BackgroundThe number of patients suffering post-stroke seizure after ischemic stroke (PSSi) is quite considerable, especially because ischemic stroke is more prevalent than hemorrhage in the general population. This study aimed to determine the predicting factors for seizure recurrence in ischemic stroke survivors and develop a clinical scoring system for the prediction of risks for seizure recurrence after the first PSSi.MethodsWe reviewed 3792 ischemic stroke patients from the Ewha Stroke Registry. A total of 124 (3.3 %) patients who experienced PSSi were recruited (mean follow-up for 44.4 months). Medical records concerning the etiology, functional disability, seizure onset latency from stroke, type of seizure, electroencephalography (EEG), and neuroimaging findings were statistically analyzed to derive a seizure recurrence risk scoring system.ResultsSeizures recurred in 35.4 % (17/48) of early PSSi patients (≤1 week since stroke onset) and 48.7 % (37/76) of late PSSi (>1 week) patients. Atrial fibrillation, large sized, and cortical stroke lesion were more common in late onset PSSi compared to those in early onset PSSi (p < 0.05). Seizure recurrence tended to be more prevalent in early PSSi patients with male gender, atrial fibrillation or cortical stroke lesion, severe functional disability, and partial seizures. Seizure recurrence in late PSSi group was more common in patients of young age (≤65 years old), male gender, large lesion size, and partial seizure type. The validity of seizure recurrence risk score in the early PSSi group was better when evaluating based on gender, atrial fibrillation, cortical lesion, functional disability, and partial seizure type, with sensitivity of 70.6 % and specificity of 71.0 %.ConclusionsOur study characterized the high risk group for seizure recurrence in patients with the first PSSi. PSSi patients with high risk score of seizure recurrence had a greater chance of developing epilepsy later. Therefore, they should be considered for further treatment such as antiepileptic drug medication in clinical practice.

Here, we report the structural evidence of cerebral white matter abnormalities in Charcot-Marie-Tooth (CMT) patients and the relationship between these abnormalities and clinical disability. Brain diffusion tensor imaging (DTI) was performed in CMT patients with demyelinating (CMT1A/CMT1E), axonal (CMT2A/CMT2E), or intermediate (CMTX1/DI-CMT) peripheral neuropathy. Although all patients had normal brain magnetic resonance imaging, all genetic subgroups except CMT1A had abnormal DTI findings indicative of significant cerebral white matter abnormalities: decreased fractional anisotropy and axial diffusivity, and increased radial diffusivity. DTI abnormalities were correlated with clinical disability, suggesting that there is comorbidity of central nervous system damage with peripheral neuropathy in CMT patients. ANN NEUROL 2017;81:147-151.

SummaryObjective: Patients with temporal lobe epilepsy (TLE) show brain connectivity changes in association with cognitive impairment. Seizure frequency and lateralization are 2 important clinical factors that characterize epileptic seizures. In this study, we sought to examine an interactive effect of the 2 seizure factors on intratemporal effective connectivity based on resting-state functional magnetic resonance imaging (rsfMRI) in patients with TLE. Methods: For rsfMRI data acquired from 48 TLE patients and 45 healthy controls, we applied stochastic dynamical causal modeling to infer effective connectivity between 3 medial temporal lobe (MTL) regions, including the hippocampus (Hipp), parahippocampal gyrus (PHG), and amygdala (Amyg), ipsilateral to the seizure focus. We searched for the effect of the 2 seizure factors, seizure frequency (good vs poor seizure control) and lateralization (left vs right TLE), on connection strengths and their relationship with the level of verbal memory and language impairment. Results: Impairment of verbal memory and language function was mainly affected by seizure lateralization, consistent with preferential involvement of the left MTL in verbal mnemonic processing. For the fully connected model, which was selected as the effective connectivity structure that best explained the observed rsfMRI time series, alterations in connection strengths were primarily influenced by seizure frequency; there was an increase in the strength of the Hipp to PHG connection in TLE patients with poor seizure control, whereas the strength of the Amyg to PHG connection increased in those with good seizure control. Furthermore, the association between connection strength alterations and cognitive impairment was interactively affected by both seizure frequency and lateralization. Significance: These findings suggest an interactive effect as well as an individual effect of seizure frequency and lateralization on neuroimaging features and cognitive function. This potential interaction needs to be evaluated in the consideration of multiple seizure factors. K E Y W O R D Seffective connectivity, functional MRI, language, memory, seizure frequency, seizure lateralization, temporal lobe epilepsy

Background and PurposeBenign childhood epilepsy with centrotemporal spikes (BECTS) does not always have a benign cognitive outcome. We investigated the relationship between cognitive performance and altered functional connectivity (FC) in the resting-state brain networks of BECTS patients.MethodsWe studied 42 subjects, comprising 19 BECTS patients and 23 healthy controls. Cognitive performance was assessed using the Korean version of the Wechsler Intelligence Scale for Children-III, in addition to verbal and visuospatial memory tests and executive function tests. Resting-state functional magnetic resonance imaging was acquired in addition to high-resolution structural data. We selected Rolandic and language-related areas as regions of interest (ROIs) and analyzed the seed-based FC to voxels throughout the brain. We evaluated the correlations between the neuropsychological test scores and seed-based FC values using the same ROIs.ResultsThe verbal intelligence quotient (VIQ) and full-scale intelligence quotient (FSIQ) were lower in BECTS patients than in healthy controls (p<0.001). The prevalence of subjects with a higher performance IQ than VIQ was significantly higher in BECTS patients than in healthy controls (73.7% vs. 26.1%, respectively; p=0.002). Both the Rolandic and language-related ROIs exhibited more enhanced FC to voxels in the left inferior temporal gyrus in BECTS patients than in healthy controls. A particularly interestingly finding was that the enhanced FC was correlated with lower cognitive performance as measured by the VIQ and the FSIQ in both patients and control subjects.ConclusionsOur findings suggest that the FC alterations in resting-state brain networks related to the seizure onset zone and language processing areas could be related to adaptive plasticity for coping with cognitive dysfunction.