Table 2.

Correlations between midbrain nuclei volumes and Parkinson’s disease motor severity

	Substantia Nigra r (p)	Subthalamic Nucleus r (p)	Red Nucleus r (p)
Duration	–0.49 (0.004)	0.14 (0.435)	–0.07 (0.722)
Age	–0.31 (0.082)	0.20 (0.276)	0.10 (0.593)
MDS-UPDRS-III total	–0.42 (0.016)	0.29 (0.104)	0.25 (0.162)
Bradykinesia-Rigidity total	–0.47 (0.007)	0.17 (0.339)	0.16 (0.373)
Tremor total	0.11 (0.579)	0.21 (0.282)	0.30 (0.116)
PIGD	–0.31 (0.103)	0.32 (0.092)	0.22 (0.261)
MDS-UPDRS-III Less-Affected	–0.37 (0.038)	0.33 (0.068)	0.31 (0.082)
Bradykinesia-Rigidity Less-Affected	–0.41 (0.019)	0.29 (0.107)	0.24 (0.191)
Tremor Less-Affected	–0.09 (0.635)	0.28 (0.125)	0.35 (0.053)
MDS-UPDRS-III More-Affected	–0.22 (0.225)	0.16 (0.370)	0.24 (0.195)
Bradykinesia-Rigidity More-Affected	–0.35 (0.053)	0.04 (0.850)	0.17 (0.363)
Tremor More-Affected	0.06 (0.765)	0.14 (0.448)	0.16 (0.398)

r, Spearmans’s rho correlation coefficient; MDS-UPDRS-III, Movement disorders Society United Parkinson’s disease Rating Scale part 3 motor exam; PIGD, postural instability/gait difficulty.