Table 1

Participant demographics

	Control (N=20)	PD-NC (N=38)	PD-MCI (N=41)
Age in years at PET scan [range]	71.9 (9.7) [54–91]	72.3 (6.4) [57–88]	74.2 (4.8) [66–86]	F_2,96=1.2, p=0.31
Sex M:F	12:8	27:11	30:42	χ²=0.95, p=0.6
Years education	13.9 (3.8)	13.3 (3.6)	10.9 (3.3)	F_2,96=6.8, p<0.002 b,c
Disease duration at PET (months) [range]	–	7.9 (4.9) [2–24]	9.0 (9.3) [1–62]	T₇₇=0.6, p=0.5
Baseline assessment to PET scan (months) [range]	43 (2.8) [39–49]	1.9 (1.2) [0.2–4.7]	2.1 (1.3) [0.3–5.9]	T₇₇=0.6, p=0.5
Baseline—repeat assessment (months) [range]	20.0 (1.2) [18–24]	18.5 (0.68) [17–20]	18.6 (0.67) [17–20]	T₇₇=0.4, p=0.7
LEDD baseline	–	144 (115)	191 (140)	T₇₇=1.6, p=0.1
LEDD 18 months	–	299 (154)**	410 (206)**	T₆₉=2.6, p=0.013
UPDRS III baseline	–	23.2 (9.0)	28.3 (12.6)	T₇₇=2.2, p=0.043
UPDRS III 18 months	–	33.5 (12.0)**	37.8 (10.7)**	T₆₉=1.6, p=0.1
MMSE baseline	29.5 (0.7)	29.0 (0.9)	27.9 (1.5)	F_2,96=15, p=0.001 b,c
MMSE 18 months	29.6 (1.0)	28.9 (1.1)	27.1 (1.8)**	F_2,88=23, p=0.001 b,c
MoCA baseline	27.7 (1.9)	26.3 (2.6)	22.4 (3.6)	F_2,89=27, p=0.001 b,c
MoCA 18 months	27.6 (2.4)	26.7 (2.6)	23.1 (3.6)	F_2,88=19, p=0.001 b,c

Comparisons are either three-group ANOVA, or PD-NC versus PD-MCI unpaired t-test, or (for sex) χ². Baseline MoCA scores only available on 72 PD participants. Tukey post hoc tests p<0.01, a=PD-NC versus controls, b=PD-MCI versus controls, c=PD-MCI versus PD-NC.
Longitudinal change paired tests: *p<0.05 within group; **p<0.01 within group.
ANOVA, analysis of variance; F, female; LEDD, levodopa equivalent daily dose; M, male; MMSE, Mini-Mental State Examination; MoCA, Montreal Cognitive Assessment; PD-MCI, Parkinson's disease-mild cognitive impairment; PD-NC, Parkinson's disease-normal cognitive function; PET, positron emission tomography; UPDRS III, motor subsection of Unified Parkinson's Disease Rating Scale.