SEIZURES IN PATIENTS WITH ALZHEIMER'S DISEASE

Abstract

Alzheimer disease (AD) is reported as a risk factor for epilepsy in several epidemiologic studies. Seizures are seen in 9-16 % of patients in AD, especially in the later stages of disease. Younger onset of AD and having severe dementia are reported as the independent risk factors for epilepsy. Two hundred and sixty-one patients diagnosed and followed up in dementia unit of a tertiary care university hospital in year 2013 as AD according to the National Institute on Aging and The Alzheimer's Association criteria, were included to this study. Patients with a history of previous epilepsy or seizures were excluded from the study population. Thirteen of 261 AD patients (5 %) had unprovoked new-onset seizures and diagnosed as epilepsy. Nine of epileptic patients were male and 4 were female. Stages of dementia were mild (n=3), moderate (n=7) and severe (n=3). The average ages were 80.0 (71-88 years) and 78.0 (73-88 years), respectively. The mean duration of AD were 7.6 years (3-10 years) in males and 6.5 years (5-10 years in females, with an overall mean duration of 7.3 years. Cerebral cortical and hippocampal atrophy were seen in cerebral magnetic resonance imaging (MRI), and electroencephalography (EEG) revealed epileptic discharges in temporal and fronto-central regions in 9 patients. There are increasing evidences that suggest the severity of AD is primarily associated with the risk of epilepsy in AD patients. There is also conflicting evidence whether longer duration of AD is associated with increased risk of seizures. In our study group, duration of AD was long and most of the patients (77 %) had moderate or severe AD, suggesting that the longer duration and the severity of AD are associated with the increased risk of seizures in AD.