Clinical characteristics, course and prognosis of Multiple Sclerosis patients with epilepsy. A case control study: MS and epilepsy.

BACKGROUND AND PURPOSE: Although more common than in the general population, seizures are an atypical manifestation of multiple sclerosis (MS) and their pathophysiology is not well understood. This study aims to examine the prevalence, clinical characteristics, brain imaging findings and course of epilepsy, presenting in patients with MS. METHODS: Observational retrospective study of MS patients evaluated at a single MS reference center in Buenos Aires, Argentina, between 2011 and 2022, focusing on those who developed epilepsy (EMS). Clinical, demographic, and prognostic factors were evaluated and compared to a control group of non-epileptic MS patients (NEMS). To analyze specific epilepsy characteristics, a second control group of patients with non-lesional focal epilepsy (FNLE) was also included. RESULTS: Twenty-five patients (18 women), were diagnosed with epilepsy, corresponding to a prevalence of 1.95%. Comparison of brain imaging characteristics between EMS and NEMS patients showed brain atrophy (32% vs 6.1%, p<0.01), as well as cortical (26% vs 4%, p=0.03) and juxtacortical lesions (84% vs 55%, p=0.05), were more frequent in EMS patients. However, after multivariate analysis, cortical atrophy was the only variable linked to a significant increase in risk of epilepsy (OR 24, 95%CI=2.3-200, p<0.01). No significant differences in clinical characteristics, disease activity, disability levels, response to disease modified treatment (DMT) or lack of DMT efficacy were observed between MS patients with or without epilepsy. Most patients received anti-seizure medication (ASM), and seizure control was better in EMS than in FNLE patients (92% vs 58%, p=0.022) with no differences found in drug resistance. We did not find predictors of seizure recurrence in the population studied. CONCLUSION: We observed a lower prevalence of epilepsy in this group of MS patients, compared to other reported cohorts. Although epilepsy seems to have a benign course in MS patients, cortical atrophy appears to be an important contributor to the development of secondary epilepsy in MS patients. Further investigations will be necessary to identify risk factors or biomarkers predicting increased epilepsy risk in MS.

Predictive factors for the development of epilepsy after ischemic stroke.

OBJECTIVES: Ischemic stroke is one of the most common causes of epilepsy in adults. The incidence of post-stroke epilepsy (PSE) is approximately 7%. Risk factors are higher stroke severity, cortical localization, higher National Institute of Health Stroke Scale (NIHSS) upon admission and acute symptomatic seizures. We analyzed the predictive factors of PSE development in our population. MATERIALS AND METHODS: Retrospective observational cohort of adult patients (age ≥ 18 years) with ischemic stroke assessed between January 2012 and June 2020. Patients with personal history of epilepsy and potentially epileptogenic structural injury other than acute or chronic stroke were excluded. Demographic, clinical and imaging variables were evaluated in a multivariate analysis for independent risk factors associated with PSE. RESULTS: Medical records of 1586 stroke patients were reviewed, 691 met the inclusion criteria and had at least one year of follow-up. Of them, 428 (61.9%) were males. During follow-up, 6.2% had diagnosis of PSE (42/691) with a higher frequency of: previous ischemic stroke, higher NIHSS upon admission, treatment with rt-PA, higher Fazekas scale grade, cortical involvement, hemorrhagic transformation, acute symptomatic seizures, longer hospitalization and higher modified Rankin Scale (mRS) at discharge compared to the group without PSE. In a multivariate analysis, acute symptomatic seizures (OR=3.22, p: 0.033), cortical involvement (OR=0.274, p < 0.05), Fazekas scale score (OR=0.519, p < 0.05) and mRS at discharge (OR=1.33, p: 0.043) were independent risk factors. CONCLUSIONS: The variables related to higher risk of PSE were similar to those reported in the literature, highlighting the importance of neuroimaging findings, acute symptomatic seizures during hospitalization and neurological deficit at discharge. The data obtained will serve as the basis for construction of predictive models, allowing to individualize PSE probability in our population.