The relationship between treatment with valproate, lamotrigine, and topiramate and the prognosis of the idiopathic generalised epilepsies.

OBJECTIVE: To examine a large population with idiopathic generalised epilepsy (IGE), and estimate the overall remission rates for the IGEs and subsyndromes in a clinic based sample. Remission rates on valproate, lamotrigine, topiramate, and combinations of these antiepileptic drugs were estimated and factors predicting outcome examined.

METHODS: All patients with IGE were identified from a computerised database and EEG records at large adult and paediatric epilepsy clinics. Data were recorded retrospectively on demographics and clinical information, seizure types and syndrome diagnosis, antiepileptic drug treatment details, and remission rates.

RESULTS: 54.3% of 962 patients had achieved a one year period of remission; this was most likely with valproate monotherapy (52.1%), with lower rates for lamotrigine and topiramate (16.7% and 34.6%, respectively). The combination of valproate and lamotrigine achieved a remission rate of 15.3%. The factor most predictive of a response to a particular antiepileptic drug regimen was the rank order in which it was given. Relapse rate was high (79.9%) after antiepileptic drug withdrawal in remission, particularly with juvenile myoclonic epilepsy (93.6%).

CONCLUSIONS: Valproate may be the most effective antiepileptic drug in the treatment of the IGEs. Combination therapy should be initiated if an adequate trial of valproate monotherapy is not effective, rather than switching to alternative monotherapy. Antiepileptic drug treatment needs to be lifelong in many adult patients with IGE.