Epilepsy as a predictor of disease progression in multiple sclerosis.

BACKGROUND: Epilepsy development during the course of multiple sclerosis (MS) is considered to be the result of cortical pathology. However, no long-term data exist on whether epilepsy in MS also leads to increasing disability over time. OBJECTIVE: To examine if epilepsy leads to more rapid disease progression. METHODS: We analyzed the data of 31,052 patients on the German Multiple Sclerosis Register in a case-control study. RESULTS: Secondary progressive disease course (odds ratio (OR) = 2.23), age (OR = 1.12 per 10 years), and disability (OR = 1.29 per Expanded Disability Status Scale (EDSS) point) were associated with the 5-year prevalence of epilepsy. Patients who developed epilepsy during the course of the disease had a higher EDSS score at disease onset compared to matched control patients (EDSS 2.0 vs 1.5), progressed faster in each dimension, and consequently showed higher disability (EDSS 4.4 vs 3.4) and lower employment status (40% vs 65%) at final follow-up. After 15 years of MS, 64% of patients without compared to 54% of patients with epilepsy were not severely limited in walking distance. CONCLUSION: This work highlights the association of epilepsy on disability progression in MS, and the need for additional data to further clarify the underlying mechanisms.