Déjà vu phenomenon-related EEG pattern. Case report()

BACKGROUND: Déjà vu (DV, from French déjà vu — “already seen”) is an aberration of psychic activity associated with transitory erroneous perception of novel circumstances, objects, or people as already known. OBJECTIVE: This study aimed to record the EEG pattern of déjà vu. METHODS: The subjects participated in a survey concerning déjà vu characteristics and underwent ambulatory EEG monitoring (12–16 h). RESULTS: In patients with epilepsy, DV episodes began with polyspike activity in the right temporal lobe region and, in some cases, ended with slow-wave theta–delta activity over the right hemisphere. There were no epileptic discharges in healthy respondents during DV. CONCLUSION: Two types of déjà vu are suggested to exist: “pathological-epileptic” déjà vu, characteristic of patients with epilepsy and equivalent to an epileptic seizure, and “nonpathological-nonepileptic” déjà vu, which is characteristic of healthy people and psychological phenomenon.