Abstracts

Seizures can occur during sleep or wakefulness in medically refractory epilepsy patients undergoing video-EEG recording. Because recorded EEG seizures are essential for localizing seizure onset for epilepsy surgery, it is important to know whether there are differences in the localizing value of sleep seizures vs. wake seizures., Twenty-eight patients consecutively met the following criteria: excellent outcome after temporal lobectomy; age [gt]5 years; both wake and sleep seizures recorded and available for review; and no other seizure focus. Each seizure was reviewed without knowledge of patient identity, history, or video, to determine the following: extent of artifacts ([lt] vs. [gt] 25%); focal EEG discharge ([lt]2 electrodes); correct localization; and difference between EEG and clinical onset times., Fifty-eight sleep and 76 wake seizures were reviewed. Regression analysis shows that seizures during sleep are 2 1/2 times more likely to detect seizure focality than wake seizures, and 4 times more likely to correctly localize seizure onset. EEG seizure onset preceded clinical onset by a longer duration in sleep than in wake seizures (mean of 4.69 vs. 1.23 sec; p=0.002). Sleep seizures also show a strong trend for fewer artifacts., EEG seizures during sleep have more localizing value than wake seizures in temporal lobectomy candidates. The localizing information of sleep seizures could potentially influence the need for further procedures such as PET and SPECT, or the extent of intracranial EEG recording. Considerations may have to be made to favor the recording of seizures during sleep in temporal lobectomy candidates.[table1],