Does the cause of localisation-related epilepsy influence the response to antiepileptic drug treatment?

Purpose: We investigated the response to antiepileptic drug (AED) therapy i n patients with localisation-related epilepsy associated with different und erlying causes. Methods: Five hundred and fifty adolescent and adult patients who had parti al epilepsy treated with AEDs and who had undergone magnetic resonance imag ing of brain were followed up prospectively from 1984 at a single centre. M ore than 70% were newly diagnosed. None had had epilepsy surgery. Results: Three hundred and twelve (57%) patients had been seizure free at t heir last clinic visit for at least a year. Patients with mesial temporal s clerosis (MTS: n = 73, 42% seizure free) were less likely to be controlled (p < 0.01) than were those with arteriovenous malformation (AVM; n = 14. 78 %). cerebral infarction (n = 46, 67%), primary tumour (n = 35, 63%). cortic al gliosis (n = 81, 57%), cerebral atrophy (n = 49, 55%), and cortical dysp lasia (CD; n = 63, 54%). Among the seizure-free patients, those with MTS we re more likely to require more than one AED compared with those with other aetiologies (48 vs. 35%: p < 0.05). There was no difference in outcome betw een patients with symptomatic and cryptogenic epilepsy in = 361, 58% vs. n = 189, 56% seizure free, respectively). Patients with MTS. CD, and cryptoge nic epilepsy were more likely (p = 0.02) to have a family history of epilep sy than were the other groups. MTS patients also had a higher incidence of febrile convulsions (p < 0.001). Conclusions: The majority of patients with focal-onset epilepsy became seiz ure free on AED treatment. MTS-related seizures had the worst prognosis. Al though many patients with this pathology may benefit from epilepsy surgery, a considerable number will be controlled with AED therapy.