Clinical EEG in cognitively impaired patients with Parkinson's Disease.

Parkinson's Disease Dementia (PD-D) is one of the most important non-motor signs in advanced PD and is the most influencing factor predicting nursing home placement. PD-related Mild Cognitive Impairment (PD-MCI) is a potential prodromal stage of PD-D. The Grand Total EEG (GTE) score is a rating scale for clinical EEG (Electroencephalography) analyses which is useful in the evaluation of different types of dementia. The purpose of the present study was to investigate the relationship between a short version of the GTE score and severity of cognitive deficits in PD. Nineteen patients with PD underwent neuropsychological testing and resting state EEG. Significant correlations with deteriorating cognition (combined Mini Mental Status Examination/Clock Drawing Test) were found for the overall short GTE score (Spearman Rank correlation, ρ=-.6; p<.05) and for the subscore "Frequency of Rhythmic Background Activity" (ρ=-.6; p<.05), indicating that these EEG measures increase with deteriorating cognition.