Evaluating the prevalence and type of seizures, and ananlyzing the electroencephalogram(EEG) and magnetic resonance imaging(MRI) of multiple sclerosis(MS) patients of MS society of khorasan Razavi province,Iran,from 2009 to 2014

Objective: Although the prevalence of seizure is higher in multiple sclerosis (MS) patients compared to the general population, there is no study to assess the epidemiology of non-epileptic seizures in MS and differentiating this disorder from other kinds of seizures. The aim of our study is to epidemiologically assess non-epileptic seizures in patients of Khorasan MS society (KMS) in order to find a diagnostic pattern in EEG and MRI to be associated with this disorder. Methods & Materials: We searched in a sample of 812 patients from the total population of 4000 MS cases in KMS for non-epileptic seizure cases. All the found cases were followed for 1 year and their seizure or MS attacks were followed in this period. All the patients underwent magnetic resonance imaging (MRI) and electroencephalography (EEG). Data regarding the severity of the lesion in MRI and EEG were entered in SPSS software and descriptive and analytic statistics were extracted. Results: From a total sample of 812 patients, 13 cases (1.6%) of MS related non-epileptic seizure were reported from them, 10 patients (76.9%) accepted to participate in the study. All the cases experienced generalized seizures and the MS type in 9(90%) cases except one (10%) with primary progressive MS, was relapsing remitting MS. Totally, Background slowing was observed in 6 cases (60%) (4 mild cases (40%) and 2 sever cases (20%)). MRI findings showed cortical atrophy in 9 patients (90%) (one mild case (10%), 6 moderate cases (60%) and 2 sever cases(20%)), subcortical and juxtacortical lesions in all cases (5 mild cases(50%), 3 moderate cases(30%) and 2 sever cases(20%)) and other white matter lesions also in all cases (9 moderate cases(90%) and 1 sever case(10%)). There was no significant difference regarding the duration of the MS diagnosis in different severity of EEG and MRI pathologies (p value> 0.05). But there was significant difference regarding severity of cortical atrophy in severity of EEG backgrond slowing (Pvalue<0.036) and presence of EEG backgrond slowing in severity of subcortical and juxtacortical lesions (Pvalue<0.015) Conclusion: Although some pathologic findings have been found in EEG and MRI of these patients, still we cannot propose a pathognomonic feature for these Para clinic findings. Our study had a good sample size and the epidemiologic findings were useful; however conducting population-based studies is advisable due to the low number of MS cases with seizure.