Patients with early stage Alzheimer's disease (AD) had epilepsy-like activity in the brain that was too subtle to be picked up with standard EEG recording methods, but could be detected with intracranial electrodes. The findings, which were published in the May 1, 2017, online issue of Nature Medicine, suggest that epilepsy can occur early in AD, and may contribute to both memory problems and neuronal damage without being clinically apparent.