Abstracts

Epileptic auras provide important information about focal epilepsy and its location. Patients with focal epilepsy also report multiple aura types but limited data exists as to the significance of the occurence of multiple auras in the same patient. If multiple auras represent multiple seizure types or ictal onset zones, surgical treatment may not prove successful., The epilepsy monitoring unit database of the Cleveland Clinic was searched for patients with more than one aura type classified according to the Cleveland Clnic seizure classification system between the years 1989 and 2005. Clinical, EEG, and imaging data was analyzed to determine the location of the epileptogenic lesion, and explore possible mechanisms for the phenomenon of multiple auras., Thirty one patients were identified who experienced multiple auras during a given seizure. 90% of patients with more than one aura had seizures arising from the right/non-dominant hemisphere (N=31). 100% of patients with at least 3 auras had seizures arising from the right/non-dominant hemisphere (N=12). In two thirds of cases, the auras occurred as a sequence in the same seizure, and in one third the auras occurred simultaneously. 30/31 patients had seizures with preservation of awareness. EEG seizures remained restricted. Twenty of the patients had resective epilepsy surgery with a good outcome in 59%. Patients who did not have surgery were either not drug-resistant, lost to follow-up, or had tumor-related epilepsy. In one patient with seizures from both temporal lobes, right sided seizures were associated with multiple auras, and left sided seizures were associated with aphasic seizures with loss of awareness. Subdural EEG recordings in 6 patients showed either a [apos]jacksonian march[apos] of sequential auras, or in one case, several ictal onset zones resulting in separate isolated auras. Ictal SPECT images in 6 patients with right-sided seizures showed a lack of activation of the basal ganglia and brainstem., Most patients who report multiple aura types have localized epilepsy in the non-dominant hemisphere, and are good surgical candidates. The most common mechanism for multiple auras may be a spreading but restricted EEG seizure activating sequential symptomatogenic zones, but without the ictal activation of deeper structures or contralateral spread to cause loss of awareness and amnesia for the auras.,