Identifying important factors for successful surgery in patients with lateral temporal lobe epilepsy.

OBJECTIVE: Lateral temporal lobe epilepsy (LTLE) has been diagnosed in only a small number of patients; therefore, its surgical outcome is not as well-known as that of mesial temporal lobe epilepsy. We aimed to evaluate the long-term (5 years) and short-term (2 years) surgical outcomes and identify possible prognostic factors in patients with LTLE. METHODS: This retrospective cohort study was conducted between January 1995 and December 2018 among patients who underwent resective surgery in a university-affiliated hospital. Patients were classified as LTLE if ictal onset zone was in lateral temporal area. Surgical outcomes were evaluated at 2 and 5 years. We subdivided based on outcomes and compared clinical and neuroimaging data including cortical thickness between two groups. RESULTS: Sixty-four patients were included in the study. The mean follow-up duration after the surgery was 8.4 years. Five years after surgery, 45 of the 63 (71.4%) patients achieved seizure freedom. Clinically and statistically significant prognostic factors for postsurgical outcomes were the duration of epilepsy before surgery and focal cortical dysplasia on postoperative histopathology at the 5-year follow-up. Optimal cut-off point for epilepsy duration was eight years after the seizure onset (odds ratio 4.375, p-value = 0.0214). Furthermore, we propose a model for predicting seizure outcomes 5 years after surgery using the receiver operating characteristic curve and nomogram (area under the curve = 0.733; 95% confidence interval, 0.588-0.879). Cortical thinning was observed in ipsilateral cingulate gyrus and contralateral parietal lobe in poor surgical group compared to good surgical group (p-value < 0.01, uncorrected). CONCLUSIONS: The identified predictors of unfavorable surgical outcomes may help in selecting optimal candidates and identifying the optimal timing for surgery among patients with LTLE. Additionally, cortical thinning was more extensive in the poor surgical group.

Vessel Wall Changes on Serial High-Resolution MRI and the Use of Cilostazol in Patients With Adult-Onset Moyamoya Disease.

BACKGROUND AND PURPOSE: The natural course of adult-onset moyamoya disease (MMD) is unknown, and there is no medical treatment that halts its progression. We hypothesized that progressive shrinkage of large intracranial arteries occurs in adult-onset MMD, and that cilostazol inhibits this process. METHODS: Serial high-resolution magnetic resonance imaging (HR-MRI) was performed on 66 patients with MMD: 30 patients received cilostazol, 21 received other antiplatelets, and 15 received no antiplatelets or had poor compliance to them. Serial HR-MRI was performed (interval between MRI scans: 29.67±18.02 months, mean±SD), and changes in outer diameter, luminal stenosis, and vascular enhancement were measured. Factors affecting HR-MRI changes were evaluated, including vascular risk factors and the ring finger protein 213 gene variant. RESULTS: The progression of stenosis to occlusion, recurrent ischemic stroke, and the development of new stenotic segments were observed in seven, seven, and three patients, respectively. Serial HR-MRI indicated that the degree of stenosis increased with negative remodeling (outer diameter shrinkage). Patients who received cilostazol presented significantly larger outer diameters and lower degrees of stenosis compared with other groups (p=0.005 and p=0.031, respectively). After adjusting for clinical and genetic factors, only cilostazol use was independently associated with negative remodeling (odds ratio=0.29, 95% confidence interval=0.10-0.84, p=0.023). While vascular enhancement was observed in most patients (61 patients), the progression of enhancement or the occurrence of new vascular enhancement was rarely observed on follow-up HR-MRI (6 and 1 patients, respectively). CONCLUSIONS: Adult-onset MMD induces progressive shrinkage of large intracranial arteries, which cilostazol treatment may prevent. Further randomized clinical trials are warranted. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT02074111.

Surgical Strategy for Ethmoidal Dural Arteriovenous Fistula.

OBJECTIVE: Ethmoidal dural arteriovenous fistula (DAVF) is a rare type of intracranial DAVF. The aim of this study was to report our experience with a unilateral approach and discuss its effectiveness for ethmoidal DAVF treatment. METHODS: The study included 19 patients who underwent surgical treatment for ethmoidal DAVF between January 1999 and May 2021. RESULTS: Median age of patients was 59.7 years; 16 (84%) patients were male. Three patients had a ruptured ethmoidal DAVF. Preoperative digital subtraction angiography showed that all ethmoidal DAVFs were supplied by the bilateral external carotid artery branches. In 18 (95%) patients, cortical draining veins were located on the unilateral side. Bilateral lesions were identified in only 1 (5%) patient. The frontobasal approach was performed in 5 patients (26%), the pterional approach was performed in 5 (26%) patients, and the lateral supraorbital approach was performed in 9 (47%) patients; median procedural times were 198 minutes, 172 minutes, and 111 minutes, respectively. Cortical draining vein was successfully disconnected in all 19 patients with 20 ethmoidal DAVFs. Complete obliteration of ethmoidal DAVF was confirmed in all patients, with no postoperative complications. No recurrence or related clinical events were reported in 13 (68%) patients over 12 months of clinical and radiological follow-up. CONCLUSIONS: We reconfirmed excellent outcomes of surgical treatment for ethmoidal DAVFs. Three different surgical strategies were attempted, and each had pros and cons. The lateral supraorbital approach is an efficient surgical option for unilateral ethmoidal DAVFs. Careful preoperative examination for the presence of bilateral drainage is essential.

Early clinical experience of using the Surpass Evolve flow diverter in the treatment of intracranial aneurysms.

PURPOSE: Here, we presented our early experience with flow diversion procedures using the Surpass Evolve flow diverter (SE, Stryker) and reported the feasibility and safety profile compared to those of a control group treated with other types of flow diverters. METHODS: We included 31 and 53 consecutive flow diversion procedures performed using the SE and other commercial flow diverters, respectively, to treat intracranial aneurysms at our institution. We used two commercial flow diversion systems in the comparison group: the pipeline embolization device and Surpass Streamline. RESULTS: In the SE group, technical failures occurred in three (9.7%) cases, due to either incomplete wall apposition (n = 1, 3.2%) or stent migration (n = 2, 6.5%). Major complications occurred in four (12.9%) cases: delayed rupture of the target aneurysm (n = 1, 3.2%), major ischemic stroke (n = 1, 3.2%), sudden death from an unidentified cause (n = 1, 3.2%), and parent artery occlusion with stent thrombosis (n = 1, 3.2%). Balloon angioplasty was performed in eight (25.8%) cases. On post-procedure MRI, a DWI-positive lesion was detected in three (9.7%) cases. After multivariate adjustment, the SE group was independently associated with less procedural time of ≥ 90 min (adjusted OR, 0.09; 95% CI, 0.03-0.29; p < 0.001), balloon angioplasty (adjusted OR, 0.22; 95% CI, 0.07-0.75; p = 0.015), and DWI-positive lesions (adjusted OR, 0.04; 95% CI, 0.01-0.19; p < 0.001). CONCLUSION: The SE is safe and easy to deploy.

Treatment Outcomes After Single-Device Flow Diversion for Large or Giant Aneurysms.

OBJECTIVE: We aimed to evaluate the efficacy and safety of single-device flow diversion in patients with aneurysms measuring ≥15 mm in diameter. METHODS: For this retrospective study, we extracted medical record data for patients with unruptured intracranial aneurysms, who underwent flow diversion, at the authors' institution between July 2014 and August 2019. The primary effectiveness outcome was defined as angiographic occlusion of the target aneurysm within 18 months without major (>50%) parent artery stenosis, major adverse events, or additional treatment. RESULTS: Thirty-five aneurysms in 35 patients were analyzed. Most aneurysms (n = 29, 82.9%) involved the anterior circulation. The median aneurysmal diameter was 18.3 mm, and the median neck size was 7.6 mm. Eleven (31.4%) aneurysms were considered giant (≥25 mm). The primary effectiveness outcome was achieved in 20 (57.1%) patients at a median of 10 months (interquartile range, 4.3-12.5) after flow diversion. Major adverse events occurred in 6 (17.1%) patients, including remote intraparenchymal hemorrhages (n = 2), a major ischemic stroke (n = 1), a delayed rupture of the target aneurysm (n = 1), and clinical deterioration caused by aggravated mass effect (n = 2). Multivariate logistic regression analysis found 2 independent predictors of the primary effectiveness outcome: the aneurysmal diameter (odds ratio, 0.71; 95% confidence interval, 0.54-0.86; P = 0.004) and the parent-vessel angle (odds ratio, 0.97; 95% confidence interval, 0.93-0.99; P = 0.017). CONCLUSIONS: Single-device flow diversion was shown to be ineffective for large or giant intracranial aneurysms with a high parent vessel angle.

How Cerebral Vessel Tortuosity Affects Development and Recurrence of Aneurysm: Outer Curvature versus Bifurcation Type.

BACKGROUND AND PURPOSE: Previous studies have assessed the relationship between cerebral vessel tortuosity and intracranial aneurysm (IA) based on two-dimensional brain image analysis. We evaluated the relationship between cerebral vessel tortuosity and IA according to the hemodynamic location using three-dimensional (3D) analysis and studied the effect of tortuosity on the recurrence of treated IA. METHODS: We collected clinical and imaging data from patients with IA and disease-free controls. IAs were categorized into outer curvature and bifurcation types. Computerized analysis of the images provided information on the length of the arterial segment and tortuosity of the cerebral arteries in 3D space. RESULTS: Data from 95 patients with IA and 95 controls were analyzed. Regarding parent vessel tortuosity index (TI; P<0.01), average TI (P<0.01), basilar artery (BA; P=0.02), left posterior cerebral artery (P=0.03), both vertebral arteries (VAs; P<0.01), and right internal carotid artery (P<0.01), there was a significant difference only in the outer curvature type compared with the control group. The outer curvature type was analyzed, and the occurrence of an IA was associated with increased TI of the parent vessel, average, BA, right middle cerebral artery, and both VAs in the logistic regression analysis. However, in all aneurysm cases, recanalization of the treated aneurysm was inversely associated with increased TI of the parent vessels. CONCLUSIONS: TIs of intracranial arteries are associated with the occurrence of IA, especially in the outer curvature type. IAs with a high TI in the parent vessel showed good outcomes with endovascular treatment.

Surgical outcome and prognostic factors in epilepsy patients with MR-negative focal cortical dysplasia.

OBJECTIVE: Focal cortical dysplasia (FCD) represents a heterogeneous group of disorders of the cortical formation and is one of the most common causes of epilepsy. Magnetic resonance imaging (MRI) is the modality of choice for detecting structural lesions, and the surgical prognosis in patients with MR lesions is favorable. However, the surgical prognosis of patients with MR-negative FCD is unknown. We aimed to evaluate the long-term surgical outcomes and prognostic factors in MR-negative FCD patients through comprehensive presurgical data. METHODS: We retrospectively reviewed data from 719 drug-resistant epilepsy patients who underwent resective surgery and selected cases in which surgical specimens were pathologically confirmed as FCD Type I or II. If the epileptogenic focus and surgical specimens were obtained from brain areas with a normal MRI appearance, they were classified as MR-negative FCD. Surgical outcomes were evaluated at 2 and 5 years, and clinical, neurophysiological, and neuroimaging data of MR-negative FCD were compared to those of MR-positive FCD. RESULTS: Finally, 47 MR-negative and 34 MR-positive FCD patients were enrolled in the study. The seizure-free rate after surgery (Engel classification I) at postoperative 2 year was 59.5% and 64.7% in the MR-negative and positive FCD groups, respectively (p = 0.81). This rate decreased to 57.5% and 44.4% in the MR-negative and positive FCD groups (p = 0.43) at postoperative 5 years. MR-negative FCD showed a higher proportion of FCD type I (87.2% vs. 50.0%, p = 0.001) than MR-positive FCD. Unilobar cerebral perfusion distribution (odds ratio, OR 5.41) and concordance of interictal epileptiform discharges (OR 5.10) were significantly associated with good surgical outcomes in MR-negative FCD. CONCLUSION: In this study, MR-negative and positive FCD patients had a comparable surgical prognosis, suggesting that comprehensive presurgical evaluations, including multimodal neuroimaging studies, are crucial for obtaining excellent surgical outcomes even in epilepsy patients with MR-negative FCD.

Gamma Knife Radiosurgery for Incidental, Symptomatic Unruptured, and Ruptured Brain Arteriovenous Malformations.

BACKGROUND: This study was performed to investigate clinical characteristics and outcome after gamma knife radiosurgery (GKS) in patients with incidental, symptomatic unruptured, or ruptured arteriovenous malformations (AVMs). METHODS: A total of 491 patients with brain AVMs treated with GKS from June 2002 to September 2017 were retrospectively reviewed. All patients were classified into the incidental (n = 105), symptomatic unruptured (n = 216), or ruptured AVM (n = 170) groups. RESULTS: The mean age at diagnosis of incidental, symptomatic unruptured, and ruptured AVMs was 40.3, 36.7, and 27.6 years, respectively. The mean nidus volume was 3.9, 5.7, and 2.4 cm3, respectively. Deep venous drainage was identified in 34, 54, and 76% patients, respectively. There were no significant differences in obliteration rates after GKS between the 3 groups (64.8, 61.1, and 65.9%, respectively) after a mean follow-up period of 60.5 months; however, patients with incidental AVM had a significantly lower post-GKS hemorrhage rate than patients with symptomatic unruptured or ruptured AVMs (annual hemorrhage rate of 1.07, 2.87, and 2.69%; p = 0.028 and p = 0.049, respectively). CONCLUSIONS: There is a significant difference in clinical and anatomical characteristics between incidental, symptomatic unruptured, and ruptured AVMs. The obliteration rate after GKS is not significantly different between the 3 groups. Meanwhile, an older age at diagnosis and lower hemorrhage rate after GKS in incidental AVMs suggest that they have a more indolent natural course with a lower life-long risk of hemorrhage.

Prospective Screening of Extracranial Systemic Arteriopathy in Young Adults with Moyamoya Disease.

Background RNF213 is a major susceptibility gene for moyamoya disease (MMD), characterized by chronic progressive steno-occlusion of the intracranial arteries. However, coincidental extracranial arteriopathy is sporadically described in a few cases and in children with MMD. Methods and Results This study prospectively enrolled 63 young adults (aged 20-49 years) without a known history of systemic vascular diseases who were confirmed to have definite (bilateral, n=54) or probable (unilateral, n=9) MMD, as per typical angiographic findings. Coronary and aorta computed tomography angiography was performed to characterize extracranial arteriopathy and investigate its correlation with clinical characteristics and MMD status, including the RNF213 p.Arg4810Lys variation (c.14429G>A, rs112735431). Altogether, 11 of 63 patients (17%) had significant (>50%) stenosis in the coronary (n=6), superior mesenteric (n=2), celiac (n=2), renal (n=1), and/or internal iliac artery (n=1). One patient showed both mesenteric and iliac artery stenosis. Patients with extracranial arteriopathy were more likely to have diabetes mellitus and posterior cerebral artery involvement. Moreover, a higher prevalence of extracranial arteriopathy was observed in the presence of the RNF213 p.Arg4810Lys variant (67% in homozygotes). After controlling for diabetes mellitus and posterior cerebral artery involvement, the p.Arg4810Lys variant was independently associated with extracranial arteriopathy (additive model; P=0.035; adjusted odds ratio, 4.57; 95% CI, 1.11-27.20). Conclusions Young adults with MMD may have concomitant extracranial arteriopathy in various locations. Patients with RNF213 variants, especially the p.Arg4810Lys homozygous variant, should be screened for systemic arteriopathy.

Correlations between interictal extratemporal spikes and clinical features, imaging characteristics, and surgical outcomes in patients with mesial temporal lobe epilepsy.

PURPOSE: The significance of interictal epileptiform discharges (IEDs) observed in the extratemporal lobe has not been fully evaluated in patients with mesial temporal lobe epilepsy (MTLE). This study aimed to evaluate the surgical outcomes, clinical features, and functional neuroimaging characteristics of patients in relation to the presence or absence of extratemporal IED in MTLE with hippocampal sclerosis (HS). METHODS: A total of 165 patients with HS-induced MTLE who had undergone anterior temporal lobectomy were enrolled and stratified into the extratemporal interictal epileptiform discharges (ETD) and the temporal lobe discharges (TD) groups. We analyzed the differentiating features of pre- and postsurgical evaluation data between the two groups. For outcome assessment, only patients with a follow-up of at least 2 years were enrolled, and the outcomes were classified based on Engel classification. RESULTS: The ETD group showed extensive glucose hypometabolism involving the temporal lobe and extratemporal regions (p < 0.001), and IEDs were observed bilaterally or contralateral to the ictal focus (p = 0.02). However, there was no difference in the surgical outcomes between the two groups. On multivariate analysis, statistically significant variables related to ETD occurrence including seizure onset age were not identified nevertheless. CONCLUSION: Our results indicate that ETD had a surgical outcome comparable to that of TD. Therefore, a surgical intervention need not be delayed even if extratemporal IED may be found in presurgical long-term scalp EEG monitoring.

Intracranial Aneurysms in Young Adult Patients: Surgical and Endovascular Treatment Outcomes.

BACKGROUND: Despite its relative rarity, the potential for loss of productive years makes aneurysmal subarachnoid hemorrhage (SAH) a considerably important entity in young adult patients (20-39 years of age). This study aimed to analyze outcomes of microsurgery (MS) and endovascular treatment (EVT) for saccular intracranial aneurysms (IAs) in young adult patients. METHODS: A total of 276 young adult patients with 315 IAs, treated with MS or EVT between January 2001 and December 2015, were studied. Major recurrence and treatment-related complications were the primary outcome measures. Functional outcomes in patients with SAH were also assessed. RESULTS: Major recurrence occurred in 21 cases (6.7%). Younger age (adjusted hazard ratio [aHR], 3.77; 95% confidence interval [CI], 1.45-9.83; P = 0.007), ruptured IA (aHR, 6.44; 95% CI, 2.09-19.89; P = 0.001), size (aHR, 1.84; 95% CI, 1.06-3.18; P = 0.030), and EVT (aHR, 7.21; 95% CI, 2.44-21.35; P < 0.001) were independently related to major recurrence. Treatment-related complications occurred in 5 cases (1.6%) and did not differ between the MS and EVT groups (P > 0.999). Unfavorable outcomes (modified Rankin scale score ≥2) were identified in 30 patients (19.6%) with SAH, and only Hunt and Hess grade was independently associated with unfavorable functional outcome. CONCLUSIONS: Both MS and EVT are safe for treating IAs in young adult patients. MS showed better durability of treatment and may be preferred over EVT in young patients in view of their longer life expectancy compared with older patients.

Moyamoya Disease and Spectrums of RNF213 Vasculopathy.

Moyamoya disease (MMD) is a rare cerebrovascular disease characterized by progressive stenosis of large intracranial arteries and a hazy network of basal collaterals called moyamoya vessels. A polymorphism (R4810K) in the Ring Finger Protein 213 (RNF213) gene, at chromosome 17q25.3, is the strongest genetic susceptibility factor for MMD in East Asian populations. MMD was regarded prevalent in childhood and in East Asian populations. However, the so-called MMD could represent only the tip of the iceberg. MMD is increasingly reported in adult patients and in Western populations. Moreover, the RNF213 variant was recently reported to be associated with non-MMD disorders, such as intracranial atherosclerosis and systemic vasculopathy (e.g., peripheral pulmonary artery stenosis and renal artery stenosis). In this review, we summarize the spectrums of RNF213 vasculopathy in terms of clinical and genetic phenotypes. Continuous efforts are required for pathophysiology-based diagnoses and treatment, which will benefit from collaboration between clinicians and researchers, and between stroke and vascular physicians.

Gamma Knife Radiosurgery for ARUBA-Eligible Patients with Unruptured Brain Arteriovenous Malformations.

BACKGROUND: A randomized trial of unruptured brain arteriovenous malformations (ARUBA) reported superior outcomes in conservative management compared to interventional treatment. There were numerous limitations to the study. This study aimed to investigate the efficacy of gamma knife radiosurgery (GKS) for patients with brain arteriovenous malformations (AVMs) by comparing its outcomes to those of the ARUBA study. METHODS: We retrospectively reviewed ARUBA-eligible patients treated with GKS from June 2002 to September 2017 and compared against those in the ARUBA study. AVM obliteration and hemorrhage rates, and clinical outcomes following GKS were also evaluated. RESULTS: The ARUBA-eligible cohort comprised 264 patients. The Spetzler-Martin grade was Grade I to II in 52.7% and III to IV in 47.3% of the patients. The mean AVM nidus volume, marginal dose, and follow-up period were 4.8 cm³, 20.8 Gy, and 55.5 months, respectively. AVM obliteration was achieved in 62.1%. The annual hemorrhage rate after GKS was 3.4%. A stroke or death occurred in 14.0%. The overall stroke or death rate of the ARUBA-eligible cohort was significantly lower than that of the interventional arm of the ARUBA study (P < 0.001) and did not significantly differ from that of the medical arm in the ARUBA study (P = 0.601). CONCLUSION: GKS was shown to achieve a favorable outcome with low procedure-related morbidity in majority of the ARUBA-eligible patients. The outcome after GKS in our patients was not inferior to that of medical care alone in the ARUBA study. It is suggested that GKS is rather superior to medical care considering the short follow-up duration of the ARUBA study.

The Role of Anterior Thalamic Deep Brain Stimulation as an Alternative Therapy in Patients with Previously Failed Vagus Nerve Stimulation for Refractory Epilepsy.

Deep brain stimulation (DBS) has provided new treatment options for refractory epilepsy; however, treatment outcomes of DBS in refractory epilepsy patients previously treated with vagus nerve stimulation (VNS) have not been clarified. Herein, treatment outcomes of DBS of the anterior nucleus of the thalamus (ANT-DBS) in patients who had previously experienced VNS failure are reported. Seven patients who had previously experienced VNS failure underwent ANT-DBS device implantation. VNS was turned off before DBS device implantation. Monthly seizure counts starting from baseline to 12-18 months after DBS were analyzed. Five (71.3%) of the 7 patients experienced a >50% reduction of seizure counts after DBS; 1 responder reached a seizure-free status after DBS therapy. Of the 2 nonresponders, 1 subject showed improvement in seizure strength and duration, which lessened the impact of the seizures on the patient's quality of life. This is the first study in which favorable outcomes of ANT-DBS surgery were observed in individual patients with refractory epilepsy who had not responded to prior VNS. Further studies with a larger number of subjects and longer follow-up period are needed to confirm the feasibility of ANT-DBS in patients who have previously experienced VNS failure.

Clinical Usefulness of Intraoperative Motor-Evoked Potential Monitoring during Temporal Lobe Epilepsy Surgery.

BACKGROUND AND PURPOSE: We aimed to determine the effectiveness of intraoperative neurophysiological monitoring focused on the transcranial motor-evoked potential (MEP) in patients with medically refractory temporal lobe epilepsy (TLE). METHODS: We compared postoperative neurological deficits in patients who underwent TLE surgery with or without transcranial MEPs combined with somatosensory evoked potential (SSEP) monitoring between January 1995 and June 2018. Transcranial motor stimulation was performed using subdermal electrodes, and MEP responses were recorded in the four extremity muscles. A decrease of more than 50% in the MEP or the SSEP amplitudes compared with baseline was used as a warning criterion. RESULTS: In the TLE surgery group without MEP monitoring, postoperative permanent motor deficits newly developed in 7 of 613 patients. In contrast, no permanent motor deficit occurred in 279 patients who received transcranial MEP and SSEP monitoring. Ten patients who exhibited decreases of more than 50% in the MEP amplitude recovered completely, although two cases showed transient motor deficits that recovered within 3 months postoperatively. CONCLUSIONS: Intraoperative transcranial MEP monitoring during TLE surgery allowed the prompt detection and appropriate correction of injuries to the motor nervous system or ischemic stroke. Intraoperative transcranial MEP monitoring is a reliable modality for minimizing motor deficits in TLE surgery.

Clinical Role of Microembolic Signals in Adult Moyamoya Disease With Ischemic Stroke.

Background and Purpose- Hemodynamic compromise has been implicated in moyamoya disease (MMD) with transient ischemic attacks or ischemic stroke. However, increasing evidence supports the notion that artery-to-artery embolism may also contribute to ischemic events based on microembolic signal (MES) monitoring. Methods- A total of 48 patients aged between 20 and 60 years with newly diagnosed MMD were enrolled and angiographically classified according to the Suzuki staging system. For detection of MESs, transcranial Doppler was performed at the middle cerebral artery bilaterally for a 30-minute period. Mean flow velocities in the middle cerebral artery were also evaluated and categorized into low (<40 cm/s), normal (40-80 cm/s), and high (>80 cm/s). Clinical characteristics, cerebral angiography findings, recent ischemic events within 3 months, and antiplatelet medication were correlated with transcranial Doppler findings. Results- MESs were detected in 11 of the 48 patients (23%), with a frequency of 11 of 89 (12%) examined hemispheres. The mean number of MESs was 2 (range, 1-6). Six of the 11 hemispheres (55%) presented with ischemic strokes or transient ischemic attacks, and 2 (18%) presented with hemorrhagic strokes. The presence of MESs was associated with recent ischemic events ( P=0.024) and high mean flow velocities ( P=0.016), which was usually observed in Suzuki stage I and II (early-stage MMD). After controlling for age, sex, and antiplatelet medication, both recent ischemic events (odds ratio, 6.294; 95% CI, 1.345-29.457; P=0.019) and high mean flow velocities (odds ratio, 6.172; 95% CI, 1.235-31.25; P=0.027) were found to be independent predictors of MESs. Conclusions- MESs were observed in patients with high mean flow velocities, particularly early-stage MMD, and clinically associated with recent ischemic events. A randomized controlled study is necessary to determine the efficacy of antiplatelet agents in the treatment of MES-positive MMD.

Cav-1 (Caveolin-1) and Arterial Remodeling in Adult Moyamoya Disease.

Background and Purpose- Moyamoya disease (MMD) is a unique cerebrovascular occlusive disease characterized by progressive stenosis and negative remodeling of the distal internal carotid artery (ICA). We hypothesized that cav-1 (caveolin-1)-a protein that controls the regulation of endothelial vesicular trafficking and signal transduction-is associated with negative remodeling in MMD. Methods- We prospectively recruited 77 consecutive patients with MMD diagnosed via conventional angiography. Seventeen patients with intracranial atherosclerotic stroke and no RNF213 mutation served as controls. The outer distal ICA diameters were examined using high-resolution magnetic resonance imaging. We evaluated whether the degree of negative remodeling in the patients with MMD was associated with RNF213 polymorphism, cav-1 levels, or various clinical and vascular risk factors. We also investigated whether the derived factor was associated with negative remodeling at the cellular level using the tube formation and apoptosis assays. Results- The serum cav-1 level was lower in the patients with MMD than in the controls (0.47±0.29 versus 0.86±0.68 ng/mL; P=0.034). The mean ICA diameter was 2.48±0.98 mm for the 126 affected distal ICAs in patients with MMD and 3.84±0.42 mm for the asymptomatic ICAs in the controls ( P<0.001). After adjusting for confounders, cav-1 levels (coefficient, 1.018; P<0.001) were independently associated with the distal ICA diameter in patients with MMD. In vitro analysis showed that cav-1 downregulation suppressed angiogenesis in the endothelial cells and induced apoptosis in the smooth muscle cells. Conclusions- Our findings suggest that cav-1 may play a major role in negative arterial remodeling in MMD.

Prognostic factors determining poor postsurgical outcomes of mesial temporal lobe epilepsy.

OBJECTIVES: To investigate the long-term postoperative outcomes and predictive factors associated with poor surgical outcomes in mesial temporal lobe epilepsy (MTLE). MATERIALS AND METHODS: We enrolled patients with MTLE who underwent resective surgery at single university-affiliated hospital. Surgical outcomes were determined using a modified Engel classification at the 2nd and 5th years after surgery and the last time of follow-up. RESULTS: The mean duration of follow-up after surgery was 7.6 ± 3.7 years (range, 5.0-21.0 years). 334 of 400 patients (83.5%) were seizure-free at the 5th postoperative year. Significant predictive factors of a poor outcome at the 5th year were a history of generalized tonic clonic (GTC) seizures (odds ratio, OR; 2.318), bi-temporal interictal epileptiform discharge (IED) (OR; 3.107), bilateral hippocampal sclerosis (HS) (OR; 5.471), unilateral HS and combined extra-hippocampal lesion (OR; 5.029), and bi-temporal hypometabolism (BTH) (OR; 4.438). Bi-temporal IED (hazard ratio, HR; 2.186), BTH (HR; 2.043), bilateral HS (HR; 2.541) and unilateral HS and combined extra-hippocampal lesion (HR; 2.75) were independently associated with seizure recurrence. We performed a subgroup analysis of 208 patients with unilateral HS, and their independent predictors of a poor outcome at the 5th year were BTH (OR; 5.838) and tailored hippocampal resection (OR; 11.053). CONCLUSION: This study demonstrates that 16.5% of MTLE patients had poor long-term outcomes after surgery. Bilateral involvement in electrophysiological and imaging studies predicts poor surgical outcomes in MTLE patients.

Risk of Recurrent Chronic Subdural Hematoma Associated with Early Warfarin Resumption: A Matched Cohort Study.

OBJECTIVE: Studies on resuming anticoagulation after burr-hole drainage for chronic subdural hematoma (CSDH) are limited. To evaluate the safety for early warfarin resumption after burr-hole drainage, we conducted a retrospective matched cohort study. METHODS: Between January 2008 and April 2015, 36 patients with warfarin-related unilateral CSDH and 151 patients with ordinary unilateral CSDH were enrolled in this study. Patients taking warfarin were managed homogeneously according to the study protocol, and the usual dosage of warfarin was resumed within 2 or 3 days of burr-hole drainage to reach a target international normalized ratio (INR) of 2.1. The primary outcome, defined as recurrent CSDH requiring repeated burr-hole drainage within 3 months of the initial surgery, was compared between the two groups. RESULTS: The primary outcome was observed in 4 (11%) of the 36 patients taking warfarin and in 18 (12%) of the 151 ordinary patients. After propensity score matching, the primary outcome was observed in 3 of 33 patients (9%) in the matched warfarin cohort and 11 of 74 patients (15%) in the matched ordinary cohort. When the results were analyzed using the generalized estimating equation, no significant difference was observed in the rate of recurrent CSDH between the 2 groups (P = 0.411). In addition, we found that recurrent CSDH was not related to postoperative international normalized ratio levels (P = 0.332). CONCLUSIONS: There was no definitive association between postoperative early warfarin resumption and the recurrence rate of CSDH. Patients with warfarin-related CSDH and a strong indication for anticoagulation can be managed by resuming warfarin within 3 days of burr-hole drainage.

Modified Arachnoid Plasty Reduces Chronic Subdural Hematoma after Unruptured Aneurysm Clipping : Technical Note.

OBJECTIVE: Chronic subdural hematoma (CSDH) is a rare complication of unruptured intracranial aneurysm (UIA) clipping surgery. To prevent postoperative CSDH by reducing subdural fluid collection, we applied the modified arachnoid plasty (MAP) during the UIA clipping surgery to seal the dissected arachnoid plane. METHODS: This retrospective study included 286 patients enrolled from July 2012 to May 2015. We performed arachnoid plasty in all patients, with MAP used after June 17, 2014. Patients were divided into two groups (non-MAP vs. MAP), and by using uni- and multivariate analyses, baseline characteristics, and relationships with postoperative CSDH between the two groups were analyzed. The degree of preoperative brain atrophy was estimated using the bicaudate ratio (BCR) index. RESULTS: Ten patients (3.5%) among 286 patients had postoperative CSDH after clipping. Nine (3.1%) were in the non-MAP group, and one (0.9%) was in the MAP group. The higher BCR index showed statistical significance with occurrence of postoperative CSDH in both uni- (p=0.018) and multivariate (p=0.012, odds ratio [OR] 8.547, 95% confidence interval [CI] 1.616-45.455) analyses. MAP was associated with a lower risk of postoperative CSDH (p=0.022, OR 0.068, 95% CI 0.007-0.683). CONCLUSION: This study shows that the degree of preoperative brain atrophy is associated with an increased occurrence of CSDH after clipping and that MAP could help reduce the risk of postoperative CSDH after unruptured aneurysm clipping via a lateral supraorbital approach.