Risk of epilepsy after a single seizure in multiple sclerosis

Area of Science:

• Neurology
• Epileptology
• Clinical Epidemiology

Background:

• Multiple sclerosis (MS) is associated with an increased risk of epilepsy.
• The risk of developing epilepsy after a first seizure in MS patients remains unclear.
• The 2014 International League Against Epilepsy (ILAE) definition of epilepsy considers a 10-year recurrence risk exceeding 60% after a single unprovoked seizure.

Purpose of the Study:

• To investigate the risk of epilepsy in patients diagnosed with multiple sclerosis (MS) following their first seizure.
• To compare epilepsy risk in MS patients versus a control group after a first seizure.

Main Methods:

• Cross-sectional study utilizing Swedish national health registers, including the MS register and patient register.
• Inclusion of 15,810 patients with MS and 43,635 controls.
• Analysis of 289 MS patients and 222 controls with a first seizure or status epilepticus (SE) diagnosis, excluding prior epilepsy or known symptomatic causes.
• Kaplan-Meier curves employed to estimate epilepsy risk.

Main Results:

• The 10-year risk of epilepsy was 51.4% in MS patients versus 41.3% in controls.
• Patients with relapsing-remitting MS had a 46.1% 10-year epilepsy risk, similar to controls.
• Patients with secondary progressive MS showed a 60.7% 10-year epilepsy risk.
• MS patients experiencing status epilepticus (SE) had a significantly elevated 10-year epilepsy risk of 85.9%.

Conclusions:

• Patients with relapsing-remitting MS do not appear to have a higher risk of epilepsy after a first seizure compared to controls.
• While secondary progressive MS may confer a higher risk, it does not definitively exceed the ILAE threshold.
• Status epilepticus (SE) in MS patients indicates a high risk for subsequent epilepsy, suggesting potential benefits from early diagnosis and treatment.