Seizures in the elderly: Etiology and prognosis

Purpose: To determine the etiology, early mortality, predictors of prognosi s and diagnostic yields of EEG and CT scans of the head in new-onset seizur es in elderly patients. Methods: EEG records for the north-central region o f Saskatchewan, between 01/94 and 12/95 were reviewed to identify all adult s aged 60 years or older with new-onset seizures. Information on demographi cs, seizure type, etiology, EEG and neuroimaging studies, anti-epileptic tr eatment and course of epilepsy was obtained by review of medical records an d interview with the patient and/or family member. Results: Of 88 eligible subjects, 61 (69%) were contacted for follow-up, 19 (22%) were deceased (12 of whom who had a serious underlying etiology to their seizures, which was obvious at the time of initial presentation and led shortly to their demis e), 4 (5%) were lost to follow-up and 3 (5%) refused participation. Excludi ng those refusing participation, 74/84 (88%) patients presented with partia l or secondarily generalized seizures. Seizures were cryptogenic in 38/84 ( 45%), and due to stroke in 19/84 (23%). EEGs were abnormal in 61/84 (73%) c ases, with epileptiform discharge in 33/84 (39%). CT scans were abnormal in 57/84 (68%) cases with acute pathology in 29/84 (35%). Of the 61 patients participating in the follow-up interview, 54 (89%) were treated with antiep ileptic medication and seizure control was usually successful. Predictors f or ongoing seizures were more than 3 seizures at presentation, epileptiform activity on initial EEG and discontinuation of anti-epileptic medication f or lock of efficacy, Conclusion: Prognosis of new-onset seizures in elderly patients is favorable if seizures are not symptomatic of a life-threatenin g disorder.