Table 1.

Demographics and clinical data

	PD	HC
Subjects N. (male/female)	94 (67/27)	15 (4/11)*
Age at SPECT	60 (38 - 75)	63 (51 - 74)
Age at motor symptoms onset	57 (37 - 72)
Disease duration	3 (1 - 5)
UPDRS motor score (part-III) [range 0 - 108]	19 (8 - 56)
Hoehn and Yahr stage [range 1 - 5]	2 (1 - 2)
L-Dopa in mg/day	400 (0 - 850)
LEDDs in mg/day	250 (70 - 1200)

Data are reported as median and range (brackets). Age at SPECT, age at motor symptoms onset and disease duration are in years. All patients were evaluated with the Unified Parkinson Disease Rating Scale motor part (UPDRS part III) in drugs-off state (i.e. after overnight withdrawal of specific drugs for PD, no patients was taking long-acting dopaminergic drugs). LEDDs were calculated as follow: 100 mg levodopa = 1.5 mg pramipexole = 6 mg ropinirole. * p = 0.0005.