplasms Defined by Subventricular Zone Lineage Markers.

OBJECTIVE: Subependymomas are infrequent, low-grade gliomas associated with the ventricular system and the spinal cord. Little is known about the origin and natural history of these slow-growing lesions. METHODS: We identified all patients with pathologically proven subependymomas presenting to our institution between 1998 and 2016. We retrospectively reviewed clinical, radiographic, histologic, and surgical outcomes data in all patients who underwent surgical resection. Immunohistochemical analyses for cell lineage markers were performed. RESULTS: A total of 31 patients with pathologically proven subependymomas were identified. Of these, 7 asymptomatic lesions were discovered at autopsy and 24 symptomatic cases were treated surgically. There were 15 (48%) lateral ventricle tumors, 11 (35%) fourth ventricular tumors, and 5 (17%) spinal tumors. Symptomatic intracranial lesions most commonly presented with headaches and balance and gait abnormalities. Subependymomas had no distinguishing radiographic features that provided definitive preoperative diagnosis. At last follow-up, no patient treated surgically experienced recurrence. Immunohistochemical analyses demonstrated a diffusely GFAP-positive glial neoplasm with mixed populations of cells that were variably positive for Olig2, NHERF1, Sox2, and CD44. The Ki67 proliferation index was generally low (<1% in many of the tumors). CONCLUSIONS: Subependymomas demonstrate mixed populations of cells expressing glial lineage markers as well as putative stem cell markers, suggesting these tumors may arise from multipotent glial progenitors that reside in the subventricular zone. Definitive diagnosis requires surgical sampling. Although the clinical course of subependymomas appears benign, the inability to radiographically diagnose these lesions, and the possibility of an alternative malignant lesion support a low threshold for early and safe maximal resection.

A comprehensive assessment of the risk of bone morphogenetic protein use in spinal fusion surgery and postoperative cancer diagnosis.

The risk of postoperative cancer following the use of recombinant human bone morphogenetic protein (BMP)-2 in spinal fusion is one potential complication that has received significant interest. Until recently, there has been little clinical evidence to support the assertion of potential cancer induction after BMP use in spinal surgery. This report aims to summarize the findings from clinical data available to date from the Yale University Open Data Access (YODA) project as well as more recently published large database studies regarding the association of BMP use in spinal fusion and the risk of postoperative cancer. A detailed review was based on online databases, primary studies, FDA reports, and bibliographies of key articles for studies that assessed the efficacy and safety of BMP in spinal fusion. In an analysis of the YODA project, one meta-analysis detected a statistically significant increase in cancer occurrence at 24 months but not at 48 months, and the other meta-analysis did not detect a significant increase in postoperative cancer occurrence. Analysis of 3 large health care data sets (Medicare, MarketScan, and PearlDiver) revealed that none were able to detect a significant increase in risk of malignant cancers when BMP was used compared with controls. The potential risk of postoperative cancer formation following the use of BMP in spinal fusion must be interpreted on an individual basis for each patient by the surgeon. There is no conclusive evidence that application of the common formulations of BMP during spinal surgery results in the formation of cancer locally or at a distant site.

Transoccipital endoscopic fenestration of atrial cysts causing ventricular entrapment.

OBJECT Cystic lesions in the atrium (trigone) of the lateral ventricle may become symptomatic due to obstruction of physiological CSF circulation and/or from mass effect on adjacent structures. A minimally invasive approach that not only allows for straightforward access to multiple regions of the atrial cyst wall, but also enables direct inspection of the entire lateral ventricular system, has not been elaborated. In this paper the authors describe their experience with the endoscopic transoccipital horn approach for treating cystic lesions in the atrium of the lateral ventricle. METHODS A retrospective review was performed of all patients who underwent endoscopic surgical treatment for cysts in the atrium of the lateral ventricle between 1999 and 2014. RESULTS The cohort consisted of 13 consecutive patients who presented with symptomatic lateral ventricular entrapment due to the presence of an atrial cyst. There were 9 male and 4 female patients, with a median age of 5 years. Headache was the most common complaint at presentation. The transoccipital horn approach facilitated successful cyst reduction and fenestration in all cases. Temporal and occipital horn entrapment was reversed in all cases, with reestablishment of a physiological CSF flow pattern throughout the ventricles. Hydrocephalus was also reversed in all patients presenting with this neuroimaging finding at presentation. No cyst or ventricular entrapment was noted to recur during a mean follow-up period of 36 months. No patient in the study cohort required repeat surgery or permanent CSF diversion postoperatively. CONCLUSIONS The endoscopic transoccipital horn approach represents a safe and effective treatment strategy for patients with symptomatic atrial cysts of the lateral ventricle. Using this minimally invasive technique, all poles of the lateral ventricular system can be visualized and the unobstructed flow of CSF can be confirmed after cyst resection obviating the need for additional diversion.

Introduction: Intradural Spinal Surgery video supplement.

This Neurosurgical Focus video supplement contains detailed narrated videos of a broad range of intradural pathology such as neoplasms, including intramedullary, extramedullary, and dumbbell tumors, vascular malformations, functional disorders, and rare conditions that are often overlooked or misdiagnosed such as arachnoid cysts, ventral spinal cord herniation, and dorsal arachnoid web. The intent of this supplement is to provide meaningful educational and instructional content at all levels of training and practice. As such, the selected video submissions each provide a comprehensive detailed narrative description and coordinated video that contains the entire spectrum of relevant information including imaging, operative setup and positioning, and exposure, as well as surgical strategies, techniques, and sequencing toward the safe and effective achievement of the operative objective. This level of detail often necessitated a more lengthy video duration than is typically presented in oral presentations or standard video clips from peer reviewed publications. Unfortunately, space limitations precluded the inclusion of several other excellent video submissions in this supplement. While most videos in this supplement reflect standard operative approaches and techniques there are also submissions that describe innovative exposures and techniques that have expanded surgical options such as ventral approaches, stereotactic guidance, and minimally invasive exposures. There is some redundancy in both the topics and techniques both to underscore fundamental surgical principles as well as to provide complementary perspective from different surgeons. It has been my privilege to serve as guest editor for this video supplement and I would like to extend my appreciation to Mark Bilsky, Bill Krauss, and Sander Connolly for reviewing the large number submitted videos. Most of all, I would like to thank the authors for their skill and effort in the preparation of the outstanding videos that constitute this video supplement.

Microsurgical resection of intramedullary spinal cord hemangioblastoma.

Spinal cord hemangioblastomas account for about 10% of spinal cord tumors. They usually arise from the dorsolateral pia mater and are characterized by their significant vascularity. The principles and techniques of safe resection are different than those employed for the more commonly occurring intramedullary glial tumors (e.g. ependymoma, astrocytoma) and consist of circumferential detachment of the tumor margin from the surrounding normal pia. This video demonstrates the microsurgical techniques of resection of a thoracic spinal cord hemangioblastoma. The video can be found here: http://youtu.be/yT5KLi4VyAo.

Resection of a cervical dumbbell schwannoma with stabilization through a single stage extended posterior approach.

Dumbbell tumors of the cervical spine can present considerable management challenges related to adequate exposure of both intraspinal and paraspinal tumor components, potential injury to the vertebral artery, and spinal stability. This video demonstrates the microsurgical removal of a large cervical dumbbell schwannoma with instrumented fusion via a single stage extended posterior approach. The video shows patient positioning, tumor exposure, and the sequence and techniques of tumor resection, vertebral artery identification and protection, and dural repair. The video can be found here: http://youtu.be/3lIVfKEcxss.

Release and repair of a ventral thoracic spinal cord herniation.

Ventral thoracic spinal cord herniation is a rare but increasingly recognized cause of progressive myelopathy. This video demonstrates the imaging characteristics and surgical techniques for release and reduction of the spinal cord herniation as well as primary repair and reinforcement of the ventral dural hernia defect through an extended posterior approach. An instrumented fusion was concomitantly performed. The video can be found here: http://youtu.be/6Pcokep6Tug.

Microsurgical resection of cauda equina schwannoma with nerve root preservation.

The occurrence of motor deficit following resection of an intradural spinal schwannoma is an uncommon but potentially serious complication. This video illustrates the technique of microsurgical resection of an L-4 sensory nerve root schwannoma with preservation of the corresponding functional L-4 motor nerve root. The video can be found here: http://youtu.be/HrZkGj1JKd4.

Microsurgical enbloc resection of myxopapillary cauda equina ependymoma.

Benign myxopapillary filum terminale ependymomas are often poorly encapsulated and in apposition the cerebrospinal fluid (CSF). These characteristics present the potential surgical risk of CSF dissemination or injury to the delicate cauda equina nerve roots. This video details the techniques of en bloc surgical resection of a filum terminale ependymoma. Treatment strategies and techniques are illustrated to reduce the risk of CSF dissemination and cauda equina injury. The video can be found here: http://youtu.be/LK8AYg-5T7o.

Dorsal arachnoid web.

Dorsal thoracic arachnoid web is a rare but often overlooked cause of progressive myelopathy. Syringomyelia, either above or below the compressive arachnoid band, may also be present. Dorsal arachnoid cyst and ventral spinal cord herniation may be mistaken for this condition. This video demonstrates the microsurgical identification and techniques of resection of a dorsal arachnoid band producing a progressive myelopathy in a 63-year-old man. The video can be found here: http://youtu.be/KDNTqiyW6yo.

Microsurgical resection of intramedullary spinal cord ependymoma.

Ependymomas are the most commonly occurring intramedullary spinal cord tumor in adults. With few exceptions these tumors are histologically benign, although they exhibit some biologic variability with respect to growth rate. While unencapsulated, spinal ependymomas are non-infiltrative and present a clear margin of demarcation from the surrounding spinal cord that serves as an effective dissection plane. This video demonstrates the technique of microsurgical resection of an intramedullary ependymoma through a posterior midline myelotomy. The video can be found here: http://youtu.be/lcHhymSvSqU.

Results of the AANS membership survey of adult spinal deformity knowledge: impact of training, practice experience, and assessment of potential areas for improved education: Clinical article.

OBJECT: Adult spinal deformity (ASD) surgery is increasing in the spinal neurosurgeon's practice. METHODS: A survey of neurosurgeon AANS membership assessed the deformity knowledge base and impact of current training, education, and practice experience to identify opportunities for improved education. Eleven questions developed and agreed upon by experienced spinal deformity surgeons tested ASD knowledge and were subgrouped into 5 categories: (1) radiology/spinopelvic alignment, (2) health-related quality of life, (3) surgical indications, (4) operative technique, and (5) clinical evaluation. Chi-square analysis was used to compare differences based on participant demographic characteristics (years of practice, spinal surgery fellowship training, percentage of practice comprising spinal surgery). RESULTS: Responses were received from 1456 neurosurgeons. Of these respondents, 57% had practiced less than 10 years, 20% had completed a spine fellowship, and 32% devoted more than 75% of their practice to spine. The overall correct answer percentage was 42%. Radiology/spinal pelvic alignment questions had the lowest percentage of correct answers (38%), while clinical evaluation and surgical indications questions had the highest percentage (44%). More than 10 years in practice, completion of a spine fellowship, and more than 75% spine practice were associated with greater overall percentage correct (p < 0.001). More than 10 years in practice was significantly associated with increased percentage of correct answers in 4 of 5 categories. Spine fellowship and more than 75% spine practice were significantly associated with increased percentage correct in all categories. Interestingly, the highest error was seen in risk for postoperative coronal imbalance, with a very low rate of correct responses (15%) and not significantly improved with fellowship (18%, p = 0.08). CONCLUSIONS: The results of this survey suggest that ASD knowledge could be improved in neurosurgery. Knowledge may be augmented with neurosurgical experience, spinal surgery fellowships, and spinal specialization. Neurosurgical education should particularly focus on radiology/spinal pelvic alignment, especially pelvic obliquity and coronal imbalance and operative techniques for ASD.

Cervical spondylotic myelopathy surgical trial: randomized, controlled trial design and rationale.

BACKGROUND: Cervical spondylotic myelopathy (CSM) is the most common cause of spinal cord dysfunction in the world. There are significant practice variation and uncertainty as to the optimal surgical approach for treating CSM. OBJECTIVE: To determine whether ventral surgery is associated with superior Short Form-36 Physical Component Summary outcome at the 1-year follow-up compared with dorsal (laminectomy/fusion or laminoplasty) surgery for the treatment of CSM, to investigate whether postoperative sagittal balance is an independent predictor of overall outcome, and to compare health resource use for ventral and dorsal procedures. METHODS: The study is a randomized, controlled trial with a nonrandomized arm for patients who are eligible but decline randomization. Two hundred fifty patients (159 randomized) with CSM from 11 sites will be recruited over 18 months. The primary outcome is the Short Form-36 Physical Component Summary score. Secondary outcomes include disease-specific outcomes, overall health-related quality of life (EuroQOL 5-dimension questionnaire), and health resource use. EXPECTED OUTCOMES: This will be the first randomized, controlled trial to compare directly the health-related quality-of-life outcomes for ventral vs dorsal surgery for treating CSM. DISCUSSION: A National Institutes of Health-funded (1R13AR065834-01) investigator meeting was held before the initiation of the trial to bring multiple stakeholders together to finalize the study protocol. Study investigators, coordinators, and major stakeholders were able to attend and discuss strengths of, limitations of, and concerns about the study. The final protocol was approved for funding by the Patient-Centered Outcomes Research Institute (CE-1304-6173). The trial began enrollment on April 1, 2014.

The National Neurosurgery Quality and Outcomes Database and NeuroPoint Alliance: rationale, development, and implementation.

Patient care data will soon inform all areas of health care decision making and will define clinical performance. Organized neurosurgery believes that prospective, systematic tracking of practice patterns and patient outcomes will allow neurosurgeons to improve the quality and efficiency and, ultimately, the value of care. In support of this mission, the American Association of Neurological Surgeons, in cooperation with a broad coalition of other neurosurgical societies including the Congress of Neurological Surgeons, Society of Neurological Surgeons, and American Board of Neurological Surgery, created the NeuroPoint Alliance (NPA), a not-for-profit corporation, in 2008. The NPA coordinates a variety of national projects involving the acquisition, analysis, and reporting of clinical data from neurosurgical practice using online technologies. It was designed to meet the health care quality and related research needs of individual neurosurgeons and neurosurgical practices, national organizations, health care plans, biomedical industry, and government agencies. To meet the growing need for tools to measure and promote high-quality care, NPA collaborated with several national stakeholders to create an unprecedented program: the National Neurosurgery Quality and Outcomes Database (N(2)QOD). This resource will allow any US neurosurgeon, practice group, or hospital system to contribute to and access aggregate quality and outcomes data through a centralized, nationally coordinated clinical registry. This paper describes the practical and scientific justifications for a national neurosurgical registry; the conceptualization, design, development, and implementation of the N(2)QOD; and the likely role of prospective, cooperative clinical data collection systems in evolving systems of neurosurgical training, continuing education, research, public reporting, and maintenance of certification.