Table A2.

Summary of the linear regression model predicting UPDRS score by model; Block 2 was entered in a stepwise manner.

Block	Variable	B	SE	β	t	p-value	Cumulative R2
2A: LINEAR REGRESSION MODEL PREDICTING UPDRS BY TRACER UPTAKE IN THE CONTRALATERAL CAUDATE
	Constant	16.69	3.34		4.99	<0.001
1	Duration of PD (months)	1.143	0.502	0.355	2.274	0.032
	Absorption level in contralateral caudate	−2.1	0.92	−0.33	−2.27	0.03	0.37 (p = 0.003)
2	rs6356 (carriership of A allele)	−4.48	1.75	−0.39	−2.56	0.01	0.5 (p = 0.001)
2B: LINEAR REGRESSION MODEL PREDICTING UPDRS BY MEAN TRACER UPTAKE IN BOTH SIDES OF PUTAMEN
	Constant	14.605	3.159		4.623	0.000
1	Duration of PD (months)	1.096	0.533	0.340	2.054	0.051
	Absorption level in putamen (ipsi-and contralateral)	−2.087	1.235	−0.263	−1.690	0.104	0.32 (p = 0.008)
2	rs6356 (carriership of A allele)	−4.571	1.842	−0.406	−2.481	0.020	0.46 (p = 0.002)