Table 2:

Results of Kruskal-Wallis test showing group differences in DTI indices among periventricular white matter ROIs^{^a}

Group Comparisons	PIGD vs HC				PD vs HC				PIGD vs PD
Group Comparisons	FA	MD	AD	RD	FA	MD	AD	RD	FA	MD	AD	RD
WM fiber DTI indices
SLF		+	+								+
P value		0.04^{^b}	0.03^{^b}								0.04^{^b}
Longitudinal
ILF	−	+		+		+
P value	0.01^{^b}	0.001^{^b}		0.004^{^b}		0.009^{^b}
IFOF	−	+		+	−	+		+
P value	0.001^{^b}	0.003^{^b}		0.008^{^b}	0.01^{^b}	0.001^{^b}		0.04^{^b}
Thalamic
ATR	−
P value	0.04^{^b}
Callosal
BCC			+								+
P value			0.02^{^b}								0.003^{^b}
GCC										+	+
P value										0.01^{^b}	0.03

Note:—+ indicates higher group value; −, lower group value.
↵a Empty cells indicate no significant differences.
↵b Significant.