Table. Subject Demographics, β-Amyloid Status, and Tau Protein.
| Characteristic | Participant Subgroup | P Value | |||
|---|---|---|---|---|---|
| Participants With Parkinson Disease–Cognitively Normal | Participants With Parkinson Disease–Mildly Cognitively Impaired | β-Amyloid–Negative Control Participants |
β-Amyloid–Positive Control Participants | ||
| Total | 15 | 14 | 25 | 24 | NA |
| Age, mean (SD), y | 66.6 (6.6) | 66.5 (4.9) | 71.7 (6.7) | 75.9 (3.0) | < .001a |
| Female, No. (%) | 8 (53) | 4 (29) | 14 (56) | 16 (67) | NA |
| Education, mean (SD), y | 17.9 (1.9) | 16.1 (2.0) | 17.2 (1.9) | 15.8 (1.8) | .01b |
| Cognitive assessments, mean (SD)c | 28.3 (1.3) | 27.2 (2.3) | 29.0 (1.0) | 28.9 (1.1) | .14d |
| UPDRS Motor subscores, mean (SD) | 24.9 (12.7) | 28.6 (10.9) | NA | NA | .40e |
| AD Braak staging 0, 1/2, 3/4, 5/6 | 5,8,2,0 | 6,8,0,0 | 9,16,0,0 | 4,14,6,0 | NA |
| β-Amyloid-positivef | 5 | 1 | 0 | 24 | NA |
Abbreviations: AD, Alzheimer disease; NA, not applicable; UPDRS, Unified Parkinson’s Disease Rating Scale.
P value compares all patients with Parkinson disease with all controls.
P value compares β-amyloid–positive control participants with all patients with Parkinson disease and β-amyloid–negative control participants.
Cognitive assessments were via the Montreal Cognitive Assessment Scale for patients with Parkinson disease and via the Mini-Mental State Examination for control participants.
P value compares patients with Parkinson disease who were cognitively normal with patients with Parkinson disease who were mildly cognitively impaired.
P value compares β-amyloid–positive control participants with all patients with Parkinson disease plus β-amyloid–negative control participants.
Three normal control participants 60 years or younger did not receive positron emission tomography scans to determine β-amyloid status, but were included in β-amyloid–negative group.