Table 1.

Comparison of white matter tract characteristics by disease group

Disease group	Measure	CST	ICP	MCP	SCP
LOCA	FA	0.339	0.024*	0.147	0.931
	MD	0.825	0.685	0.152	0.779
	CS	0.028*	0.796	0.098	0.517
OPCA	FA	0.020*	0.167	0.000**	0.056
	MD	0.002**	0.829	0.000**	0.042*
	CS	0.000**	0.181	0.000**	0.752
SCA6	FA	0.081	0.777	0.128	0.013*
	MD	0.002**	0.878	0.297	0.036*
	CS	0.684	0.825	0.275	0.004**

All values represent significance levels determined by Student’s two-tailed t-tests. Areas of concordance between FA, MD, and cross-sectional area changes are indicated in bold text. Although the MD of the CST in SCA6 is statistically significant, the difference is in an unexpected direction, and there is no corresponding change or trend in the FA or CS

LOCA Late-onset cerebellar ataxia, OPCA olivopontocerebellar atrophy, SCA6 spinocerebellar ataxia type 6, FA fractional anisotropy, MD mean diffusivity, CS cross-sectional area, CST corticospinal tract, ICP inferior cerebellar peduncle, MCP middle cerebellar peduncle, SCP superior cerebellar peduncle

^*P < 0.05 trend,

^**P < 0.0065 critical value after false discovery rate control