Quantitative EEG and Cognitive Decline in Parkinson’s Disease

Table 2

EEG and MEG spectral markers which significantly discriminated between cognitive states in PD.

Author(s)	Diagnostic groups of patients with PD ()	Mean age (years)	Evaluative tests: cognitive pathology (criteria)	Parameter(s) showed significant difference between the groups with PD	Effect size (95% CI)
Bosboom et al. 2006 [48]	PD-D (13); PD-wD (13)	74.4; 71.7	Dementia (DSM-IV)	GRP delta (0.5–4 Hz) and GRP theta (4–8 Hz)	PD-wD versus PD-D; 1.47 (0.60, 2.34)
				GRP alpha (8–13 Hz) and GRP beta (13–30 Hz)	PD-wD versus PD-D; −1.47 (−2.34, −0.60)
				GRP gamma (30–48 Hz)	PD-wD versus PD-D; −1.47 (−2.34, −0.60)
Caviness et al. 2007 [35]	PD-D (8); PD-MCI (16); PD-NC (42)	78.0; 80.4; 74.6	Dementia (DSM-IV); MCI (Petersen 2004 [55])	GRP delta (1.5–3.9 Hz)	PD-NC versus PD-MCI; 0.11 (−0.47, 0.68); PD-MCI versus PD-D; 1.27 (0.35, 2.19); PD-NC versus PD-D; 1.46 (0.67, 2.29)
				GRP theta (4–7.9 Hz)	PD-NC versus PD-MCI; 0.75 (0.16, 1.34); PD-MCI versus PD-D; 0.38 (−0.46, 1.24); PD-NC versus PD-D; 1.37 (0.57, 2.17)
				GRP alpha (8–12.9 Hz)	PD-MCI versus PD-D; −0.86 (−1.75, 0.01); PD-NC versus PD-D; −1.01 (−1.79, −0.22)
				GRP beta 1 (13–19.9 Hz)	PD-NC versus PD-MCI; −0.63 (−1.21, 0.04); PD-MCI versus PD-D; −0.70 (−1.57, 0.17); PD-NC versus PD-D; −1.16 (−1.95, −0.37)
				GRP beta 2 (20–30 Hz).	PD-NC versus PD-MCI; −0.57 (−1.15, 0.02); PD-MCI versus PD-D; −0.81 (−1.69, 0.07); PD-NC versus PD-D; −1.21 (−2.00, −0.41)
				Peak frequency at locations P3, P4, and Oz	PD-NC versus PD-MCI; −0.90 (−1.51, −0.31); PD-MCI versus PD-D; −0.99 (−1.88, −0.10); PD-NC versus PD-D; −1.88 (−2.54, −1.20)
Bonanni et al. 2008 [36]	PD-DnF (19); PD-DF (16)	70.0	PD-D (history of PD preceded dementia for at least 24 months); cognitive fluctuations (CAF, Walker et al. 2000 [56])	GRP theta (4.0–5.5 Hz)	PD-DnF versus PD-DF; 2.82 (1.88, 3.75)
				GRP prealpha (5.6–7.9 Hz)	PD-DnF versus PD-DF; 5.26 (3.86, 6.67)
				GRP alpha (8.0–12.0 Hz)	PD-DnF versus PD-DF; −8.40 (−10.47, −6.32)
				Mean frequency	PD-DnF versus PD-DF; −0.93 (−1.64, −0.24)
				DF in parietooccipital derivations	PD-DnF versus PD-DF; −1.18 (−1.90, −0.46)
				DFV in parietooccipital derivations	PD-DnF versus PD-DF; 1.19 (0.47, 1.91)
Fonseca et al. 2013 [42]	PD-D (12); PD-wD (31)	70.3; 68.1	Dementia (Dubois et al. 2007 [57])	Mean absolute power delta (0.8–3.9 Hz)	PD-wD versus PD-D; 0.85 (0.16, 1.54)
				Mean absolute power theta (4.29–7.8 Hz)	PD-wD versus PD-D; 1.23 (0.52, 1.94)
Bousleiman et al. 2014 [46]	PD-MCI (41); PD-NC (12)	67.2	MCI (Litvan et al. 2012 [58]).	GRP alpha 1 (8–10 Hz)	PD-NC versus PD-MCI; −0.82 (−0.131, −0.001)
Gu et al. 2016 [43]	PD-D (9); PD-MCI (17)	56.7; 62.1	Dementia (DSM-IV); MCI (Petersen 2004 [55])	Beta (13–30 Hz) peak frequency	PD-MCI versus PD-D; 1.10 (0.27, 1.92)
				GRP alpha (8–13 Hz)	PD-MCI versus PD-D; −1.10 (−1.92, −0.27)
				alpha/theta ratio: alpha (8–13 Hz) divided by theta (4–7 Hz)	PD-MCI versus PD-D; −1.10 (−1.92, −0.27)

Original data not available, effect size and confidence intervals estimated using value conversion.
The study is longitudinal; only assessment on admission is shown in this table.
Age for groups of the patients is not available; age of the combined sample is shown.
Mean age not available, mean age calculated from median and range (Hozo et al. 2005 [59]).
CAF: Clinical Assessment of Fluctuations; DF: dominant frequency; DFV: dominant frequency variability; DSM-IV: Diagnostic and Statistical Manual of Mental Disorders IV; GRP: global relative power; MCI: mild cognitive impairment; PD: Parkinson’s disease; PD-NC: Parkinson’s disease without cognitive impairment; PD-MCI: Parkinson’s disease with mild cognitive impairment; PD-D: Parkinson’s disease with dementia; PD-wD: Parkinson’s disease without dementia; PD-DnF: Parkinson’s disease with dementia without cognitive fluctuations; PD-DF: Parkinson’s disease with dementia with cognitive fluctuations.