Abstracts

Rationale: Based on previous studies, approximately 30% of patients with epilepsy have inadequate control of seizures with drug therapy. Some studies have identified that the response to the first antiepileptic (AED) drug with freedom of seizures is an important diagnostic clue to predict the evolution of the syndrome. We present a cohort of patients with newly-diagnosed epilepsy and assess response to first antiepileptic treatment, in order to assess the development of intractability. Methods: All patients seen in the new-onset seizure clinic at the London Health Sciences Center/University of Western Ontario-Epilepsy Programme were included in a prospective and systematic way since 2006. Demographics as well as clinical history were obtained. Epilepsy was classified as idiopathic, symptomatic, or cryptogenic. Response to treatment with antiepileptic medication was assessed. Patients were considered to be seizure-free if they had not had seizures of any type between visits. Results: 163 patients were included. The mean age was 37 years (range: 10-84). Information was available for 127 patients, of these 94 became seizure free and 34 continued to have seizures. When the two groups were compared, there were no differences in sex, history of febrile seizures, and family history of seizures (p> 0.05). The median age of onset was 36.8 years in those who became seizure free, and 31.2 years for those who persisted in having seizures. A higher proportion of patients with cryptogenic epilepsy (46.8%) were seen in those who became seizure free, while symptomatic epilepsy (45.5%) was most commonly seen in those who continued to have seizures. Otherwise, most of the group of patients who continued to have seizures had 20 or less seizures at presentation (n=24; 72.7%). Conclusions: Patients who began having seizures early in life and those with symptomatic epilepsy are likely not to become seizure free after treatment with the first AED.