EEG markers of early Alzheimer's disease in computer selected tonic REM sleep

Abstract

All night sleep/wake EEGs were examined for diagnostic sensitive to early Alzheimer's diesease (AD) using computer automated techniques. Thirty-nine AD patients and 43 normal controls underwent 9 h of EEG recording in the sleep laboratory. All-night EEGs were screened for ideal, low artifact tonic REM sleep using autoregressive and power spectral techniques. The frequency spectral during tonic REM sleep revealed a significant shift towards slower wave formeds in AD vs. control subjects. Beta (> 12 Hz0 was reduced adn theta and delta (2–8 Hz) increased in AD compared to control groups. This frequency shift was demonstrated by several analytic techniques, including binned spectral energies and unique zones in the frequency spectra. Discriminant analyses using optimal binned EEG variables correctly classified 74% of AD and 98% of control subjects, and unique zone scores correctly classified 92% of AD and 95% of control subjects, indicating that these sleep EEG changes are apparently predictive of AD status.