Dementia and seizures occur in a significant proportion of patients with increasing prevalence in the elderly. This chapter reviews the epidemiology of dementia and the epidemiology of seizures in the elderly and then looks for the reported coincidence of dementia and seizures. The prevalence of epilepsy shows a similar trend; prevalence increases from approximately 55 years of age and is more than twice that of the general population by 85 years of age or more. Seizures can present in an unusual fashion, such as transient epileptic amnesia. Rarely, seizures can occur at the time of diagnosis in patients with probable Alzheimer's disease. Routine investigations should also include an electrocardiogram, complete routine blood work including electrolytes, liver enzymes, kidney function, and blood cell count. Current animal work is encouraging in the further investigation of the overlap between hyperexcitability, cognitive decline, and established dementia.