Factors influencing geographic gender disparity in neurosurgery: a nationwide geospatial clustering analysis.

OBJECTIVE: Women neurosurgeons (WNs) continue to remain a minority in the specialty despite significant initiatives to increase their representation. One domain less explored is the regional distribution of WNs, facilitated by the hiring practices of neurosurgical departments across the US. In this analysis, the authors coupled the stated practice location of WNs with regional geospatial data to identify hot spots and cold spots of prevalence and examined regional predictors of increases and decreases in WNs over time. METHODS: The authors examined the National Provider Identifier (NPI) numbers of all neurosurgeons obtained via the National Plan and Provider Enumeration System (NPPES), identifying the percentage of WNs in each county for which data were appended with data from the US Census Bureau. Change in WN rates was identified by calculating a regression slope for all years included (2015-2022). Hot spots and cold spots of WNs were identified through Moran's clustering analysis. Population and surgeon features were compared for hot spots and cold spots. RESULTS: WNs constituted 10.73% of all currently active neurosurgical NPIs, which has increased from 2015 (8.81%). Three hot spots were found-including the Middle Atlantic and Pacific divisions-that contrasted with scattered cold spots throughout the East Central regions that included Memphis as a major city. Although relatively rapidly growing, hot spots had significant gender inequality, with a median WN percentage of 11.38% and a median of 0.61 WNs added to each respective county per year. CONCLUSIONS: The authors analyzed the prevalence of WNs by using aggregated data from the NPPES and US Census Bureau. The authors also show regional hot spots of WNs and that the establishment of WNs in a region is a predictor of additional WNs entering the region. These data suggest that female neurosurgical mentorship and representation may be a major driver of acceptance and further gender diversity in a given region.

Perioperative prophylaxis for surgical site infections in pediatric spinal surgery: a systematic review and network meta-analysis.

OBJECTIVE: Postoperative infections in pediatric spinal surgery commonly occur and necessitate reoperation(s). However, pediatric-specific infection prophylaxis guidelines are not available. This network meta-analysis compares perioperative prophylaxis methods including Betadine irrigation, saline irrigation, intrawound vancomycin powder, combination therapy (Betadine, vancomycin, gentamicin, and cefuroxime), Betadine irrigation plus vancomycin powder, and no intervention to determine the most efficacious prevention method. METHODS: A systematic review was performed by searching the PubMed, EBSCO, Scopus, and Web of Science databases for peer-reviewed articles published prior to February 2022 comparing two or more infection prophylaxis methods in patients younger than 22 years of age. Data were extracted for treatment modalities, patient demographics, and patient outcomes such as total number of infections, surgical site infections, deep infections, intraoperative blood loss, operative time, follow-up time, and postoperative complications. Quality and risk of bias was assessed using National Institutes of Health tools. A network meta-analysis was performed with reduction of infections as the primary outcome. RESULTS: Overall, 10 studies consisting of 5164 procedures were included. There was no significant difference between prophylactic treatment options in reduction of infection. However, three treatment options showed significant reduction in total infection compared with no prophylactic treatment: Betadine plus vancomycin (OR 0.22, 95% CI 0.09-0.54), vancomycin (OR 3.26, 95% CI 1.96-5.44), and a combination therapy (Betadine, vancomycin, gentamicin, and cefuroxime) (OR 0.24, 95% CI 0.07-0.75). P-Score hierarchical ranking estimated Betadine plus vancomycin to be the superior treatment to prevent total infections, deep infections, and surgical site infections (P-score 0.7876, 0.7175, and 0.7291, respectively). No prophylaxis treatment-related complications were reported. CONCLUSIONS: The results of this network meta-analysis show the strongest support for Betadine plus vancomycin as a method to reduce infections following pediatric spinal surgery. There was heterogeneity among studies and inconsistent outcome reporting; however, three effective treatment options are identified.

Mini-open lateral retropleural thoracic discectomy approach.

The lateral retropleural approach provides an eloquent, mini-open, safe corridor to address various pathologies in the thoracolumbar spine, including herniated thoracic discs. Traditional approaches (e.g., transpedicular, costotransversectomy, or transthoracic) have their own benefits and pitfalls but are generally associated with significant morbidity and often require instrumentation. In this video, the authors highlight the retropleural approach and its nuances, including patient positioning, surgical planning, relevant anatomy, surgical technique, and postoperative care. The video can be found here: https://stream.cadmore.media/r10.3171/2022.3.FOCVID2217.

Safe dissection and complication avoidance for L1-2 interbody placement via a lateral access approach.

The lateral access approach for L1-2 interbody placement or other levels at or near the thoracolumbar junction may be difficult without proper knowledge and visualization of anatomy. Specifically, understanding where the fibers of the diaphragm travel and avoiding injury to the diaphragm are paramount. The video can be found here: https://stream.cadmore.media/r10.3171/2022.3.FOCVID2221.

Subclavian Artery to Internal Carotid Artery Interpositional Bypass for Carotid Artery Occlusion: Technical Case Report.

BACKGROUND AND IMPORTANCE: Conventional microsurgical treatment for symptomatic internal carotid artery (ICA) occlusion is revascularization with superficial temporal artery (STA) to middle cerebral artery bypass. However, in rare cases where the common carotid artery, external carotid artery (ECA), or both are also occluded, other microsurgical treatment options must be considered. CLINICAL PRESENTATION: We present the case of a 52-yr-old woman with common carotid artery occlusion and weak ICA flow from collateral connections between the vertebral artery, occipital artery, and ECA. She had ischemic symptoms and a history of stroke. The patient's STA was unsuitable as a donor vessel due to its small caliber and poor flow, and we instead performed an interpositional bypass from the subclavian artery to the ICA using a radial artery graft. CONCLUSION: This case illustrates the successful use of the subclavian artery to ICA bypass technique with an interpositional radial artery graft. The surgical anatomy of the subclavian arteries is reviewed, and the technical details of subclavian artery to radial artery graft to ICA interpositional bypass are presented.

Reimplantation Bypass Using One Limb of a Double-Origin Posterior Inferior Cerebellar Artery for Treatment of a Ruptured Fusiform Aneurysm: Case Report.

BACKGROUND AND IMPORTANCE: Posterior inferior cerebellar artery (PICA) aneurysms are uncommon, and aneurysms associated with anatomical PICA variants are even rarer. Although often treated endovascularly, aneurysms associated with anatomical PICA variants may not be suitable for endovascular intervention because of the risk of compromise of brainstem perforators and may be more amenable to open techniques. This case report describes the successful treatment of an aneurysm associated with a double-origin PICA (DOPICA) by distally reimplanting one of the PICA limbs. CLINICAL PRESENTATION: A 78-yr-old man with a Hunt-Hess grade III, Fisher grade IV subarachnoid hemorrhage secondary to a ruptured distal right PICA aneurysm associated with a DOPICA was treated with PICA-PICA bypass and trapping of the aneurysm. This is the first reported case in the literature of successful bypass of a DOPICA-associated aneurysm. Radiographically, the bypass remained patent with successful obliteration of the aneurysm, and at discharge from the hospital, the patient had a Glasgow Coma Scale score of 15 and modified Rankin Scale score of 3. CONCLUSION: This case demonstrates a novel reimplantation bypass for a ruptured aneurysm that exploits this rare variant anatomy of a DOPICA.

Cerebrospinal fluid area and syringogenesis in Chiari malformation type I.

OBJECTIVE: Syringogenesis in Chiari malformation type I (CM-I) is thought to occur secondary to impaction of the cerebellar tonsils within the foramen magnum (FM). However, the correlation between the CSF area and syringogenesis has yet to be elucidated. The authors sought to determine whether the diminution in subarachnoid space is associated with syringogenesis. Further, the authors sought to determine if syrinx resolution was associated with the degree of expansion of subarachnoid spaces after surgery. METHODS: The authors performed a retrospective review of all patients undergoing posterior fossa decompression for CM-I from 2004 to 2016 at the University of Virginia Health System. The subarachnoid spaces at the FM and at the level of the most severe stenosis were measured before and after surgery by manual delineation of the canal and neural tissue area on MRI and verified through automated CSF intensity measurements. Imaging and clinical outcomes were then compared. RESULTS: Of 68 patients, 26 had a syrinx at presentation. Syrinx patients had significantly less subarachnoid space at the FM (13% vs 19%, p = 0.0070) compared to those without syrinx. Following matching based on degree of tonsillar herniation and age, the subarachnoid space was significantly smaller in patients with a syrinx (12% vs 19%, p = 0.0015). Syrinx resolution was associated with an increase in patients' subarachnoid space after surgery compared with those patients without resolution (23% vs 10%, p = 0.0323). CONCLUSIONS: Syrinx development in CM-I patients is correlated with the degree to which the subarachnoid CSF spaces are diminished at the cranial outlet. Successful syrinx reduction is associated with the degree to which the subarachnoid spaces are increased following surgery.

Hemorrhage risk of cerebral dural arteriovenous fistulas following Gamma Knife radiosurgery in a multicenter international consortium.

OBJECTIVE: The authors performed a study to evaluate the hemorrhagic rates of cerebral dural arteriovenous fistulas (dAVFs) and the risk factors of hemorrhage following Gamma Knife radiosurgery (GKRS). METHODS: Data from a cohort of patients undergoing GKRS for cerebral dAVFs were compiled from the International Radiosurgery Research Foundation. The annual posttreatment hemorrhage rate was calculated as the number of hemorrhages divided by the patient-years at risk. Risk factors for dAVF hemorrhage prior to GKRS and during the latency period after radiosurgery were evaluated in a multivariate analysis. RESULTS: A total of 147 patients with dAVFs were treated with GKRS. Thirty-six patients (24.5%) presented with hemorrhage. dAVFs that had any cortical venous drainage (CVD) (OR = 3.8, p = 0.003) or convexity or torcula location (OR = 3.3, p = 0.017) were more likely to present with hemorrhage in multivariate analysis. Half of the patients had prior treatment (49.7%). Post-GRKS hemorrhage occurred in 4 patients, with an overall annual risk of 0.84% during the latency period. The annual risks of post-GKRS hemorrhage for Borden type 2-3 dAVFs and Borden type 2-3 hemorrhagic dAVFs were 1.45% and 0.93%, respectively. No hemorrhage occurred after radiological confirmation of obliteration. Independent predictors of hemorrhage following GKRS included nonhemorrhagic neural deficit presentation (HR = 21.6, p = 0.027) and increasing number of past endovascular treatments (HR = 1.81, p = 0.036). CONCLUSIONS: Patients have similar rates of hemorrhage before and after radiosurgery until obliteration is achieved. dAVFs that have any CVD or are located in the convexity or torcula were more likely to present with hemorrhage. Patients presenting with nonhemorrhagic neural deficits and a history of endovascular treatments had higher risks of post-GKRS hemorrhage.

CyberKnife radiosurgery for acoustic neuromas: Tumor control and clinical outcomes.

Fractionated CyberKnife radiosurgery (CKRS) treatment for acoustic neuromas may reduce the risk of long-term radiation toxicity to nearby critical structures compared to that of single-fraction radiosurgery. However, tumor control rates and clinical outcomes after CKRS for acoustic neuromas are not well described. We retrospectively reviewed all acoustic neuroma patients treated with CKRS (2004-2011) in a prospectively maintained clinical and radiographic database. Treatment failure, the need for additional surgical intervention, was evaluated using Kaplan-Meier analysis. For 119 treated patients, median values were 49 months (range, 6-133 months) of follow-up, 1.6 cm3 (range, 0.02-17 cm3) tumor volume, and 18 Gy (range, 13-25 Gy) prescribed dose delivered in 3 fractions (range, 1-5 fractions). Thirty-five of 59 patients (59%) with pre-radiosurgery serviceable hearing (American Academy of Otolaryngology-Head and Neck Surgery class A or B) maintained serviceable hearing at the last audio follow-up (median, 21 months). Two of 111 patients (2%) with facial nerve function House-Brackmann (HB) grade ≤3 progressed to HB grade >3 after radiosurgery. Koos grade IV was predictive of radiographic tumor growth after radiosurgery compared to grades I to III (p = 0.02). Treatment failure occurred in 9 of 119 patients (8%); median time to failure was 29 months (range, 4-70 months). The actuarial rates of tumor control at 1, 3, 5, and 7 years were 96%, 94%, 88%, and 88%, respectively. CKRS affords effective tumor control for acoustic neuromas with an acceptable rate of hearing preservation. Further studies are needed to compare CKRS to single-fraction radiosurgery for acoustic neuromas.

High-Grade Aneurysmal Subarachnoid Hemorrhage: Predictors of Functional Outcome.

BACKGROUND: Because the prognosis of high-grade aneurysmal subarachnoid hemorrhage (aSAH), classified as World Federation of Neurosurgical Societies (WFNS) grade IV-V, is generally poor, the functional outcomes of survivors have not been thoroughly explored. The aim of this retrospective cohort study is to determine predictors of functional independence in patients who survive a high-grade aSAH. METHODS: We retrospectively evaluated consecutive patients with aSAH admitted to a single institution from January 2000 to April 2015. Adult (age ≥18 years) patients with WFNS grade IV-V aSAH were included for analysis. Patients without sufficient baseline data, those who died before discharge, and those without follow-up data were excluded. Univariable and multivariable logistic regression analyses were used to identify factors associated with functional independence, defined as a modified Rankin Scale score of 0-2, at last follow-up. RESULTS: Of the 260 patients with a WFNS grade IV-V aSAH during the study period, 139 met the inclusion criteria. After a mean follow-up of 6.3 months, functional independence was achieved in 73% of high-grade aSAH survivors (101/139 patients) and in 39% of all high-grade aSAH cases (101/260 patients). Only a lack of cerebrospinal fluid shunt placement was found to be an independent predictor of functional independence in the multivariable analysis (odds ratio 0.28 [0.109-0.722]; P = 0.008). CONCLUSIONS: Because functional independence can be achieved in the majority of high-grade aSAH survivors, aggressive initial management of high-grade aSAH is warranted. Strategies that reduce the need for permanent cerebrospinal fluid diversion may improve functional outcomes in survivors of high-grade aSAH.

Evaluation of stereotactic radiosurgery for cerebral dural arteriovenous fistulas in a multicenter international consortium.

OBJECTIVE: In this multicenter study, the authors reviewed the results obtained in patients who underwent Gamma Knife radiosurgery (GKRS) for dural arteriovenous fistulas (dAVFs) and determined predictors of outcome. METHODS: Data from a cohort of 114 patients who underwent GKRS for cerebral dAVFs were compiled from the International Gamma Knife Research Foundation. Favorable outcome was defined as dAVF obliteration and no posttreatment hemorrhage or permanent symptomatic radiation-induced complications. Patient and dAVF characteristics were assessed to determine predictors of outcome in a multivariate logistic regression analysis; dAVF-free obliteration was calculated in a competing-risk survival analysis; and Youden indices were used to determine optimal radiosurgical dose. RESULTS: A mean margin dose of 21.8 Gy was delivered. The mean follow-up duration was 4 years (range 0.5-18 years). The overall obliteration rate was 68.4%. The postradiosurgery actuarial rates of obliteration at 3, 5, 7, and 10 years were 41.3%, 61.1%, 70.1%, and 82.0%, respectively. Post-GRKS hemorrhage occurred in 4 patients (annual risk of 0.9%). Radiation-induced imaging changes occurred in 10.4% of patients; 5.2% were symptomatic, and 3.5% had permanent deficits. Favorable outcome was achieved in 63.2% of patients. Patients with middle fossa and tentorial dAVFs (OR 2.4, p = 0.048) and those receiving a margin dose greater than 23 Gy (OR 2.6, p = 0.030) were less likely to achieve a favorable outcome. Commonly used grading scales (e.g., Borden and Cognard) were not predictive of outcome. Female sex (OR 1.7, p = 0.03), absent venous ectasia (OR 3.4, p < 0.001), and cavernous carotid location (OR 2.1, p = 0.019) were predictors of GKRS-induced dAVF obliteration. CONCLUSIONS: GKRS for cerebral dAVFs achieved obliteration and avoided permanent complications in the majority of patients. Those with cavernous carotid location and no venous ectasia were more likely to have fistula obliteration following radiosurgery. Commonly used grading scales were not reliable predictors of outcome following radiosurgery.

The Barrow Innovation Center Case Series: A Novel 3-Dimensional-Printed Retractor for Use with Electromagnetic Neuronavigation Systems.

OBJECTIVE: The Barrow Innovation Center consists of an educational program that promotes interdisciplinary collaboration among neurosurgery, legal, and engineering professionals to foster the development of new medical devices. This report describes a common issue faced during the placement of ventricular shunts for the treatment of hydrocephalus and the solution to this problem that was developed through the Barrow Innovation Center. METHODS: Neurosurgery residents involved in the Barrow Innovation Center presented the problem of ferromagnetic retractors interfering with pinless image-guidance systems at a monthly meeting. Potential solutions were openly discussed by an interdisciplinary committee of neurosurgeons, patent lawyers, and biomedical engineers. The committee decided to pursue development of a novel self-retaining retractor made of nonferromagnetic material as a solution to the problem. RESULTS: Each retractor design was tested in the cadaver laboratory for size and functionality. A final design was chosen and used in a surgical case requiring ventriculoperitoneal shunt placement. The new retractor successfully retracted the scalp without interfering with the electromagnetic image-guidance system. CONCLUSIONS: Through the interdisciplinary Barrow Innovation Center program, a newly designed, 3-dimensional-printed skin and soft-tissue retractor was created, along with an innovative universal shunt retainer. Through this integrated program dedicated to surgical innovation (i.e., the Barrow Innovation Center), the process of developing and implementing new technology at our institution has been streamlined, creating a culture of innovation within the neurosurgery training program.

Effect of Dual Antiplatelet Therapy on Shunt Outcomes in Patients with Aneurysmal Subarachnoid Hemorrhage: A Matched Cohort Pilot Study.

OBJECTIVE: The aim of this retrospective, matched cohort study is to determine the effect of dual antiplatelet therapy (DAPT) on shunt-related complications and long-term functional outcomes in endovascularly treated aneurysmal subarachnoid hemorrhage (aSAH) patients. MATERIALS AND METHOD: We retrospectively analyzed an institutional database of aSAH patients from 2000-2015. Patients who underwent endovascular treatment with stent-assisted coiling (DAPT cohort) were matched in a 1:4 ratio to those who underwent coiling alone (no-DAPT cohort) based on the presenting patient and aneurysm factors. A favorable outcome was defined as a modified Rankin scale of <2. Statistical analyses were performed to compare the shunt-related and functional outcomes between the DAPT and no-DAPT cohorts. RESULTS: After applying the selection criteria and performing the matching process, the overall study cohort comprised 25 aSAH patients who underwent endovascular treatment, including five in the DAPT and 20 in the no-DAPT cohorts. The mean age, World Federation of Neurological Surgeons grade, aneurysm size, and follow-up duration of the overall study cohort were 52.3 years, 2.9, 7.4 mm, and 32.7 months, respectively. The mean time from aSAH to shunt placement was significantly higher for patients in the DAPT cohort (5.6 vs. 0.7 months; p=0.026). The shunt complication rates (p=0.562) and functional outcomes at last follow-up (p=0.924) were not significantly different between the two cohorts. CONCLUSION: Patients receiving DAPT after the stent-assisted coiling of acutely ruptured aneurysms do not have an increased risk of shunt-related complications or unfavorable long-term functional outcomes compared to endovascularly treated aSAH patients not taking DAPT. These results suggest that further study is warranted.

Closure of a giant anterior sacral meningocele with an omental flap in a patient with Marfan syndrome: case report.

Anterior sacral meningoceles (ASMs) are rare lesions often associated with connective tissue disorders. These lesions are typically treated posteriorly via closure of the dural stalk. However, given their insidious nature, ASMs can be quite large on presentation, and this approach may not provide adequate decompression. In this case report, the authors describe the successful treatment of a large ASM through drainage and watertight closure of the cyst with an omental flap. A 43-year-old woman with a history of Marfan syndrome and a large ASM was referred for neurosurgical intervention. The ASM was filling the pelvic cavity and causing severe compression of the bladder. The patient underwent surgical decompression of the cyst through an anterior transabdominal approach and closure of the fistulous tract with a pedicled omental flap. This is the first reported case of successful closure of an ASM with an omental flap. At the 6-month follow-up, the ASM had not recurred on imaging and the patient's symptoms had resolved. Anterior sacral meningoceles are rare lesions that often require neurosurgical intervention. Although most can be treated posteriorly, large ASMs compressing the abdominal or pelvic organs may require a transabdominal approach. Moreover, ASMs with wide dural stalks may benefit from closure with an omental flap.

Shunt-Dependent Hydrocephalus After Aneurysmal Subarachnoid Hemorrhage: Predictors and Long-Term Functional Outcomes.

BACKGROUND: Although chronic hydrocephalus requiring shunt placement is a known sequela of aneurysmal subarachnoid hemorrhage (aSAH), its effect on long-term functional outcomes is incompletely understood. OBJECTIVE: To identify predictors of shunt-dependent hydrocephalus and shunt complications after aSAH and determine the effect of shunt dependence on functional outcomes in aSAH patients. METHODS: We evaluated a database of patients treated for aSAH at a single center from 2000 to 2015. Favorable and unfavorable outcomes were defined as modified Rankin Scale grades 0 to 2 and 3 to 6, respectively. We performed statistical analyses to identify variables associated with shunt-dependent hydrocephalus, unfavorable outcome, and shunt complication. RESULTS: Of the 888 aSAH patients, 116 had shunt-dependent hydrocephalus (13%). Older age (P = .001), intraventricular hemorrhage (IVH) (P = .004), higher World Federation of Neurological Surgeons (WFNS) grade (P < .001), surgical aneurysm treatment (P = .002), and angiographic vasospasm (P = .005) were independent predictors of shunt-dependent hydrocephalus in multivariable analysis. Functional outcome was evaluable in 527 aSAH patients (mean follow-up 18.6 mo), with an unfavorable outcome rate of 17%. Shunt placement (P < .001), shunt infection (P = .041), older age (P < .001), and higher WFNS grade (P = .043) were independently associated with an unfavorable outcome in multivariable analysis. Of the shunt-dependent patients, 18% had a shunt-related complication. Higher WFNS grade (P = .011), posterior circulation aneurysm (P = .018), and angiographic vasospasm (P = .008) were independent predictors of shunt complications in multivariable analysis. CONCLUSION: aSAH patients with shunt-dependent hydrocephalus have significantly poorer long-term functional outcomes. Patients with risk factors for post-aSAH shunt dependence may benefit from increased surveillance, although the effect of such measures is not defined in this study.

Non-traumatic isolated medial cuneiform fracture: A unique mechanism of a rare injury.

We report a case of a 23-year-old woman who sustained a stress fracture to the medial cuneiform. Isolated medial cuneiform fractures are extremely rare with less than 10 cases reported in the literature. The patient initially presented to an urgent care facility complaining of right midfoot pain that occurred while running. Radiographs obtained at the time showed no acute abnormality and the patient was told to resume normal activities. Several weeks later, she presented to urgent care again after exercising, this time unable to bear weight and with swelling and ecchymoses of the right foot. Plain radiographs were again normal, but a high suspicion for injury remained, so a magnetic resonance imaging of the foot was obtained. The advanced imaging showed an acute, non-displaced fracture of the medial cuneiform. Because the fracture was discovered soon after the injury and was non-displaced, she was treated conservatively and at 6-month follow up had returned to all pre-injury activities with no complaints. These rare fractures are often missed at initial presentation because they are usually not evident on plain radiographs. Unless more advanced imaging is obtained to rule out a fracture, a delay of diagnosis can occur resulting in additional morbidity for the patient. Level of clinical evidence: Level 5.

Stereotactic Radiosurgery for Type 1 versus Type 2 Trigeminal Neuralgias.

INTRODUCTION: It remains unclear whether stereotactic radiosurgery (SRS) offers the same benefit for patients with type 2 trigeminal neuralgia (TN2) as for those with type 1 trigeminal neuralgia (TN1). The objective of this study is to compare the outcomes of patients with TN1 and TN2 after SRS. METHODS: SRS outcomes of patients with trigeminal neuralgia treated at a single center from 1994 to 2016 were analyzed. Patients with TN1 were matched to those with TN2 in a 1:1 ratio based on sex, age, pretreatment Barrow Neurological Institute (BNI) pain score, previous treatment, previous facial numbness, and maximum dose. The primary outcome was defined as a BNI pain score of ≤3. RESULTS: The matched TN1 and TN2 cohorts each comprised 56 patients. There were no differences in BNI pain scores at last follow-up, new/worse facial numbness, or pain recurrence, or time to recurrence. Time to initial pain relief after SRS was longer for patients with TN2 (5.4 vs. 4.4 months; P = 0.0016). Actuarial initial pain relief rates were 75%, 90%, and 90% for TN1 and 47%, 77%, and 87% for TN2 at 5, 10, and 15 months, respectively. Actuarial pain relief maintenance rates were 72%, 67%, and 52% for TN1 and 53%, 32%, and 32% for TN2 at 1, 2, and 3 years, respectively. CONCLUSIONS: SRS offers similar rates of initial pain relief, pain score distribution, pain recurrence, and time to pain recurrence between patients with TN1 and TN2. The time to initial pain relief was longer for patients with TN2.

Lumbosacral Subdural Hematoma After Glioblastoma Multiforme Resection: Possible Radiographic Evidence for the Downward Migration of Intracranial Blood.

BACKGROUND: Spinal subdural hematomas (SSDHs) are rare and usually associated with bleeding diatheses, trauma, iatrogenic injury, spinal vascular malformations, or intraspinal tumors. CASE DESCRIPTION: We report a case of a 75-year-old man who developed a symptomatic lumbosacral SSDH after undergoing resection of a right temporal glioblastoma multiforme. The patient subsequently recovered and was discharged home. Over the next 2 weeks, he developed progressively worsening symptoms of lower back pain, lower extremity weakness, and urinary retention. Although the patient had no known risk factors for developing a SSDH, magnetic resonance imaging on postoperative day 16 revealed an extensive L2-sacrum SSDH. The patient underwent L2-L5 total laminectomies for evacuation of the SSDH. His symptoms resolved after surgery. Literature review produced 26 other cases of SSDHs after intracranial surgery in patients without obvious risk factors. In our case, the lumbosacral SSDH may have originated from downward migration of intracranial blood in a gravity-dependent fashion. Radiographic evidence of blood within the posterior thecal sac of the patient's cervical spine supports this hypothesis. CONCLUSIONS: In most cases, SSDHs after intracranial surgery resolve with conservative treatment; however, as shown in our case, surgery may be required if there is progressive neurologic decline. Neurosurgeons should be aware of this potential complication after intracranial surgery; a magnetic resonance imaging of the spine may be indicated if there is unexplained lower extremity pain or weakness.

Endovascular Mechanical Thrombectomy for Acute Middle Cerebral Artery M2 Segment Occlusion: A Systematic Review.

INTRODUCTION: The benefit of endovascular mechanical thrombectomy (EMT) for acute distal occlusions of the middle cerebral artery M2 segment is incompletely defined. The aim of this systematic review is to analyze the recent literature regarding EMT for acute M2 occlusions. METHODS: We reviewed the literature to identify all studies of patients with acute M2 occlusions who underwent EMT that were published after January 1, 2015. Excellent and good outcomes were defined as modified Rankin Scale score of 0-1 and 0-2, respectively, at 3 months. Successful reperfusion was defined as modified Thrombolysis In Cerebral Infarction (mTICI) score of 2b-3. RESULTS: Eight studies, comprising 630 EMT-treated patients with acute M2 occlusions, were included in the analysis. The median National Institute of Health Stroke Scale score ranged from 10 to 16, and the median Alberta Stroke Program Computed Tomography Score ranged from 9 to 10. Excellent and good outcomes at 3-month follow-up were observed in 40% and 62%, respectively, of patients with acute M2 occlusion who underwent EMT, with a mortality of 11%. Successful reperfusion was achieved in 78% of cases. Postprocedural intracerebral hemorrhage (ICH) occurred in 14% of patients, including a symptomatic ICH rate of 5%. CONCLUSIONS: EMT for acute M2 occlusion affords functional independence to most patients, with a modest rate of symptomatic ICH. However, compared with the natural history of distal MCA occlusions, the benefit of M2 thrombectomy using stent retriever or direct aspiration techniques remains unclear.

Early versus late arteriovenous malformation responders after stereotactic radiosurgery: an international multicenter study.

OBJECTIVE The goal of stereotactic radiosurgery (SRS) for arteriovenous malformation (AVM) is complete nidus obliteration, thereby eliminating the risk of future hemorrhage. This outcome can be observed within the first 18 months, although documentation of AVM obliteration can extend to as much as 5 years after SRS is performed. A shorter time to obliteration may impact the frequency and effect of post-SRS complications and latency hemorrhage. The authors' goal in the present study was to determine predictors of early obliteration (18 months or less) following SRS for cerebral AVM. METHODS Eight centers participating in the International Gamma Knife Research Foundation (IGKRF) obtained institutional review board approval to supply de-identified patient data. From a cohort of 2231 patients, a total of 1398 patients had confirmed AVM obliteration. Patients were sorted into early responders (198 patients), defined as those with confirmed nidus obliteration at or prior to 18 months after SRS, and late responders (1200 patients), defined as those with confirmed nidus obliteration more than 18 months after SRS. The median clinical follow-up time was 63.7 months (range 7-324.7 months). RESULTS Outcome parameters including latency interval hemorrhage, mortality, and favorable outcome were not significantly different between the 2 groups. Radiologically demonstrated radiation-induced changes were noted more often in the late responder group (376 patients [31.3%] vs 39 patients [19.7%] for early responders, p = 0.005). Multivariate independent predictors of early obliteration included a margin dose > 24 Gy (p = 0.031), prior surgery (p = 0.002), no prior radiotherapy (p = 0.025), smaller AVM nidus (p = 0.002), deep venous drainage (p = 0.039), and nidus location (p < 0.0001). Basal ganglia, cerebellum, and frontal lobe nidus locations favored early obliteration (p = 0.009). The Virginia Radiosurgery AVM Scale (VRAS) score was significantly different between the 2 responder groups (p = 0.039). The VRAS score was also shown to be predictive of early obliteration on univariate analysis (p = 0.009). For early obliteration, such prognostic ability was not shown for other SRS- and AVM-related grading systems. CONCLUSIONS Early obliteration (≤ 18 months post-SRS) was more common in patients whose AVMs were smaller, located in the frontal lobe, basal ganglia, or cerebellum, had deep venous drainage, and had received a margin dose > 24 Gy.