In the framework of Alzheimer–Epilepsy Project of the National Brain Research Program of Hungary (KTIA_NAP_13-1-2013-0001), we performed 48 h-long EEG monitoring in 5 AD patients suffering from epilepsy. We analyzed the distribution of occurrence of ictal and interictal epileptiform EEG activity during wakefulness, non-REM sleep and REM sleep.
We found significantly higher preponderance of epileptiform EEG discharges during non-REM sleep periods compared to wakefulness. The sleep pattern of all patients was severely disturbed.
Long-term EEG with sleep studies appear necessary for the correct diagnosis of epilepsy in AD. We assume that epileptiform activity in slow-wave sleep as well as the disruption of the physiologic sleep pattern may have an impact on the impaired memory functions in AD. Further investigations are required to enlighten this important association.
EEG monitoring of sleep is necessary for the accurate diagnosis of dementia-associated epilepsy.