When is pharmacologic prophylaxis after a first unprovoked seizure typically started?

• A. Always started after a first unprovoked seizure
• B. Often not started unless high risk of recurrence based on EEG/MRI and clinical factors; some patients may be started if risk is high.
• C. Only if the patient has a confirmed genetic marker
• D. Never started after a first unprovoked seizure

Answer: (B)

After a first unprovoked seizure, starting preventive seizure medications isn’t automatic. The main idea is to weigh the chance of having another seizure against the risks and side effects of treatment. If EEG shows epileptiform activity, MRI reveals a structural lesion (like mesial temporal sclerosis, cortical dysplasia, tumor, or prior injury), or there are clinical factors that raise the likelihood of recurrence (focal onset, abnormal neurologic exam, younger age with focal features, etc.), the risk of another seizure is higher and starting prophylaxis may be appropriate to reduce that risk. If the EEG and MRI are normal and clinical factors don’t suggest a high recurrence risk, clinicians often defer antiseizure medications to avoid unnecessary side effects, choosing close follow-up instead. Genetic markers alone don’t dictate treatment, and it’s not standard to never treat after a first seizure; the decision is individualized based on recurrence risk and patient values.