Table 2.

Neuroimaging stepwise regression model listing all variables in the model that met the 0.05 significance level.

	Partial R²	Model R²	F value	Statistical Significance
Total group (n=133)
Age	0.06	0.06	8.75	0.004
Disease duration	0.06	0.12	8.78	0.004
H-Y≤2 (n=42)
Age	0.24	0.24	12.47	p=0.001
Striatal DTBZ	0.12	0.36	7.31	p=0.01
H-Y>2 (n=91)
Age	0.04	0.04	3.81	p=0.05

H-Y = Modified Hoehn and Yahr

DTBZ = [¹¹C] dihydrotetrabenazine