Abstracts

Rationale: Epilepsy surgery is a highly effective treatment for specific types of refractory epilepsy, and once seizure freedom is achieved many patients and clinicians have to ponder whether to taper or discontinue antiepileptic drugs (AEDs). However, there is no standard of practice or evidence guides, and practices vary widely. To identify the perceived practice among Canadian epileptologists regarding discontinuation of antiepileptic drugs (AEDs) following successful resective surgery for temporal and extratemporal surgery Methods: We performed a survey of pediatric and adult epileptologists in Canada, using a 77-item questionnaire to explore attitudes, timing, rate of withdrawal, and factors contributing to the decision to withdraw AEDs after successful epilepsy surgery. Surveys were mailed with a postage-paid return envelope. Two subsequent surveys were mailed to non-respondents at 1-month intervals. All procedures received institutional review board approval Results: Surveys were sent to 80 epileptologist in all the Canadian provinces. At the time of this report, completed surveys from 57 (71%) of potentially eligible respondents have been received, representing all epilepsy centers across Canada. The minimum seizure-free period after epilepsy surgery before considering discontinuation of AEDs, varied substantially among responders, ie., >6 months in 9%, 6-11 months in 23%, >1 year in 49%, >2 years in 11%, and >2 years in 6%. EEG was required prior to deciding to discontinue AEDs by 72% of participants, MRI was required by 49%, and serum AED levels by 46%. Forty-five percent of participants considered the opinion of the patients very important in their decision to reduce or stop AEDs. Focal pathology and anterior temporal resection increased the likelihood of AED discontinuation, and persistent auras decreased it. Other results will be presented.Conclusions: Little information is available to guide decisions to discontinue AEDs in postsurgical seizure-free patients. Canadian epileptologists indicated that and EEG, and often an MRI and AED levels are performed before stopping AEDs. Generally, a good candidate for stopping AEDs has focal pathology, is completely seizure free, has anterior temporal lobe resection, complete resection of seizure focus, and has no remaining epileptiform discharges in the EEG. The data pertain to self-reported practice styles, and actual practice may differ.