Table 2.

FA and MD readings in normal-appearing white matter regions across the groups

NAWM regions	FA readings
	CISS/HS	CISNS/HNS	HS/HNS	CISS/CISNS
CC genu	0.84/0.84	0.86/0.85	0.84/0.85	0.84/0.86
CC body	0.68/0.68	0.71/0.65a	0.68/0.65	0.68/0.71
CC splenium	0.87/0.88	0.87/0.86	0.88/0.86	0.87/0.87
R corona radiata	0.46/0.49	0.49/0.53	0.49/0.53	0.46/0.49
L corona radiata	0.49/0.53	0.51/0.53	0.53/0.53	0.49/0.51
R SLF	0.56/0.59	0.54/0.56	0.59/0.56	0.56/0.54
L SLF	0.54/0.58	0.59/0.55b	0.58/0.55	0.54/0.59
R uncinate fasciculus	0.51/0.58	0.51/0.53	0.58/0.53	0.51/0.51
L uncinate fasciculus	0.45/0.49	0.52/0.52	0.49/0.52	0.45/0.52
R PLIC	0.69/0.62	0.68/0.65	0.62/0.65	0.69/0.68
L PLIC	0.68/0.62	0.73/0.65b	0.62/0.65	0.68/0.73
	MD readings
	CISS/HS	CISNS/HNS	HS/HNS	CISS/CISNS
CC genu	0.74/0.62	0.70/0.68	0.62/0.68	0.74/0.70
CC body	0.82/0.74	0.80/0.78	0.74/0.78	0.82/0.80
CC splenium	0.75/0.65a	0.76/0.68	0.65/0.68	0.75/0.76
R corona radiata	0.77/0.69b	0.74/0.71c	0.69/0.71	0.77/0.74
L corona radiata	0.77/0.68b	0.75/0.74	0.68/0.74c	0.77/0.75
R SLF	0.77/0.72d	0.77/0.75	0.72/0.75	0.77/0.77
L SLF	0.78/0.69a	0.75/0.74	0.69/0.74b	0.78/0.75a
R uncinate fasciculus	0.78/0.73	0.80/0.77	0.73/0.77	0.78/0.80
L uncinate fasciculus	0.80/0.74	0.77/0.75	0.74/0.75	0.80/0.77
R PLIC	0.74/0.69	0.73/0.73	0.69/0.73	0.74/0.73
L PLIC	0.76/0.69	0.71/0.73	0.69/0.73	0.76/0.71

Data represent mean FA and MD (×10⁻³ mm²) measurements in four matched groups.

FA, fractional anisotropy; MD, mean diffusivity; NAWM, normal-appearing white matter; CIS_S, smoker patients with clinically isolated syndrome; H_S, smoker healthy controls; CIS_NS, nonsmoker patients with clinically isolated syndrome; H_NS, nonsmoker healthy controls; CC, corpus callosum; R, right; L, left; SLF, superior longitudinal fasciculus; PLIC, posterior limb of the internal capsule.

^aP = 0.01;

^bP = 0.03;

^cP = 0.02;

^dP = 0.002.