Table 8.

Random effects meta-analyses results between PD and AD subjects.

Region	Number of studies	Subjects		SMD	[95% CI]	Overall effect		Heterogeneity
		PD	AD			Z	P	I 2 [%]	P
Global	2	20	29	−3.27	[−6.86, 0.32]	−1.785	0.074	85.6	0.008
Frontal lobe	3	26	39	−2.21	[−4.11, −0.31]	−2.274	0.023	83.9	0.002
Parietal lobe	2	20	29	−2.75	[−6.15, 0.65]	−1.585	0.113	86.7	0.006
Occipital lobe	2	20	29	−1.70	[−2.62, −0.78]	−3.625	0	26.0	0.245
Temporal lobe	2	20	29	−2.75	[−5.75, 0.24]	−1.804	0.071	83.8	0.013

PD, Parkinson's disease; AD, Alzheimer's disease; SMD, Standardized mean difference; CI, confidence interval. The bold values indicate the value of P < 0.05.