TABLE 2.

Group differences between preataxic and ataxic SCA3 mutations carriers and healthy controls (HC)

Metric	Preataxic SCA3 < HC	Ataxic SCA3 < preataxic SCA3	Ataxic SCA3 < HC
Cervical spinal cord
Cervical spinal cord, level C3, CSAa	**	**	**
Cervical spinal cord, level C2, CSAa	**	**	**
Brain stem
Medulla oblongata	**	**	**
Pons	**	**	**
Midbrain		*	*
Cerebellum
Cerebellum white matter		*	*
Cerebellum I–IV			*
Cerebellum V			*
Cerebellum VI			*
Cerebellum crus I			*
Cerebellum crusII		*	**
Cerebellum VIIb			*
Cerebellum IX			*
Cerebellum X		*	*
Cerebellum vermisb			*
Cerebrum
Caudate			**
Pallidum	*	*	*
Thalamus			*
Compound volumes
Cerebellum, anterior lobec	*		*
Cerebellum, superior posterior lobed			*
Cerebellum, inferior posterior lobee			*
Cerebellum gray matterf			*
Basal gangliag			*
Ventricles	Preataxic SCA3 > HC	Ataxic SCA3 > preataxic SCA3	Ataxic SCA3 > HC
Third ventricle		*
Fourth ventricle			*

Significance levels are given after post hoc Benjamini-Hochberg correction for multiple comparisons.

^*P < 0.0001.

^**P < 0.000.

^aCSA, mean cross-sectional area.

^bEntire vermis corresponding to the hemispheric lobules VI–X.

^cCerebellar lobules I–V.

^dCerebellar lobules VI, crus I, crus II, and VIIB.

^eCerebellar lobules VIIIA, VIIIB, and IX.

^fCerebellar lobules I–X and vermis.

^gPalldium, caudate, and putamen.