Neuro-imaging in intracerebral hemorrhage: updates and knowledge gaps.

Intracerebral hemorrhage (ICH) is characterized by hematoma development within the brain's parenchyma, contributing significantly to the burden of stroke. While non-contrast head computed tomography (CT) remains the gold standard for initial diagnosis, this review underscores the pivotal role of magnetic resonance imaging (MRI) in ICH management. Beyond diagnosis, MRI offers invaluable insights into ICH etiology, prognosis, and treatment. Utilizing echo-planar gradient-echo or susceptibility-weighted sequences, MRI demonstrates exceptional sensitivity and specificity in identifying ICH, aiding in differentiation of primary and secondary causes. Moreover, MRI facilitates assessment of hemorrhage age, recognition of secondary lesions, and evaluation of perihematomal edema progression, thus guiding tailored therapeutic strategies. This comprehensive review discusses the multifaceted utility of MRI in ICH management, highlighting its indispensable role in enhancing diagnostic accuracy as well as aiding in prognostication. As MRI continues to evolve as a cornerstone of ICH assessment, future research should explore its nuanced applications in personalized care paradigms.

Early Experience With Artificial Intelligence Software to Detect Intracranial Occlusive Stroke in Trauma Patients.

Objective Identifying ischemic stroke is a diagnostic challenge in the trauma subpopulation. We describe our early experience with artificial intelligence-assisted image analysis software for automatically identifying acute ischemic stroke in trauma patients.  Methods Patients were retrospectively screened for (i) admission to the trauma service at a level one trauma center between 2020 and 2022, (ii) radiologist-confirmed intracranial occlusion, (iii) occlusion identified on computed tomography angiography performed within 24 hours of admission, (iv) no intracranial hemorrhage, and (v) contemporaneous analysis with the large vessel occlusion (LVO) detection program. Baseline characteristics, stroke detection, response-activation, and outcome data were summarized.  Results Of 9893 trauma patients admitted, 88 (0.89%) patients had a cerebral stroke diagnosis, of which 10 patients (10/88; 11.4%) met inclusion criteria. Most patients were admitted following a fall (8/10; 80%). Six (6/10; 60.0%) patients had LVOs. The program correctly detected 83.3% (5/6) of patients, and these patients were triaged in less than one hour from arrival on average. The program did not falsely identify non-LVOs as LVOs for any patients. Conclusions Identifying adjunct tools to aid timely identification and treatment of ischemic stroke in trauma patients is necessary to increase the chances for meaningful neurological recovery. Our early experience exhibited potential for using automated software to aid occlusion identification and subsequent stroke team mobilization. Future studies in larger cohorts will expand upon these preliminary findings to establish the accuracy and clinical benefit of automated stroke detection tool integration for the trauma population.

The natural history of aneurysms incompletely occluded by placement of a flow diverter: a multiinstitutional study.

OBJECTIVE: Treatment of intracranial aneurysms by flow diversion is safe and effective and is increasingly popular. However, the correct treatment paradigm for aneurysms incompletely treated by initial placement of a flow diverter has not been established, nor have the subsequent natural history and occlusion rates of such aneurysms. The authors sought to outline the natural history of such aneurysms, which to date have been considered partially treated. METHODS: The authors retrospectively reviewed consecutive cases from 6 high-volume neurointerventional services, including all cases in which the first follow-up imaging after placement of a flow diverter showed incomplete occlusion of the aneurysm, and for which subsequent clinical and/or radiological follow-up was available. All included patients were treated with the Pipeline Flex embolization device or the Pipeline Flex embolization device with Shield Technology. Subsequent radiographic and clinical outcome data were collected and analyzed using the Kaplan-Meier survival function. RESULTS: A total of 263 patients with persistently patent aneurysms on first follow-up imaging after flow diversion were identified. Of these, 204 had clinical follow-up and 152 had additional imaging follow-up. Of this final cohort, 148 aneurysms were unruptured, and 4 were ruptured. The average aneurysm size by maximum dimension was 10.8 mm. The average recorded follow-up was 27.8 months in the cohort, with some patients followed for as long as 9 years from treatment. Over the course of 403 person-years of follow-up, no delayed aneurysm ruptures were recorded. Both with and without retreatment, aneurysms showed a trend toward progressive occlusion over time. Complications related to device placement were low. CONCLUSIONS: Aneurysms that have been incompletely treated by flow diversion have a benign natural history with progression toward occlusion over time, with or without retreatment.

The Influence of Coagulopathy on Radiographic and Clinical Outcomes in Patients Undergoing Middle Meningeal Artery Embolization as Standalone Treatment for Non-acute Subdural Hematomas.

Middle meningeal artery embolization (MMAE) is emerging as a safe and effective standalone intervention for non-acute subdural hematomas (NASHs); however, the risk of hematoma recurrence after MMAE in coagulopathic patients is unclear. To characterize the impact of coagulopathy on treatment outcomes, we analyzed a multi-institutional database of patients who underwent standalone MMAE as treatment for NASH. We classified 537 patients who underwent MMAE as a standalone intervention between 2019 and 2023 by coagulopathy status. Coagulopathy was defined as use of anticoagulation/antiplatelet agents or pre-operative thrombocytopenia (platelets <100,000/µL). Demographics, pre-procedural characteristics, in-hospital course, and patient outcomes were collected. Thrombocytopenia, aspirin use, antiplatelet agent use, and anticoagulant use were assessed using univariate and multivariate analyses to identify any characteristics associated with the need for rescue surgical intervention, mortality, adverse events, and modified Rankin Scale score at 90-day follow-up. Propensity score-matched cohorts by coagulopathy status with matching covariates adjusting for risk factors implicated in surgical recurrence were evaluated by univariate and multivariate analyses. Minimal differences in pre-operative characteristics between patients with and those without coagulopathy were observed. On unmatched and matched analyses, patients with coagulopathy had higher rates of requiring subsequent surgery than those without (unmatched: 9.9% vs. 4.3%; matched: 12.6% vs. 4.6%; both p < 0.05). On matched multivariable analysis, patients with coagulopathy had an increased odds ratio (OR) of requiring surgical rescue (OR 3.95; 95% confidence interval [CI] 1.68-9.30; p < 0.01). Antiplatelet agent use (ticagrelor, prasugrel, or clopidogrel) was also predictive of surgical rescue (OR 4.38; 95% CI 1.51-12.72; p = 0.01), and patients with thrombocytopenia had significantly increased odds of in-hospital mortality (OR 5.16; 95% CI 2.38-11.20; p < 0.01). There were no differences in follow-up radiographic and other clinical outcomes in patients with and those without coagulopathy. Patients with coagulopathy undergoing standalone MMAE for treatment of NASH may have greater risk of requiring surgical rescue (particularly in patients using antiplatelet agents), and in-hospital mortality (in thrombocytopenic patients).

Correlating Age and Hematoma Volume with Extent of Midline Shift in Acute Subdural Hematoma Patients: Validation of an Artificial Intelligence Tool for Volumetric Analysis.

OBJECTIVE: Decision for intervention in acute subdural hematoma patients is based on a combination of clinical and radiographic factors. Age has been suggested as a factor to be strongly considered when interpreting midline shift (MLS) and hematoma volume data for assessing critical clinical severity during operative intervention decisions for acute subdural hematoma patients. The objective of this study was to demonstrate the use of an automated volumetric analysis tool to measure hematoma volume and MLS and quantify their relationship with age. METHODS: A total of 1789 acute subdural hematoma patients were analyzed using qER-Quant software (Qure.ai, Mumbai, India) for MLS and hematoma volume measurements. Univariable and multivariable regressions analyzed association between MLS, hematoma volume, age, and MLS:hematoma volume ratio. RESULTS: In comparison to young patients (≤ 70 years), old patients (>70 years) had significantly higher average hematoma volume (old: 62.2 mL vs. young 46.8 mL, P < 0.0001), lower average MLS (old: 6.6 mm vs. young: 7.4 mm, P = 0.025), and lower average MLS:hematoma volume ratio (old: 0.11 mm/mL vs. young 0.15 mm/mL, P < 0.0001). Young patients had an average of 1.5 mm greater MLS for a given hematoma volume in comparison to old patients. With increasing age, the ratio between MLS and hematoma volume significantly decreases (P = 0.0002). CONCLUSIONS: Commercially available, automated, artificial intelligence (AI)-based tools may be used for obtaining quantitative radiographic measurement data in patients with acute subdural hematoma. Our quantitative results are consistent with the qualitative relationship previously established between age, hematoma volume, and MLS, which supports the validity of using AI-based tools for acute subdural hematoma volume estimation.

General Versus Nongeneral Anesthesia for Middle Meningeal Artery Embolization for Chronic Subdural Hematomas: Multicenter Propensity Score Matched Study.

BACKGROUND AND OBJECTIVES: The choice of anesthesia type (general anesthesia [GA] vs nongeneral anesthesia [non-GA]) in middle meningeal artery embolization (MMAE) procedures for chronic subdural hematomas (cSDH) differs between institutions and left to care team discretion given lack of standard guidelines. We compare the outcomes of GA vs non-GA in MMAE. METHODS: Consecutive patients receiving MMAE for cSDH at 14 North American centers (2018-2023) were included. Clinical, cSDH characteristics, and technical/clinical outcomes were compared between the GA/non-GA groups. Using propensity score matching (PSM), patients were matched controlling for age, baseline modified Rankin Scale, concurrent/prior surgery, hematoma thickness/midline shift, and baseline antiplatelet/anticoagulation. The primary end points included surgical rescue and radiographic success rates (≥50% reduction in maximum hematoma thickness with minimum 2 weeks of imaging). Secondary end points included technical feasibility, procedural complications, and functional outcomes. RESULTS: Seven hundred seventy-eight patients (median age 73 years, 73.2% male patients) underwent 956 MMAE procedures, 667 (70.4%) were non-GA and 280 were GA (29.6%). After running 1:3 PSM algorithm, this resulted in 153 and 296 in the GA and non-GA groups, respectively. There were no baseline/procedural differences between the groups except radial access more significantly used in the non-GA group (P = .001). There was no difference between the groups in procedural technical feasibility, complications rate, length of stay, surgical rescue rates, or favorable functional outcome at the last follow-up. Subsequent 1:1 sensitivity PSM retained the same results. Bilateral MMAE procedures were more performed under non-GA group (75.8% vs 67.2%; P = .01); no differences were noted in clinical/radiographic outcomes between bilateral vs unilateral MMAE, except for longer procedure duration in the bilateral group (median 73 minutes [IQR 48.3-100] vs 54 minutes [39-75]; P < .0001). Another PSM analysis comparing GA vs non-GA in patients undergoing stand-alone MMAE retained similar associations. CONCLUSION: We found no significant differences in radiological improvement/clinical outcomes between GA and non-GA for MMAE.

Microsurgical Clipping of Unruptured Anterior Circulation Aneurysms-A Global Multicenter Investigation of Perioperative Outcomes.

BACKGROUND AND OBJECTIVES: Microsurgical aneurysm repair by clipping continues to be highly important despite increasing endovascular treatment options, especially because of inferior occlusion rates. This study aimed to present current global microsurgical treatment practices and to identify risk factors for complications and neurological deterioration after clipping of unruptured anterior circulation aneurysms. METHODS: Fifteen centers from 4 continents participated in this retrospective cohort study. Consecutive patients who underwent elective microsurgical clipping of untreated unruptured intracranial aneurysm between January 2016 and December 2020 were included. Posterior circulation aneurysms were excluded. Outcome parameters were postsurgical complications and neurological deterioration (defined as decline on the modified Rankin Scale) at discharge and during follow-up. Multivariate regression analyses were performed adjusting for all described patient characteristics. RESULTS: Among a total of 2192 patients with anterior circulation aneurysm, complete occlusion of the treated aneurysm was achieved in 2089 (95.3%) patients at discharge. The occlusion rate remained stable (94.7%) during follow-up. Regression analysis identified hypertension (P < .02), aneurysm diameter (P < .001), neck diameter (P < .05), calcification (P < .01), and morphology (P = .002) as preexisting risk factors for postsurgical complications and neurological deterioration at discharge. Furthermore, intraoperative aneurysm rupture (odds ratio 2.863 [CI 1.606-5.104]; P < .01) and simultaneous clipping of more than 1 aneurysm (odds ratio 1.738 [CI 1.186-2.545]; P < .01) were shown to be associated with an increased risk of postsurgical complications. Yet, none of the surgical-related parameters had an impact on neurological deterioration. Analyzing volume-outcome relationship revealed comparable complication rates (P = .61) among all 15 participating centers. CONCLUSION: Our international, multicenter analysis presents current microsurgical treatment practices in patients with anterior circulation aneurysms and identifies preexisting and surgery-related risk factors for postoperative complications and neurological deterioration. These findings may assist in decision-making for the optimal therapeutic regimen of unruptured anterior circulation aneurysms.

Surgical management of stylocarotid Eagle syndrome in a patient with bilateral internal carotid artery dissection: illustrative case.

BACKGROUND: Eagle syndrome is characterized by an elongated styloid process, which can cause acute neurological symptoms when the projection impinges on local structures. One method by which Eagle syndrome can cause acute stroke is via internal carotid artery dissection. OBSERVATIONS: A patient presented with acute aphasia and right-arm weakness. Imaging revealed a left internal carotid artery dissection, which was treated with stenting. Three years later, the patient presented with left-sided weakness, and imaging revealed a new right internal carotid artery dissection. Closer review of the patient's imaging revealed bilateral elongated styloid processes. The patient subsequently underwent staged bilateral styloidectomy and returned to his prior baseline postoperatively. LESSONS: This case report describes a patient with Eagle syndrome who had two internal carotid artery dissections separated by several years. A literature review revealed that styloidectomy is well tolerated in patients with carotid dissection due to Eagle syndrome. Patients with carotid dissection due to Eagle syndrome remain at risk for contralateral dissection, and prophylactic contralateral styloidectomy should be considered.

Global Outcomes for Microsurgical Clipping of Unruptured Intracranial Aneurysms: A Benchmark Analysis of 2245 Cases.

BACKGROUND AND OBJECTIVES: Benchmarks represent the best possible outcome and help to improve outcomes for surgical procedures. However, global thresholds mirroring an optimal and reachable outcome for microsurgical clipping of unruptured intracranial aneurysms (UIA) are not available. This study aimed to define standardized outcome benchmarks in patients who underwent clipping of UIA. METHODS: A total of 2245 microsurgically treated UIA from 15 centers were analyzed. Patients were categorized into low- ("benchmark") and high-risk ("nonbenchmark") patients based on known factors affecting outcome. The benchmark was defined as the 75th percentile of all centers' median scores for a given outcome. Benchmark outcomes included intraoperative (eg, duration of surgery, blood transfusion), postoperative (eg, reoperation, neurological status), and aneurysm-related factors (eg, aneurysm occlusion). Benchmark cutoffs for aneurysms of the anterior communicating/anterior cerebral artery, middle cerebral artery, and posterior communicating artery were determined separately. RESULTS: Of the 2245 cases, 852 (37.9%) patients formed the benchmark cohort. Most operations were performed for middle cerebral artery aneurysms (53.6%), followed by anterior communicating and anterior cerebral artery aneurysms (25.2%). Based on the results of the benchmark cohort, the following benchmark cutoffs were established: favorable neurological outcome (modified Rankin scale ≤2) ≥95.9%, postoperative complication rate ≤20.7%, length of postoperative stay ≤7.7 days, asymptomatic stroke ≤3.6%, surgical site infection ≤2.7%, cerebral vasospasm ≤2.5%, new motor deficit ≤5.9%, aneurysm closure rate ≥97.1%, and at 1-year follow-up: aneurysm closure rate ≥98.0%. At 24 months, benchmark patients had a better score on the modified Rankin scale than nonbenchmark patients. CONCLUSION: This study presents internationally applicable benchmarks for clinically relevant outcomes after microsurgical clipping of UIA. These benchmark cutoffs can serve as reference values for other centers, patient registries, and for comparing the benefit of other interventions or novel surgical techniques.

Tenzing 7 delivery catheter with or without a leading microwire for single pass aspiration thrombectomy: A multicenter experience.

INTRODUCTION: Aspiration mechanical thrombectomy traditionally includes use of an inner microcatheter and leading microwire to navigate an aspiration catheter (AC) to the site of occlusion. Early clinical experience suggests that a leading microwire is often not needed with the Tenzing 7 (T7, Route 92 Medical, San Mateo, CA), a soft tapered tip ledge-reducing delivery catheter. This multicenter experience aims to describe AC delivery success in single-pass thrombectomy using T7 with and without a leading microwire. METHODS: A retrospective review was conducted of consecutive patients who underwent single-pass thrombectomy with T7 at six institutions between 2020 and 2022. We examined the percentage of successful AC delivery, puncture-to-revascularization time, and procedural complication rate. RESULTS: A leading microwire with T7 was used in 19/89 (21%) of patients, and it was not used with T7 in 70/89 (79%) of patients. Successful AC delivery was similar with and without microwires (97% vs. 90%, p = 0.15). Median puncture-to-revascularization times were similar (17 min microwire vs. 16 min no-microwire, p = 0.12). No complications were associated with microwire use; one (1.4%) patient had a T7-related vasospasm resolved with verapamil during thrombectomy without a leading microwire. Differences in complication rates were not statistically significant (p = 0.46). CONCLUSION: In our real-world clinical experience, leading microwire use was infrequently necessary with the T7 delivery catheter. Successful AC delivery and complication rates were similar with and without microwire use in single-pass T7 thrombectomies. Initial pass with T7 may be performed without use of leading microwire, reserving microwire use for refractory cases or known difficult-to-navigate vasculature.

Standalone middle meningeal artery embolization versus middle meningeal artery embolization with concurrent surgical evacuation for chronic subdural hematomas: a multicenter propensity score matched analysis of clinical and radiographic outcomes.

BACKGROUND: Middle meningeal artery embolization (MMAE) has emerged as a promising therapy for chronic subdural hematomas (cSDHs). The efficacy of standalone MMAE compared with MMAE with concurrent surgery is largely unknown. METHODS: cSDH patients who underwent successful MMAE from 14 high volume centers with at least 30 days of follow-up were included. Clinical and radiographic variables were recorded and used to perform propensity score matching (PSM) of patients treated with standalone MMAE or MMAE with concurrent surgery. Multivariable logistic regression models were used for additional covariate adjustments. The primary outcome was recurrence requiring surgical rescue, and the secondary outcome was radiographic failure defined as <50% reduction of cSDH thickness. RESULTS: 722 MMAE procedures in 588 cSDH patients were identified. After PSM, 230 MMAE procedures remained (115 in each group). Median age was 73 years, 22.6% of patients were receiving anticoagulation medication, and 47.9% had no preoperative functional disability. Median midline shift was 4 mm and cSDH thickness was 16 mm, representing modestly sized cSDHs. Standalone MMAE and MMAE with surgery resulted in similar rates of surgical rescue (7.8% vs 13.0%, respectively, P=0.28; adjusted OR (aOR 0.73 (95% CI 0.20 to 2.40), P=0.60) and radiographic failure (15.5% vs 13.7%, respectively, P=0.84; aOR 1.08 (95% CI 0.37 to 2.19), P=0.88) with a median follow-up duration of 105 days. These results were similar across subgroup analyses and follow-up durations. CONCLUSIONS: Standalone MMAE led to similar and durable clinical and radiographic outcomes as MMAE combined with surgery in select patients with moderately sized cSDHs and mild clinical disease.

Single center experience using 3†mm trevo stent retrievers in medium vessel occlusion thrombectomy.

BACKGROUND: Endovascular mechanical thrombectomy has been shown to benefit select patients with acute ischemic stroke caused by medium vessel occlusion, aided by recent advancements in endovascular mechanical thrombectomy devices that facilitate navigation through narrower vasculature. In this study, we aim to evaluate the safety and efficacy of using the 3 mm Trevo NXT stent retriever (Stryker, Kalamazoo, MI) for endovascular mechanical thrombectomy in patients with acute ischemic stroke caused by medium vessel occlusion. METHODS: From our single-center registry, we performed a retrospective review of all acute ischemic stroke patients from 2018 to 2022 who underwent endovascular mechanical thrombectomy for medium vessel occlusion with a 3 mm Trevo NXT. We examined efficacy outcomes (modified thrombolysis in cerebral infarction and puncture-to-revascularization time), clinical outcomes (National Institutes of Health Stroke Scale), and procedural complication rate. RESULTS: Between 2018 and 2022, 44 patients (52.2% female, mean age 71.1 years, median National Institutes of Health Stroke Scale of 15 [8-22.8]) met our inclusion criteria. The 3 mm Trevo NXT was used in the first pass in 56.9% of individuals, with 72.4% achieving successful recanalization (modified thrombolysis in cerebral infarction ≥ 2B). The 3 mm Trevo NXT was used as "rescue" after initial revascularization failure in 43.1% of individuals, achieving successful recanalization in 60.0% of passes. Acute complications were reported in 2.4% of cases. Median National Institutes of Health Stroke Scale at 24 h after intervention was 12 (4-20.8). CONCLUSIONS: Our results suggest that endovascular mechanical thrombectomy using the 3 mm Trevo NXT is a safe and effective treatment option for medium vessel occlusion. The utility of novel stent retrievers in the treatment of medium vessel occlusion should be further explored in future multicenter studies.

Common Carotid-Greater Saphenous-M2 Bypass for Myoepithelial Carcinoma Encasing the Carotid Artery.

Revascularization of the anterior circulation using a high-capacitance graft is sometimes necessary for treatment of cervical tumors encasing the internal carotid artery (ICA). In this surgical video, we aim to demonstrate the technical nuances of high-flow extra-to-intracranial bypass using a saphenous vein graft. The patient is a 23-year-old female who presented with a 4-month history of an enlarging left-sided neck mass, dysphagia, and 25-lb weight loss. Computed tomography and magnetic resonance imaging demonstrated an enhancing lesion encasing the cervical ICA. The patient underwent an open biopsy that established a diagnosis of a myoepithelial carcinoma. The patient was advised to undergo attempted gross total resection, which would require sacrifice of the cervical internal carotid artery. After the patient failed a balloon test occlusion of the left ICA, it was decided to perform a cervical ICA to middle cerebral artery M2 bypass using a saphenous vein graft, followed by tumor resection in staged fashion. Postoperative imaging demonstrated complete tumor removal and filling of the left anterior circulation via the saphenous vein graft. Video 1 discusses important preoperative and postoperative considerations, as well as highlights the technical nuances of this complex procedure. High-flow ICA to middle cerebral artery bypass using a saphenous vein graft can be employed to facilitate gross total resection of malignant tumors encasing the cervical internal carotid artery.

Safety and efficacy of the Pipeline Flex embolization device with Shield Technology for the acute treatment of ruptured internal carotid artery pseudoaneurysms: a multi-institution case series.

OBJECTIVE: Ruptured blister, dissecting, and iatrogenic pseudoaneurysms are rare pathologies that pose significant challenges from a treatment standpoint. Endovascular treatment via flow diversion represents an increasingly popular option; however, drawbacks include the requirement for dual antiplatelet therapy and the potential for thromboembolic complications, particularly acute complications in the ruptured setting. The Pipeline Flex embolization device with Shield Technology (PED-Shield) offers reduced material thrombogenicity, which may aid in the treatment of ruptured internal carotid artery pseudoaneurysms. METHODS: The authors conducted a multi-institution, retrospective case series to determine the safety and efficacy of PED-Shield for the treatment of ruptured blister, dissecting, and iatrogenic pseudoaneurysms of the internal carotid artery. Clinical, radiographic, treatment, and outcomes data were collected. RESULTS: Thirty-three patients were included in the final analysis. Seventeen underwent placement of a single device, and 16 underwent placement of two devices. No thromboembolic complications occurred. Four patients were maintained on aspirin alone, and all others were treated with long-term dual antiplatelet therapy. Among patients with 3-month follow-up, 93.8% had a modified Rankin Scale score of 0-2. Complete occlusion at follow-up was observed in 82.6% of patients. CONCLUSIONS: PED-Shield represents a new option for the treatment of ruptured blister, dissecting, and iatrogenic pseudoaneurysms of the internal carotid artery. The reduced material thrombogenicity appeared to improve the safety of the PED-Shield device, as this series demonstrated no thromboembolic complications even among patients treated with only single antiplatelet therapy. The efficacy of PED-Shield reported in this series, particularly with placement of two devices, demonstrates its potential as a first-line treatment option for these pathologies.

Bibliometric Analysis of the Top 100 Cited Articles on Stereotactic Radiosurgery for Trigeminal Neuralgia.

Background Stereotactic radiosurgical rhizolysis of the trigeminal nerve is an established modality increasingly employed to alleviate the symptoms of refractory trigeminal neuralgia. This study analyzes the academic impact of the top 100 cited articles on the radiosurgical management of trigeminal neuralgia. Methods The Scopus database was searched for articles containing "radiosurgery" and one or more of "trigeminal neuralgia," "trigeminus neuralgia," and "tic douloureux." The top 100 articles written in English were arranged in descending order by citation count. Documents were evaluated for authors, publication year, journal and impact factor, total citations, nationality, study type, radiosurgical modality, and the affiliated institution. Quantitative and qualitative analyses were performed on the data. Results The most cited articles were published between 1971 and 2019. The average citation per year was 4.3. The most targeted anatomic area was the "root entry zone" or proximal portion of the cisternal segment of the trigeminal nerve. The most utilized modality was Gamma Knife radiosurgery. The country with the highest number of publications was the United States. Thirty-six percent of the articles were published in the Journal of Neurosurgery . Lunsford, Kondziolka, Flickinger, and Régis, respectively, were the most frequently listed co-authors. The most prolific institute was the University of Pittsburgh Medical Center. Conclusion Stereotactic radiosurgery is an important modality in the management of medically or surgically refractory trigeminal neuralgia. This analysis assesses its contributions over the past five decades to identify trends in treatment practices for neurosurgeons and to highlight areas where further study is needed.

Middle Meningeal Artery Embolization for Chronic Subdural Hematoma: A Review.

Middle meningeal artery embolization (MMAE) for chronic subdural hematomas (cSDHs) has evolved as a potential treatment alternative for these lesions. The indications for using this treatment modality and the pathophysiology of cSDHs are an area of considerable interest. A retrospective review was performed including all major papers addressing this topic. Although considered a relatively new treatment option, MMAE for cSDHs is gaining widespread popularity. There are many questions that need to be addressed regarding its indications, some of which are the subject of ongoing clinical trials. The efficacy of this treatment modality in carefully selected patients has also provided new insights into the potential pathophysiology of cSDHs. This concise review will focus on the current evidence supporting the use of embolization in the treatment of this disease and highlight unanswered relevant clinical questions regarding MMAE indications and technique.

Microsurgical Obliteration of Craniocervical Junction Dural Arteriovenous Fistulas: Multicenter Experience.

BACKGROUND: Dural arteriovenous fistulas (dAVFs) located at craniocervical junction are extremely rare (1%-2% of intracranial/spinal dAVFs). Their angio-architectural complexity renders endovascular embolization to be challenging given multiple small feeders with risk of embolysate reflux into vertebral artery and limited transvenous access. The available literature discussing microsurgery for these lesions is limited to few case reports. OBJECTIVE: To report a multicenter experience assessing microsurgery safety/efficacy. METHODS: Prospectively maintained registries at 13 North American centers were queried to identify craniocervical junction dAVFs treated with microsurgery (2006-2021). RESULTS: Thirty-eight patients (median age 59.5 years, 44.7% female patients) were included. The most common presentation was subarachnoid/intracranial hemorrhage (47.4%) and myelopathy (36.8%) (92.1% of lesions Cognard type III-V). Direct meningeal branches from V3/4 vertebral artery segments supplied 84.2% of lesions. All lesions failed (n = 5, 13.2%) or were deemed inaccessible/unsafe to endovascular treatment. Far lateral craniotomy was the most used approach (94.7%). Intraoperative angiogram was performed in 39.5% of the cases, with angiographic cure in 94.7% of cases (median imaging follow-up of 9.2 months) and retreatment rate of 5.3%. Favorable last follow-up modified Rankin Scale of 0 to 2 was recorded in 81.6% of the patients with procedural complications of 2.6%. CONCLUSION: Craniocervical dAVFs represent rare entity of lesions presenting most commonly with hemorrhage or myelopathy because of venous congestion. Microsurgery using a far lateral approach provides robust exposure and visualization for these lesions and allows obliteration of the arterialized draining vein intradurally as close as possible to the fistula point. This approach was associated with a high rate of angiographic cure and favorable clinical outcomes.

Radiographic and clinical outcomes with particle or liquid embolic agents for middle meningeal artery embolization of nonacute subdural hematomas.

BACKGROUND: Middle meningeal artery (MMA) embolization is an apparently efficacious minimally invasive treatment for nonacute subdural hematomas (NASHs), but how different embolisates affect outcomes remains unclear. Our objective was to compare radiographic and clinical outcomes after particle or liquid MMA embolization. METHODS: Patients who had MMA embolization for NASH were retrospectively identified from a multi-institution database. The primary radiographic and clinical outcomes-50% NASH thickness reduction and need for surgical retreatment within 90 days, respectively-were compared for liquid and particle embolizations in patients treated 1) without surgical intervention (upfront), 2) after recurrence, or 3) with concomitant surgery (prophylactic). RESULTS: The upfront, recurrent, and prophylactic subgroups included 133, 59, and 16 patients, respectively. The primary radiographic outcome was observed in 61.8%, 61%, and 72.7% of particle-embolized patients and 61.3%, 55.6%, and 20% of liquid-embolized patients, respectively (p = 0.457, 0.819, 0.755). Hazard ratios comparing time to reach radiographic outcome in the particle and liquid groups or upfront, recurrent, andprophylactic timing were 1.31 (95% CI 0.78-2.18; p = 0.310), 1.09 (95% CI 0.52-2.27; p = 0.822), and 1.5 (95% CI 0.14-16.54; p = 0.74), respectively. The primary clinical outcome occurred in 8.0%, 2.4%, and 0% of patients who underwent particle embolization in the upfront, recurrent, and prophylactic groups, respectively, compared with 0%, 5.6%, and 0% who underwent liquid embolization (p = 0.197, 0.521, 1.00). CONCLUSIONS: MMA embolization with particle and liquid embolisates appears to be equally effective in treatment of NASHs as determined by the percentage who reach, and the time to reach, 50% NASH thickness reduction and the incidence of surgical reintervention within 90 days.

Bibliometric analysis of the top 100 cited articles on stereotactic radiosurgery of intracranial meningiomas.

BACKGROUND: Sterotactic radiosurgery is becoming an integral modality in the management of intracranial meningiomas, both as the primary treatment or as adjuvant therapy. This study analyzes the scholarly impact of the top 100 cited articles on the stereotactic radiosurgical management of intracranial meningiomas. METHODS: A ranked list of the 100 most-cited articles was generated using the Scopus database by searching the keywords 'intracranial meningioma' and 'stereotactic radiosurgery'. All articles were then evaluated on multiple criteria regarding both the publication of the articles (year of publication, journal, country of origin, and authors) as well as their methods and foci (type of study, location of studied meningiomas, and type of radiosurgical modality). Quantitaitve and qualitative analyses were then performed from the collected data. RESULTS: The most frequently cited articles on stereotactic radiosurgical management of intracranial meningiomas were published between 1990 and 2016. The average citation-per-year across all papers in the list was 6.1. The most studied anatomic area of intracranial meningiomas was the skull base, with the cavernous sinus being the most well-studied specific site. The most utilized stereotactic radiosurgical modality was Gamma Knife radiosurgery. The country with the highest number of publications was the United States. Twenty-six percent of the articles were published in the journal Neurosurgery; Lunsford, Kondziolka, Flickinger, Sheehan, and Pollock were respectively the most frequent listed authors among this list. The most active academic institute publishing on this topic was the University of Pittsburgh Medical Center. CONCLUSION: Stereotactic radiosurgery is an integral modality in the management of intracranial meningiomas. This bibliometric analysis sheds the light on the ways in which intracranial meningiomas have been studied in the past two decades in order to identify trends among neurosurgeons and radiation oncologists and to reveal areas of rising and declining focus.