Clinical correlates of quantitative EEG in Parkinson’s disease: a systematic review

OBJECTIVE To assess the relevance of Quantitative electroencephalography (qEEG) measures as outcomes of disease severity and progression in PD.
METHODS Main databases were systematically searched (January 2018) for studies of sufficient methodological quality that examined correlations between clinical symptoms of idiopathic PD and cortical (surface) qEEG metrics.
RESULTS Thirty-six out of 605 identified studied were included. Results were classified into four domains: cognition (23 studies), motor function (13 studies), effect of treatment (7 studies), and other (10 studies). In cross-sectional studies, EEG slowing correlated with global cognitive impairment and with diffuse deterioration in other domains. In longitudinal studies, decreased dominant frequency and increased θ power, reflecting EEG slowing, were biomarkers of cognitive deterioration at an individual level. Results on motor dysfunction and treatment yielded contrasting findings. Studies on functional connectivity at an ...