Neutrophils and Neutrophil Extracellular Traps Cause Vascular Occlusion and Delayed Cerebral Ischemia After Subarachnoid Hemorrhage in Mice.

BACKGROUND: After subarachnoid hemorrhage (SAH), neutrophils are deleterious and contribute to poor outcomes. Neutrophils can produce neutrophil extracellular traps (NETs) after ischemic stroke. Our hypothesis was that, after SAH, neutrophils contribute to delayed cerebral ischemia (DCI) and worse outcomes via cerebrovascular occlusion by NETs. METHODS: SAH was induced via endovascular perforation, and SAH mice were given either a neutrophil-depleting antibody, a PAD4 (peptidylarginine deiminase 4) inhibitor (to prevent NETosis), DNAse-I (to degrade NETs), or a vehicle control. Mice underwent daily neurological assessment until day 7 and then euthanized for quantification of intravascular brain NETs (iNETs). Subsets of mice were used to quantify neutrophil infiltration, NETosis potential, iNETs, cerebral perfusion, and infarction. In addition, NET markers were assessed in the blood of aneurysmal SAH patients. RESULTS: In mice, SAH led to brain neutrophil infiltration within 24 hours, induced a pro-NETosis phenotype selectively in skull neutrophils, and caused a significant increase in iNETs by day 1, which persisted until at least day 7. Neutrophil depletion significantly reduced iNETs, improving cerebral perfusion, leading to less neurological deficits and less incidence of DCI (16% versus 51.9%). Similarly, PAD4 inhibition reduced iNETs, improved neurological outcome, and reduced incidence of DCI (5% versus 30%), whereas degrading NETs marginally improved outcomes. Patients with aneurysmal SAH who developed DCI had elevated markers of NETs compared with non-DCI patients. CONCLUSIONS: After SAH, skull-derived neutrophils are primed for NETosis, and there are persistent brain iNETs, which correlated with delayed deficits. The findings from this study suggest that, after SAH, neutrophils and NETosis are therapeutic targets, which can prevent vascular occlusion by NETs in the brain, thereby lessening the risk of DCI. Finally, NET markers may be biomarkers, which can predict which patients with aneurysmal SAH are at risk for developing DCI.

Cerebrovascular Complications Associated With Iatrogenic Fungal Meningitis Following Surgical Procedures in Mexico.

BACKGROUND: The current fungal meningitis outbreak caused by contaminated epidural anesthesia with Fusarium solani among patients who underwent surgical procedures in Matamoros, Mexico remains a cause of concern. Its association with an increased susceptibility for cerebrovascular complications (CVC) has not been reported. This single-center study describes 3 patients with a unique pattern of CVC attributed to fungal meningitis. METHODS: A retrospective case series of patients diagnosed with fungal meningitis following surgical procedures under contaminated epidural anesthesia who developed a unique pattern of CVC during their hospitalization. RESULTS: Three female patients (mean age, 35 years) with CVC due to iatrogenic fungal meningitis were included. Positive Fungitell ß-D-glucan assay in cerebrospinal fluid was documented in all cases, and F. solani was confirmed by polymerase chain reaction in case 3. All cases were complicated by severe vertebrobasilar circulation vasculopathy and arterial dissections with resultant subarachnoid hemorrhage and intraventricular hemorrhage, ultimately leading to patients' death. CONCLUSIONS: The death toll from the ongoing fungal meningitis outbreak keeps rising, underscoring the need for early recognition and aggressive treatment. We highlight the risk for vertebrobasilar circulation CVC among these patients. The angioinvasive nature of F. solani is yet to be clarified; however, a clear pattern has been observed. Public health awareness should be raised and a strong response should be pursued.

Endothelial TLR4 and the microbiome drive cerebral cavernous malformations.

Cerebral cavernous malformations (CCMs) are a cause of stroke and seizure for which no effective medical therapies yet exist. CCMs arise from the loss of an adaptor complex that negatively regulates MEKK3-KLF2/4 signalling in brain endothelial cells, but upstream activators of this disease pathway have yet to be identified. Here we identify endothelial Toll-like receptor 4 (TLR4) and the gut microbiome as critical stimulants of CCM formation. Activation of TLR4 by Gram-negative bacteria or lipopolysaccharide accelerates CCM formation, and genetic or pharmacologic blockade of TLR4 signalling prevents CCM formation in mice. Polymorphisms that increase expression of the TLR4 gene or the gene encoding its co-receptor CD14 are associated with higher CCM lesion burden in humans. Germ-free mice are protected from CCM formation, and a single course of antibiotics permanently alters CCM susceptibility in mice. These studies identify unexpected roles for the microbiome and innate immune signalling in the pathogenesis of a cerebrovascular disease, as well as strategies for its treatment.

Utility of Surveillance Angiography in Aneurysmal Subarachnoid Hemorrhage: A Retrospective Study of 223 Consecutive Patients.

BACKGROUND: Patients with aneurysmal subarachnoid hemorrhage (aSAH) who survive the rupture are at risk for delayed neurologic deficits and cerebral infarction. The ideal method(s) of surveillance for cerebral vasospasm, and the link between radiographic vasospasm and delayed neurologic deficits, remain controversial. We instituted a postbleed day 7 angiography protocol with the stated goals of identification of vasospasm, improving neurologic outcomes, and possibly lowering cost of care. METHODS: We conducted a quality improvement project in which we retrospectively analyzed consecutive cases of aSAH from a single institution over a 5-year period. Patients were excluded if they did not receive treatment for their aneurysm or were < 18 years of age. We analyzed demographic and outcome information for patients managed by protocolled angiography versus those who were managed by as-needed endovascular rescue therapy. Statistical tests were performed comparing means and proportions in both cohorts, as appropriate. RESULTS: In total, 223 patients were identified who met inclusion criteria. In total, 157 patients were identified in the protocolled day 7 angiography group, and 66 were in the nonprotocolled angiography group. Demographics were similar between the day 7 angiogram and medical management cohorts, except for a higher mean age among the latter group (p = 0.016). The protocolled angiography group underwent a significantly greater number of angiograms (p < 0.001) and had a significantly higher cost of hospitalization ($240,327 vs. $205,719, p = 0.03), with no significant difference in rate of cerebral infarction, length of intensive care unit stay, length of hospital stay, discharge location, or discharge modified Rankin Score. CONCLUSIONS: This cohort comparison analysis draws into question the practice of protocolized cerebral angiography in patients with aSAH.

Subarachnoid Blood Clearance and Aneurysmal Subarachnoid Hemorrhage Outcomes: A Retrospective Review.

BACKGROUND: Delayed cerebral ischemia (DCI) continues to be a significant contributor to morbidity and mortality following aneurysmal subarachnoid hemorrhage (aSAH). Subarachnoid blood and its degradation products have been implicated in DCI, and faster blood clearance has been hypothesized to confer better outcomes. This study evaluates the relationship between blood volume and its clearance on DCI (primary outcome) and location at 30 days (secondary outcome) after aSAH. METHODS: This is a retrospective review of adult patients presenting with aSAH. Hijdra sum scores (HSS) were assessed independently for each computed tomography (CT) scan of patients with available scans on post-bleed days 0-1 and 2-10. This cohort was used to evaluate the course of subarachnoid blood clearance (group 1). A subset of patients in the first cohort with available CT scans on both post-bleed days 0-1 and post-bleed days 3-4 composed the second cohort (group 2). This group was used to evaluate the association between initial subarachnoid blood (measured via HSS post-bleed days 0-1) and its clearance (measured via percentage reduction [HSS %Reduction] and absolute reduction [HSS-Abs-Reduction] in HSS between days 0-1 and 3-4) on outcomes. Univariable and multivariable logistic regression models were used to identify outcome predictors. RESULTS: One hundred fifty-six patients were in group 1, and 72 patients were in group 2. In this cohort, HSS %Reduction was associated with decreased risk of DCI in univariate (odds ratio [OR] = 0.700 [0.527-0.923], p = 0.011) and multivariable (OR = 0.700 [0.527-0.923], p = 0.012) analyses. Higher HSS %Reduction was significantly more likely to have better outcomes at 30 days in the multivariable analysis (OR = 0.703 [0.507-0.980], p = 0.036). Initial subarachnoid blood volume was associated with outcome location at 30 days (OR = 1.331 [1.040-1.701], p = 0.023) but not DCI (OR = 0.945 [0.780-1.145], p = 0.567). CONCLUSIONS: Early blood clearance after aSAH was associated with DCI (univariable and multivariable analyses) and outcome location at 30 days (multivariable analysis). Methods facilitating subarachnoid blood clearance warrant further investigation.

Glyoxal Fixation Is Optimal for Immunostaining of Brain Vessels, Pericytes and Blood-Brain Barrier Proteins.

Brain vascular staining is very important for understanding cerebrovascular pathologies. 4% paraformaldehyde is considered the gold standard fixation technique for immunohistochemistry and it revolutionized the examination of proteins in fixed tissues. However, this fixation technique produces inconsistent immunohistochemical staining results due to antigen masking. Here, we test a new fixation protocol using 3% glyoxal and demonstrate that this method improves the staining of the brain vasculature, pericytes, and tight junction proteins compared to 4% paraformaldehyde. Use of this new fixation technique will provide more detailed information about vascular protein expressions, their distributions, and colocalizations with other proteins at the molecular level in the brain vasculature.

Plasma Biomarkers of Inflammation and Angiogenesis Predict Cerebral Cavernous Malformation Symptomatic Hemorrhage or Lesional Growth.

RATIONALE: The clinical course of cerebral cavernous malformations is highly unpredictable, with few cross-sectional studies correlating proinflammatory genotypes and plasma biomarkers with prior disease severity. OBJECTIVE: We hypothesize that a panel of 24 candidate plasma biomarkers, with a reported role in the physiopathology of cerebral cavernous malformations, may predict subsequent clinically relevant disease activity. METHODS AND RESULTS: Plasma biomarkers were assessed in nonfasting peripheral venous blood collected from consecutive cerebral cavernous malformation subjects followed for 1 year after initial sample collection. A first cohort (N=49) was used to define the best model of biomarker level combinations to predict a subsequent symptomatic lesional hemorrhagic expansion within a year after the blood sample. We generated the receiver operating characteristic curves and area under the curve for each biomarker individually and each weighted linear combination of relevant biomarkers. The best model to predict lesional activity was selected as that minimizing the Akaike information criterion. In this cohort, 11 subjects experienced symptomatic lesional hemorrhagic expansion (5 bleeds and 10 lesional growths) within a year after the blood draw. Subjects had lower soluble CD14 (cluster of differentiation 14; P=0.05), IL (interleukin)-6 (P=0.04), and VEGF (vascular endothelial growth factor; P=0.0003) levels along with higher plasma levels of IL-1ß (P=0.008) and soluble ROBO4 (roundabout guidance receptor 4; P=0.03). Among the 31 weighted linear combinations of these 5 biomarkers, the best model (with the lowest Akaike information criterion value, 25.3) was the weighted linear combination including soluble CD14, IL-1ß, VEGF, and soluble ROBO4, predicting a symptomatic hemorrhagic expansion with a sensitivity of 86% and specificity of 88% (area under the curve, 0.90; P<0.0001). We then validated our best model in the second sequential independent cohort (N=28). CONCLUSIONS: This is the first study reporting a predictive association between plasma biomarkers and subsequent cerebral cavernous malformation disease clinical activity. This may be applied in clinical prognostication and stratification of cases in clinical trials.

Phenotypic characterization of murine models of cerebral cavernous malformations.

Cerebral cavernous malformations (CCMs) are clusters of dilated capillaries that affect around 0.5% of the population. CCMs exist in two forms, sporadic and familial. Mutations in three documented genes, KRIT1(CCM1), CCM2, and PDCD10(CCM3), cause the autosomal dominant form of the disease, and somatic mutations in these same genes underlie lesion development in the brain. Murine models with constitutive or induced loss of respective genes have been applied to study disease pathobiology and therapeutic manipulations. We aimed to analyze the phenotypic characteristic of two main groups of models, the chronic heterozygous models with sensitizers promoting genetic instability, and the acute neonatal induced homozygous knockout model. Acute model mice harbored a higher lesion burden than chronic models, more localized in the hindbrain, and largely lacking iron deposition and inflammatory cell infiltrate. The chronic model mice showed a lower lesion burden localized throughout the brain, with significantly greater perilesional iron deposition, immune B- and T-cell infiltration, and less frequent junctional protein immunopositive endothelial cells. Lesional endothelial cells in both models expressed similar phosphorylated myosin light chain immunopositivity indicating Rho-associated protein kinase activity. These data suggest that acute models are better suited to study the initial formation of the lesion, while the chronic models better reflect lesion maturation, hemorrhage, and inflammatory response, relevant pathobiologic features of the human disease.

Quantitative susceptibility mapping as a monitoring biomarker in cerebral cavernous malformations with recent hemorrhage.

BACKGROUND: Quantitative Susceptibility Mapping (QSM) MRI allows accurate assessment of iron content in cerebral cavernous malformations (CCM), and a threshold increase by 6% in QSM has been shown to reflect new symptomatic hemorrhage (SH) in previously stable lesions. PURPOSE/HYPOTHESIS: It is unclear how lesional QSM evolves in CCMs after recent SH, and whether this could serve as a monitoring biomarker in clinical trials aimed at preventing rebleeding in these lesions. STUDY TYPE: This is a prospective observational cohort study. POPULATION: 16 CCM patients who experienced a SH within the past year, whose lesion was not resected or irradiated. FIELD STRENGTH/SEQUENCE: The data acquisition was performed using QSM sequence implemented on a 3T MRI system ASSESSMENT: The lesional QSM assessments at baseline and yearly during 22 patient-years of follow-up were performed by a trained research staff including imaging scientists. STATISTICAL TESTS: Biomarker changes were assessed in relation to clinical events. Clinical trial modeling was performed using two-tailed tests of time-averaged difference (assuming within-patient correlation of 0.8, power = 0.9 and alpha = 0.1) to detect 20%, 30% or 50% effects of intervention on clinical and biomarkers event rates during two years of follow-up. RESULTS: The change in mean lesional QSM of index hemorrhagic lesions was +7.93% per patient-year in the whole cohort. There were 5 cases (31%) of recurrent SH or lesional growth, and twice as many instances (62%) with a threshold (6%) increase in QSM. There were no instances of SH hemorrhage or lesional growth without an associated threshold increase in QSM during the same epoch. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 4 J. Magn. Reson. Imaging 2018;47:1133-1138.

RhoA Kinase Inhibition With Fasudil Versus Simvastatin in Murine Models of Cerebral Cavernous Malformations.

BACKGROUND AND PURPOSE: We sought to compare the effect of chronic treatment with commonly tolerated doses of Fasudil, a specific RhoA kinase (ROCK) inhibitor, and simvastatin (with pleiotropic effects including ROCK inhibition) on cerebral cavernous malformation (CCM) genesis and maturation in 2 models that recapitulate the human disease. METHODS: Two heterozygous murine models, Ccm1+/-Msh2-/- and Ccm2+/-Trp53-/-, were treated from weaning to 4 to 5 months of age with Fasudil (100 mg/kg per day), simvastatin (40 mg/kg per day) or with placebo. Mouse brains were blindly assessed for CCM lesion burden, nonheme iron deposition (as a quantitative measure of chronic lesional hemorrhage), and ROCK activity. RESULTS: Fasudil, but not simvastatin, significantly decreased mature CCM lesion burden in Ccm1+/-Msh2-/- mice, and in meta-analysis of both models combined, when compared with mice receiving placebo. Fasudil and simvastatin both significantly decreased the integrated iron density per mature lesion area in Ccm1+/-Msh2-/- mice, and in both models combined, compared with mice given placebo. ROCK activity in mature lesions of Ccm1+/-Msh2-/- mice was similar with both treatments. Fasudil, but not simvastatin, improved survival in Ccm1+/-Msh2-/- mice. Fasudil and simvastatin treatment did not affect survival or lesion development significantly in Ccm2+/-Trp53-/- mice alone, and Fasudil benefit seemed limited to males. CONCLUSIONS: ROCK inhibitor Fasudil was more efficacious than simvastatin in improving survival and blunting the development of mature CCM lesions. Both drugs significantly decreased chronic hemorrhage in CCM lesions. These findings justify the development of ROCK inhibitors and the clinical testing of commonly used statin agents in CCM.

Demographic Risk Factors for Vascular Lesions as Etiology of Intraventricular Hemorrhage in Prospectively Screened Cases.

BACKGROUND: Spontaneous intraventricular hemorrhage (IVH) is associated with high rates of morbidity and mortality despite critical care and other advances. An important step in clinical management is to confirm/rule out an underlying vascular lesion, which influences further treatment, potential for further bleeding, and prognosis. Our aim is to compare demographic and clinical characteristics between IVH patients with and without an underlying vascular lesion, and among cohorts with different vascular lesions. METHODS: We analyzed prospectively collected data of IVH patients screened for eligibility as part of the Clot Lysis: Evaluation Accelerated Resolution of IVH Phase III (CLEAR III) clinical trial. The trial adopted a structured screening process to systematically exclude patients with an underlying vascular lesion as the etiology of IVH. We collected age, sex, ethnicity, and primary diagnosis on these cases and vascular lesions were categorized prospectively as aneurysm, vascular malformation (arteriovenous malformation, dural arteriovenous fistula, and cavernoma), Moyamoya disease, or other vascular lesion. We excluded cases <18 or >80 years of age. Baseline characteristics were compared between the CLEAR group (IVH screened without vascular lesion) and the group of IVH patients screened and excluded from CLEAR because of an identified vascular lesion. We further analyzed the differential demographic and clinical characteristics among subcohorts with different vascular lesions. RESULTS: A total of 10,538 consecutive IVH cases were prospectively screened for the trial between 2011 and 2015. Out of these, 496 cases (4.7%) screened negative for underlying vascular lesion, met the inclusion criteria, and were enrolled in the trial (no vascular etiology group); and 1,205 cases (11.4%) were concurrently screened and excluded from the trial because of a demonstrated underlying vascular lesion (vascular etiology group). Cases with vascular lesion were less likely to be >45 years of age (OR 0.28, 95% CI 0.20-0.40), African-American (OR 0.23, 95% CI 0.18-0.31), or male gender (OR 0.48, 95% CI 0.38-0.60), and more likely to present with primary IVH (OR 1.85, 95% CI 1.37-2.51) compared to those with no vascular etiology (p < 0.001). Other demographic factors were associated with specific vascular lesion etiologies. A combination of demographic features increases the association with the absence of vascular lesion, but not with absolute reliability (OR 0.1, 95% CI 0.06-0.17, p < 0.001). CONCLUSION: An underlying vascular lesion as etiology of IVH cannot be excluded solely by demographic parameters in any patient. Some form of vascular imaging is necessary in screening patients before contemplating interventions like intraventricular fibrinolysis, where safety may be impacted by the presence of vascular lesion.

Intramuscular myxoma of the tibialis anterior muscle First report in the English literature.

Intramuscular myxoma is a rare entity in itself, and while it has been described in several locations in the body, its presence in the tibialis anterior muscle has only been reported once in the literature. In this case report, we present, to our knowledge, the first case of an intramuscular myxoma in the tibialis anterior muscle in the English literature, which was successfully managed with wide surgical resection.

Congenital vesicovaginal fistula: spontaneous or forced? Two cases and literature review.

INTRODUCTION AND HYPOTHESIS: Congenital vesicovaginal fistula is an exceedingly rare entity. There is no consensus regarding the nature and origin of this condition. We report two cases with congenital vesicovaginal fistula and compile previously reported cases in the English literature. Theories behind the genesis of this anomaly will be briefly presented. METHODS: We describe the presentation, diagnostic workup, and management of two patients with congenital vesicovaginal fistula. Previously reported cases were retrieved through an extensive English literature review using Medline and PubMed. Cases are tabulated based on the presence or absence of vaginal menstrual outflow obstruction. RESULTS: Two women, aged 23 and 17, had had cyclic hematuria since puberty that was perceived as normal menstruation. One woman presented with an inability to have sexual intercourse, and the other with severe cyclic pelvic pain. Diagnostic workup unveiled congenital vesicovaginal fistula and distal vaginal agenesis in both. One had abnormal ureteric insertion, while the other had a history of anomalies unrelated to the urogenital system. Successful surgical correction of fistula was undertaken in both. An English literature review revealed 23 reported cases of congenital vesicovaginal fistula. While 74 % had concomitant menstrual outflow obstruction, the remaining had normal menstruation per vagina. CONCLUSION: Congenital vesicovaginal fistula can present as an isolated anomaly, or associated with complex malformations of a wide spectrum. The presenting symptoms as well as the age at diagnosis vary widely. While the term "congenital" implies its genesis before birth, a congenital vesicovaginal fistula can be a manifestation of faulty embryological development, but also the result of outflow obstruction.

12/15-Lipooxygenase Inhibition Reduces Microvessel Constriction and Microthrombi after Subarachnoid Hemorrhage in Mice.

Background and Purpose: Impaired cerebral circulation, induced by blood vessel constrictions and microthrombi, leads to delayed cerebral ischemia after subarachnoid hemorrhage (SAH). 12/15-Lipooxygenase (12/15-LOX) overexpression has been implicated in worsening early brain injury outcomes following SAH. However, it is unknown if 12/15-LOX is important in delayed pathophysiological events after SAH. Since 12/15-LOX produces metabolites that induce inflammation and vasoconstriction, we hypothesized that 12/15-LOX leads to microvessel constriction and microthrombi formation after SAH, and thus 12/15-LOX is an important target to prevent delayed cerebral ischemia. Methods: SAH was induced in C57BL/6 and 12/15-LOX-/- mice of both sexes by endovascular perforation. Expression of 12/15-LOX was assessed in brain tissue slices and in vitro. C57BL/6 mice were administered either ML351 (12/15-LOX inhibitor) or vehicle. Mice were evaluated for daily neuroscore and euthanized on day five to assess cerebral 12/15-LOX expression, vessel constrictions, platelet activation, microthrombi, neurodegeneration, infarction, cortical perfusion, and for development of delayed deficits. Finally, the effect of 12/15-LOX inhibition on platelet activation was assessed in SAH patient samples using a platelet spreading assay. Results: In SAH mice, 12/15-LOX was upregulated in brain vascular cells and there was an increase in 12-S-HETE. Inhibition of 12/15-LOX improved brain perfusion on days 4-5 and attenuated delayed pathophysiological events, including microvessel constrictions, microthrombi, neuronal degeneration, and infarction. Additionally, 12/15-LOX inhibition reduced platelet activation in human and mouse blood samples. Conclusions: Cerebrovascular 12/15-LOX overexpression plays a major role in brain dysfunction after SAH by triggering microvessel constrictions and microthrombi formation, which reduces brain perfusion. Inhibiting 12/15-LOX may be a therapeutic target to improve outcomes after SAH.

Middle meningeal artery embolization reduces recurrence following surgery for septated chronic subdural hematomas.

BACKGROUND: Septated chronic subdural hematomas (cSDH) have high rates of recurrence despite surgical evacuation. Middle meningeal artery embolization (MMAE) has emerged as a promising adjuvant for secondary prevention, yet its efficacy remains ill-defined. METHODS: This is a retrospective review of septated cSDH cases treated at our institution. The surgery-only group was derived from cases performed before 2018, and the surgery+MMAE group was derived from cases performed 2018 or later. The primary outcome was reoperation rate. Secondary outcomes were recurrence, change in hematoma thickness, and midline shift. RESULTS: A total of 34 cSDHs in 28 patients (surgery+MMAE) and 95 cSDHs in 83 patients (surgery-only) met the inclusion criteria. No significant difference in baseline characteristics between groups was identified. The reoperation rate was significantly higher in the surgery-only group (n = 16, 16.8%) compared with the surgery+MMAE cohort (n = 0, 0.0%) (p=0.006). A reduced incidence of recurrence (p=0.011) was also seen in the surgery+MMAE group. CONCLUSIONS: MMAE for septated cSDH was found to be highly effective in preventing recurrence and reoperation. MMAE is an adjunct to surgical evacuation may be of particular benefit in this patient cohort.

Acute traumatic dural arteriovenous fistula of the superior sagittal sinus: illustrative case.

BACKGROUND: Dural arteriovenous fistulas (dAVFs) are aberrant vascular communications between meningeal arteries and venous sinuses or cortical veins. dAVF pathogenesis is incompletely understood; however, formation likely occurs as a result of angioneogensis. OBSERVATIONS: A 78-year-old man presented after trauma with basal and cortical subarachnoid hemorrhage (SAH). Computed tomography revealed a parietal bone fracture overlying the superior sagittal sinus (SSS). Catheter angiography performed within 24 hours of the injury demonstrated an SSS dAVF supplied by the middle meningeal artery, adjacent to the fracture. LESSONS: The authors present the case of an acute traumatic dAVF adjacent to a calvarial fracture. In this case, the authors proprose that the underlying pathogenesis is suggestive of direct vessel injury rather than the pathway commonly associated with this pathology.

Neurofibroma of the internal carotid artery cavernous sympathetic plexus: illustrative case.

BACKGROUND: Intracranial carotid sympathetic plexus (CSP) nerve sheath tumors have rarely been reported in the literature. This study describes the first reported case of a CSP neurofibroma and the first case of a CSP nerve sheath tumor treated via an endoscopic endonasal approach followed by adjuvant radiosurgery. OBSERVATIONS: A 53-year-old man presented with 3 days of headaches and diplopia and was found to have a complete left abducens nerve palsy. Computed tomography (CT) revealed a smoothly dilated left carotid canal, CT angiography revealed a superiorly displaced left internal carotid artery (ICA), and magnetic resonance imaging revealed a T2-hyperintense and avidly enhancing lesion in the left cavernous sinus encasing the ICA. The patient underwent subtotal resection via an endoscopic transsphenoidal transcavernous approach followed by Gamma Knife radiosurgery. LESSONS: Nerve sheath tumors arising from the CSP are extremely rare but need to be considered when assessing unusual cavernous sinus lesions. The clinical presentation is dependent on the anatomical location of the tumor and its relationship to the ICA. The optimal treatment paradigm is unknown.

Middle meningeal artery embolization of septated chronic subdural hematomas.

INTRODUCTION: Middle meningeal artery embolization (MMAE) has emerged as a promising new treatment for patients with chronic subdural hematomas (cSDH). Its efficacy, however, upon the subtype with a high rate of recurrence-septated cSDH-remains undetermined. METHODS: From our prospective registry of patients with cSDH treated with MMAE, we classified patients based on the presence or absence of septations. The primary outcome was the rate of recurrence of cSDH. Secondary outcomes included a reduction in cSDH thickness, midline shift, and rate of reoperation. RESULTS: Among 80 patients with 99 cSDHs, the median age was 68 years (IQR 59-77) with 20% females. Twenty-eight cSDHs (35%) had septations identified on imaging. Surgical evacuation with burr holes was performed in 45% and craniotomy in 18.8%. Baseline characteristics between no-septations (no-SEP) and septations (SEP) groups were similar except for median age (SEP vs no-SEP, 72.5 vs. 65.5, p = 0.016). The recurrence rate was lower in the SEP group (SEP vs. no-SEP, 3 vs. 16.7%, p = 0.017) with higher odds of response from MMAE for septated lesions even when controlling for evacuation strategy and antithrombotic use (OR = 0.06, CI [0.006-0.536], p = 0.012). MMAE resulted in higher mean absolute thickness reduction (SEP vs. no-SEP, -8.2 vs. -4.8 mm, p = 0.016) with a similar midline shift change. The rate of reoperation did not differ (6.2 vs. 3.1%, p = 0.65). CONCLUSION: MMAE appears to be equal to potentially more effective in preventing the recurrence of cSDH in septated lesions. These findings may aid in patient selection.

Middle Meningeal Artery Embolization for Chronic Subdural Hematomas With Concurrent Antithrombotics.

BACKGROUND: Chronic subdural hematoma (CSDH) is an increasingly prevalent disease in the aging population. Patients with CSDH frequently suffer from concurrent vascular disease or develop secondary thrombotic complications requiring antithrombotic treatment. OBJECTIVE: To determine the safety and impact of early reinitiation of antithrombotics after middle meningeal artery embolization for chronic subdural hematoma. METHODS: This is a single-institution, retrospective study of patients who underwent middle meningeal artery (MMA) embolizations for CSDH. Patient with or without antithrombotic initiation within 5 days postembolization were compared. Primary outcome was the rate of recurrence within 60 days. Secondary outcomes included rate of reoperation, reduction in CSDH thickness, and midline shift. RESULTS: Fifty-seven patients met inclusion criteria. The median age was 66 years (IQR 58-76) with 21.1% females. Sixty-six embolizations were performed. The median length to follow-up was 20 days (IQR 14-44). Nineteen patients (33.3%) had rapid reinitiation of antithrombotics (5 antiplatelet, 11 anticoagulation, and 3 both). Baseline characteristics between the no antithrombotic (no-AT) and the AT groups were similar. The recurrence rate was higher in the AT group (no-AT vs AT, 9.3 vs 30.4%, P = .03). Mean absolute reduction in CSDH thickness and midline shift was similar between groups. Rate of reoperation did not differ (4.7 vs 8.7%, P = .61). CONCLUSION: Rapid reinitiation of AT after MMA embolization for CSDH leads to higher rates of recurrence with similar rates of reoperation. Care must be taken when initiating antithrombotics after treatment of CSDH with MMA embolization.