Epileptic seizures in multiple sclerosis: clinical and EEG correlations.

Epileptic seizures occur more frequently in multiple sclerosis (MS) patients than in the general population. We evaluated clinical, electroencephalographic (EEG) and magnetic resonance imaging (MRI) findings, as well as EEG-MRI correlations and the response to antiepileptic drugs (AEDs) in 270 consecutive patients with definite MS referred to our Department from 1995 to 2002. Thirteen (4.8%) subjects experienced epileptic seizures. In four cases, seizures manifested within 1-2 years ("early-onset"), and in six cases within 8-23 years ("late-onset") of MS diagnosis. Seizures were usually partial with secondary generalization. Thus, acute symptomatic seizures occurred in three cases. Epilepsy usually appeared late in the course of disease, although a single episode or a cluster of seizures can represent the onset symptom or a relapse of MS. Prognosis of epilepsy during the course of MS is usually good but the choice of AEDs remains a matter of debate