Quantitative EEG and Cognitive Decline in Parkinson’s Disease

Table 4

Prediction of progression to dementia in Parkinson’s disease with spectral EEG markers.

Author(s)	Number of subjects, duration of observation after baseline EEG/MEG	Incidence of PD-D	Significant QEEG risk factor(s)
Klassen et al. 2011 [9]	PD-wD patients, 0.3 to 8.8 (mean 3.3) years	Incidence within 5 years by Kaplan-Meier method was 34%	Hazard ratios: background rhythm frequency < median (8.5) was 13.0; theta power > median (19.0) was 3.0
Gu et al. 2016 [43]	PD-MCI and 9 PD-D patients, 2 years	35% (6 PD-MCI patients progressed to PD-D patients)	Increase of the beta peak frequency and decrease of alpha relative power and alpha/theta ratio correlated with progression to PD-D; PPV of the combined marker was 62, and PLR was 4.4
Olde Dubbelink et al. 2014 [54]	PD-wD patients, 7 years	30% (19 patients)	Hazard ratios: beta power < median (27.96) was 5.21; peak frequency < median (8.39) was 3.97; theta power > median (22.85) was 2.82

PD-D: Parkinson’s disease with dementia; PD-MCI: Parkinson’s disease with mild cognitive impairment; PD-wD: Parkinson’s disease without dementia; PPV: positive predictive value; PLR: positive likelihood ratio.