Prognostic significance of quantitative electroencephalography in Alzheimer patients: preliminary observations

In 31 Alzheimer outpatients followed up for a mean time of 26.4 months the hypothesis that quantitative electroencephalography (qEEG) could predict the loss of activities of daily living (ADL), the onset of incontinence, and death was tested by the Weibull proportional hazard model of 'lifereg' procedure of the Statistical Analysis System package. A central-posterior temporal region was considered in either side (power-weighted, log transformed relative values). Right delta predicted both the loss of ADL and death, whereas right theta predicted the onset of incontinence. Left values gave borderline significant results toward all end-points, whereas power-weighted mean frequency always gave borderline results. The curves calculated for predicted times may be a valid support for the clinician in attempting prognostic judgments of disease evolution.