Abstracts

RATIONALE: Seizures begining later in life is a problem which is growing along with the aging population. More information is needed about seizure control, antiepileptic drug(AED) use and adverse effects of treatment in this age group.
METHODS: All patients in the Marshfield Epidemiological Study Area(MESA), 50 years of age or older who had their first unprovoked seizure between 7/1/96 and 6/30/98 were identified through the Marshfield Clinic diagnostic coding system. Incidence of seizures, etiology, and quality of life were previously evaluated(Epilepsia, Vol. 40 Suppl. 7, 1999). The current analysis included survival, degree of seizure control, initial and subsequent AED choice, and adverse effects.
RESULTS: Forty-eight patients were identified. Twenty-seven patients had recurrent seizures or a single seizure with an abnormal MRI, CT, or EEG. The other 21 patients had a single seizure and normal imaging and EEG. During the 12 month follow-up period, 6 of the 21 had one or more subsequent seizures. Twenty seven patients survived for the one year analysis period, 5 were lost to follow-up, and 16 died. Mean duration from initial seizure to death was 62 days(range 1 [ndash] 315), and the cause of death was possibly due to seizures in only one case. Of the 43 patients that were followed for one year or until death, 35 were seizure free, and 8 had continued seizures. Five of these 8 had less than 3 subsequent seizures. The other 3 had uncontrolled simple or complex partial seizures. One of these 3 presented with a large cerebral infarct and died 10 days later, one had severe degenerative dementia, and the other had a large left temporal meningioma. Initial AED choices were phenytoin(30), carbamazepine(9), valproate(5), and none(4). Thirteen patients(27%) experienced adverse effects resulting in discontinuation of the initial AED. Adverse effects occured with phenytoin(5), carbamazepine(5), and valproate(3), and included rash(5), dizziness(2), somnolence(1), cognitive impairment(1), blood dyscrasia(1), elevated liver enzymes(1), gastritis(1), and azotemia(1). Second AED choices were valproate(5), carbamazepine(1), phenobarbital(1), neurontin(1), and none(5).
CONCLUSIONS: Seizures were easily controlled in the vast majority of patients in this study. The few who had persistent uncontrolled seizures had severe underlying neurological disease. Older AED[scquote]s were the first and second choice in almost all patients, and adverse effects resulting in discontinuation were common. Newer AED[scquote]s which putatively have fewer adverse effects should be considered in this age group. Larger studies comparing newer and older AED[scquote]s are needed .
Support: Marsfield Medical Research Foundation
Disclosure: Grant - Research grants for data collection - no salary support.