Unprovoked seizures in multiple sclerosis and systemic lupus erythematosus: a population-based case-control study.

To study the risk of developing unprovoked seizures among patients with multiple sclerosis (MS) and systemic lupus erythematosus (SLE), we used 1885 new onset seizure cases, 15,080 controls and defined exposure as a hospital discharge diagnosis of MS or SLE. The odds ratio with 95% confidence interval was 3.7 (CI 1.2-11.0) for MS and 8.0 (2.2-30.0) for SLE, suggesting an increased risk of unprovoked seizures in patients with both these diagnoses.