This patient should be treated with a broad-spectrum antiepileptic drug (AED), such as topiramate. Given his history of recurrent unprovoked seizures, he clearly has an epilepsy syndrome, but the seizure features and results of ancillary testing do not definitively identify what kind of epilepsy syndrome. When it is unclear if a patient has focal or generalized epilepsy, treatment should be a broad-spectrum AED that can be used to treat both generalized and partial epilepsy syndromes. Topiramate is a broad-spectrum agent appropriate for both focal and generalized epilepsy; other appropriate drugs are lamotrigine, levetiracetam, valproic acid, and zonisamide. Patients starting topiramate should be counseled about the risk of developing kidney stones and the need to stay hydrated. Topiramate may offer additional advantages to patients with comorbid headaches. It also is associated with weight loss and thus may be of added benefit in patients who are overweight. However, the drug may have cognitive adverse effects, such as word-finding difficulty, in some patients. The risk of rash and Stevens-Johnson syndrome should be discussed with all patients starting an AED.

Carbamazepine, gabapentin, and phenytoin are all narrow-spectrum AEDs used to treat partial-onset epilepsies. They have the potential to exacerbate generalized epilepsy and may provoke absence status epilepticus. They should be used when the seizure characteristics or MRI and electroencephalogram clearly support the diagnosis of a partial onset seizure. Typical features suggestive of partial onset include specific auras (déjà vu or a rising epigastric sensation) and unilateral clonic shaking before onset.