Jiechuan Ren

Real-time effects of centrotemporal spikes on cognition in rolandic epilepsy: An EEG-fMRI study

Objective: To identify the real-time effects of interictal rolandic spikes (or centrotemporal spikes [CTS]) on language, behavior, and cognitive function in patients with rolandic epilepsy (RE). Methods: We studied 22 medication-naive patients with RE using EEG-fMRI with a 3T MRI scanner. We used simultaneous EEG to define the pre-CTS, CTS, and post-CTS periods. We analyzed the dynamic functional connectivity maps of the rolandic network during the 3 interictal CTS periods. Results: The analysis of dynamic changes revealed positive correlations between the bilateral rolandic areas and the left inferior frontal gyrus (IFG; Broca area), the left inferior parietal lobe and the supramarginal gyrus (areas responsible for receptive language function), and the right IFG and left caudate. Anti-correlations were found in the default mode network (bilateral superior frontal gyrus, left middle frontal gyrus, left middle temporal gyrus, and right precuneus). Conclusions: Interictal CTS directly disrupts the functional brain networks responsible for language, behavior, and cognition in children with typical RE. It is important to suppress discharges to reduce the risk of neuropsychological impairments in children with RE.

Functional brain connectome and sensorimotor networks in rolandic epilepsy

PURPOSE Rolandic epilepsy (RE) is a form of well-characterized childhood epilepsy whose focal electroencephalographic abnormalities affect the same well-delineated local brain regions. Little is known about how the focal electroencephalographic discharges interfere with the topological organization of whole-brain networks in RE patients. METHODS Seventy-three patients RE patients and 73 healthy children underwent rsfMRI. The whole-brain functional networks were constructed by thresholding the partial correlation matrices of 90 brain regions, and their topological properties were analyzed using graph theory-based approaches. We used network-based statistics to evaluate functional connectivity. The correlations between the network properties and the clinical and cognitive characteristics were calculated. RESULTS The global topologic organization of the functional brain network was disrupted in RE patients, as manifested by reduced clustering coefficient and local and global efficiency and increased characteristic path length. The RE patients exhibited less connectivity among the sensorimotor areas; this reduction in the mean functional connectivity in this network correlated to altered global small-world properties. The RE patients exhibited decreased nodal centralities, predominantly in the bilateral postcentral gyrus, in the frontal, parietal and temporal lobes around the rolandic fissure and in areas related to linguistics and attention control (p<0.05, FDR-corrected). The altered nodal centralities in the bilateral postcentral gyrus and the left posterior cingulate cortex were correlated with subscales in Child Behavior Checklist. CONCLUSIONS These results support the hypothesis that RE is associated with systemic brain disorganization and that the functional defect in rolandic areas contribute to symptomatology and electrophysiology in RE. Nodal abnormalities appear to imply the disturbances in linguistics and attention observed in RE patients.

Altered attention networks in benign childhood epilepsy with centrotemporal spikes (BECTS): A resting-state fMRI study.

It is noteworthy that some children with benign childhood epilepsy with centrotemporal spikes (BECTS) show attention problems despite their favorable seizure outcome. Resting-state functional magnetic resonance imaging (fMRI) is a method widely used to detect brain network alterations in neuropsychiatric diseases. We used resting-state functional magnetic resonance imaging (fMRI) to investigate specific brain networks related to attention deficit in children with BECTS. Resting-state fMRI was performed in patients with BECTS with ADHD (n=15) and those with BECTS without ADHD (n=15) and in healthy controls (n=15). Unbiased seed-based whole-brain functional connectivity analysis was used to study the connectivity pattern of three resting-state networks, including the ventral attention network (VAN) and the dorsal attention network (DAN) and the default mode network (DMN). Patients with BECTS with ADHD displayed decreased functional connectivity in the DAN compared with other two groups, while patients with BECTS without ADHD showed increased functional connectivity in the DAN. Moreover, we found increased functional connectivity in the VAN and in the DMN in patients with BECTS with or without ADHD when comparing with controls. These results showed that the newly-diagnosed children with BECTS displayed brain activity alterations in the ventral and dorsal attention networks. The difference in the extent of impairment in the dorsal attention network of patients with BECTS with ADHD and patients with BECTS without ADHD may lead to improved understanding of the underlying neuropathophysiology and treatment of BECTS with ADHD and BECTS without ADHD.

Evaluation of levetiracetam and valproic acid as low-dose monotherapies for children with typical benign childhood epilepsy with centrotemporal spikes (BECTS)

PURPOSE This study aimed to compare the monotherapeutic efficacies of levetiracetam (LEV) and valproic acid (VPA) in a cohort of newly diagnosed children with typical benign childhood epilepsy with centrotemporal spikes (BECTS). METHODS A total of 56 children with typical BECTS were retrospectively reviewed in the analyses. Thirty-three children received LEV and 23 received VPA as initial monotherapy, and the treatments lasted for at least 18 months. RESULTS The average dosage of LEV was 22.7 ± 4.7 mg/kg/day, and that of VPA was 18.7 ± 5.7 mg/kg/day. The seizure-freedom rates were not significantly different between the two groups at 6 (57.5% vs. 60.9%), 12 (81.8% vs. 73.9%) or 18 months (100% vs. 100%). However, a greater number of the children taking VPA achieved Electroencephalography (EEG) normalization compared to those taking LEV both at 12 (78.3% vs. 45.5%) and 18 months (95.7% vs. 72.7%; p<0.05). No children discontinued therapy due to adverse effects during the follow-up. Only one child (4.7%) in the VPA group exhibited mild weight gain (BMI increase of 2 at the end of follow-up) but did not withdraw from treatment. CONCLUSION Low-dosage VPA and LEV monotherapies are equally effective in controlling seizures, but VPA exhibited better efficacy than LEV in improving the electrophysiological abnormalities of children with BECTS. None of the patients discontinued therapy, which was likely due to the administration of low dosages.

Clinical and Electroencephalographic (EEG) Features Associated With Refractoriness in Benign Childhood Epilepsy With Centrotemporal Spikes

The aim of this study is to identify clinical or electroencephalographic (EEG) features associated with refractoriness to the initial antiepileptic drug in typical benign childhood epilepsy with centrotemporal spikes. A total of 87 children with typical benign childhood epilepsy with centrotemporal spikes were retrospectively reviewed in the analyses. The patients were subdivided into 2 groups: patients whose seizures were controlled with monotherapy and patients requiring 2 medications. Sixty-three children achieved seizure freedom with monotherapy, whereas 24 received 2 medications for seizure control. Diffusing foci at the follow-up EEG and delayed treatment (duration >1 year) are 2 main risk factors associated with more refractory cases (P < .001). Delayed diagnosis (37.1%) and nonadherence to treatment (57.2%) contributed to delayed treatment. Our findings suggested that diffusing foci on EEG and delayed treatment are associated with more frequent seizures and refractoriness in benign childhood epilepsy with centrotemporal spikes. Diagnostic delays and nonadherence hindered timely care, which may represent opportunities for improved intervention.

Patterns of postictal cerebral perfusion in idiopathic generalized epilepsy: a multi-delay multi-parametric arterial spin labelling perfusion MRI study

The cerebral haemodynamic status of idiopathic generalized epilepsy (IGE) is a very complicated process. Little attention has been paid to cerebral blood flow (CBF) alterations in IGE detected by arterial spin labelling (ASL) perfusion magnetic resonance imaging (MRI). However, the selection of an optimal delay time is difficult for single-delay ASL. Multi-delay multi-parametric ASL perfusion MRI overcomes the limitations of single-delay ASL. We applied multi-delay multi-parametric ASL perfusion MRI to investigate the patterns of postictal cerebral perfusion in IGE patients with absence seizures. A total of 21 IGE patients with absence seizures and 24 healthy control subjects were enrolled. IGE patients exhibited prolonged arterial transit time (ATT) in the left superior temporal gyrus. The mean CBF of IGE patients was significantly increased in the left middle temporal gyrus, left parahippocampal gyrus and left fusiform gyrus. Prolonged ATT in the left superior temporal gyrus was negatively correlated with the age at onset in IGE patients. This study demonstrated that cortical dysfunction in the temporal lobe and fusiform gyrus may be related to epileptic activity in IGE patients with absence seizures. This information can play an important role in elucidating the pathophysiological mechanism of IGE from a cerebral haemodynamic perspective.