Electromyographic Activity in the EEG in Alzheimer's Disease: Noise or Signal?

Table 3

Correlations between EEG and EMG activity on the one hand and cognitive and neuropsychiatric scores on the other hand.

	CAMCOG	GDS^a	NPI mood/apathy	NPI hyperactivity	NPI psychosis^a
Eyes closed
EEG theta relative power	−0.54**	0.32	−0.45	−0.08	−0.14
Frontal EMG	−0.25	0.52**	0.43	0.30	−0.11
Temporal EMG	−0.12	0.39*	−0.01	−0.32	−0.24
Eyes open
EEG alpha reactivity	0.53**	−0.04	0.43	0.17	−0.02
Frontal EMG^a	−0.43**	0.33	0.13	0.20	−0.01
Temporal EMG^a	−0.05	0.35*	0.42	0.07	−0.24
Memory activation
EEG alpha reactivity	0.43**	−0.28	0.11	0.23	−0.37
Frontal EMG^a	−0.24	0.28	−0.21	0.07	−0.07
Temporal EMG^a	−0.30	0.28	−0.06	−0.11	−0.36

Values in the table are Pearson’s correlation coefficients. In ^aSpearman’s correlation coefficients are displayed, as values were not normally distributed. *P  ≤  .05 and **P  ≤  .01. Significant correlations are printed in bold. CAMCOG: Cambridge Cognitive Examination; GDS: Geriatric Depression Scale (N: 13 controls, 12 MCI and 9 AD); NPI: Neuropsychiatric Inventory (N: 5 MCI and 5 AD).