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Objective To describe morphological characteristics of the brainstem nuclei in response to chronic vagus nerve stimulation (VNS) in patients with refractory epilepsy. Background VNS is a treatment option for individuals with medically refractory epilepsy. While treatment with VNS may achieve up to 50% seizure reduction and is protective against sudden unexpected death in epilepsy (SUDEP), its mechanism of action is not fully understood. Long-term structural and cellular changes in response to VNS have rarely been addressed in humans. Methods Four autopsy cases with history of chronic epilepsy treated with VNS (VNS+) and 4 age- and sex-matched chronic epilepsy-related death cases without VNS (VNS-) were included. Detailed clinical and postmortem data were obtained. Serial horizontal sections of the brainstem were prepared and stained with hematoxylin, eosin, and luxol fast blue (HE/LFB). Three regions of interest (ROIs) were delineated, including nucleus tractus solitarius (NTS), locus coeruleus (LC), and the rostral pontine group of raphe nuclei (rRN). Immunohistochemistry studies were performed using antibodies to GFAP, NeuN, HLA-DR, and IBA-1. Immunolabeling index was analyzed. Results Three of the 4 VNS+ patients and all 4 control (VNS-) patients died of SUDEP. There was no laterality difference in the NeuN, GFAP, HLA-DR and IBA-1 expression in LC and NTS of VNS+ patients. Similarly, there was no difference in the rRN, LC, and NTS between the VNS+ and VNS- groups. Conclusion This study represents the first histopathological study of the long-term effects of VNS therapy in the human brain. There was no difference observed in the neuronal cell number, degree of astrocytosis, and neuroinflammation in the main brainstem vagal afferent nuclei after prolonged VNS treatment in patients with refractory epilepsy.

Background A significant proportion of the people with intellectual disabilities (ID) has epilepsy and lives in institutions. These patients tend to have atypical presentations of epileptic seizures with an increased risk of misdiagnoses. They often have drug-resistant epilepsy (DRE) requiring polypharmacy with increased risk of morbidity. The aim of this study was to determine the usefulness of Epilepsy Monitoring Unit (EMU) in the diagnosis and management of these patients. Methods This is a retrospective observational study of people with epilepsy and ID living in institutions that were admitted to the EMU at London Health Sciences Center (LHSC), from January 2014 to December 2016. Results Out of 1121 patients admitted to the EMU at the LHSC, 1.96% (N = 22) fulfilled the inclusion criteria for this study. The mean age was 34.5 years (interquartile range [IQR]: 28.8–53); 50%(N = 11) were female. Fourteen (63.6%) had generalized epilepsy. Six (27.3%) had a history of status epilepticus. The mean number of antiseizure medications (ASMs) in those patients was three (IQR: 2–4). Eight (36.4%) patients had severely impaired or no language skills and seven (31.8%) required wheelchair. Eleven (50%) had a mood disorder and seven (31.8%) of them were taking antipsychotic medications. The mean duration of admission duration was 6.6 days (IQR: 3.5–8.5). There was a clinical-electrographic correlation between the behavioral events and epileptic seizures in nineteen (86.4%) of the patients. Conclusions Admission to the EMU provided an accurate characterization of transient events in people with ID and epilepsy with improvement in their medical management.