Table 3.

Comparative analysis of mean volumes of the deep GM structures, corrected by the skull volume, between the first and second MRIs and correlation coefficient between time and deep GM volume. There were no statistically significant differences in the volume of deep GM structures considered, nor a correlation between the time interval and volume of the anatomical structures considered.

Anatomical structures		First MRI (standard deviation)	Second MRI (standard deviation)	p value of the comparative analysis between the first and second MRIsa	Pearson correlation coefficient between time and volumeb (p value)
Thalamus	Left	0.4433 (0.0518)	0.4342 (0.0483)	0.0819	0.3694 (0.2372)
	Right	0.4314 (0.0467)	0.4234 (0.0502)	0.1139	0.3305 (0.2939)
Caudate	Left	0.2065 (0.0230)	0.2055 (0.0225)	0.5831	−0.2426 (0.4474)
	Right	0.2234 (0.0254)	0.2243 (0.0185)	0.7537	−0.0933 (0.7730)
Putamen	Left	0.3622 (0.0517)	0.3524 (0.0485)	0.0825	0.4738 (0.1197)
	Right	0.3520 (0.0448)	0.3458 (0.0442)	0.0563	0.3855 (0.2158)
Globus pallidum	Left	0.1045 (0.0136)	0.0986 (0.0109)	0.0738	0.3768 (0.2272)
	Right	0.0995 (0.0132)	0.0952 (0.0078)	0.1217	0.5655 (0.0553)
Accumbens	Left	0.0395 (0.0087)	0.0416 (0.0090)	0.2067	0.5267 (0.0784)
	Right	0.0376 (0.0075)	0.0374 (0.0096)	0.9295	0.3417 (0.2769)
Hippocampus	Left	0.2421 (0.0359)	0.2483 (0.0355)	0.2528	0.3367 (0.2845)
	Right	0.2457 (0.0333)	0.2496 (0.0355)	0.3154	0.1890 (0.5561)
Amygdala	Left	0.0929 (0.0148)	0.0967 (0.0124)	0.2967	−0.0091 (0.9776)
	Right	0.1027 (0.0150)	0.1066 (0.0139)	0.2144	0.2269 (0.4780)

Statistical tests used: ^aStudent's t-test for paired samples; ^bPearson correlation test.

GM: gray matter; MRI: magnetic resonance imaging.