Abstracts

Rationale: The prevalence of seizure disorders increases in older-aged patients and approaches 4% in individuals over 80 years of age. Patients with neurodegenerative diseases associated with a significant cognitive impairment are at increased risk of unprovoked seizure activity. The rationale for the present study is to characterize seizure-type(s), diagnosis of dementia, MRI and EEG findings, and response to antiepileptic drug (AED) medication in these individuals.Methods: A retrospective study was performed identifying patients in the Mayo Alzheimer Disease Patient Registry who were classified as having dementia and recurrent seizure activity. Sixty-three individuals were subsequently identified. Twenty-four of the 63 patients were excluded because of insufficient information concerning the seizure activity or response to AED therapy. The remaining 39 patients were included in the present series and subsequently analyzed.Results: The mean age was 76.9 years (range, 52 to 100 years). There were 21 females and 18 males. The neurodegenerative diseases associated with dementia included mild cognitive impairment (n=10), Alzheimer’s disease (n=9), vascular dementia (n=6), and Lewy body disease (n=5). Twenty-five patients (64%) had recurrent complex partial seizures and 15 patients (52%) had generalized tonic-clonic seizures. An MRI head was performed in 35 patients (90%). Fourteen patients (36%) had MRI-identified structural lesions that included remote stroke (n=12) or prior intracerebral hemorrhage (n=2). An EEG was obtained in 29 patients (74%). Fifteen patients (38%) had EEG-identified epileptiform discharges. The EEG in these individuals most commonly revealed unilateral or bitemporal spike or sharp wave discharges. Thirty-one patients (79%) became seizure-free or had a greater than 95% reduction of seizure frequency and less than three seizures per year with AED therapy. One patient (2.6%) had a 50% to 79% reduction of seizure frequency, and three individuals (7.7%) had less than a 50% reduction of seizure frequency with AED medication. Twenty-eight patients (72%) received one AED medication and 11 patients (28%) were on polypharmacy (two or more AED medications). Twelve patients (31%) had dose-related adverse effects. The most common medication related symptom was drowsiness in eight patients (21%). The remaining 27 patients (69%) had no drug-induced adverse effects.Conclusions: The present study indicated that most individuals with the comorbidity of recurrent seizures and dementia have complex partial seizures that may be adequately controlled on AED medication. Characteristically, the patients responded to the first AED therapy with minimal adverse effects. The long-term effect of seizure activity on the neurodegenerative disorder is unknown.