Table 1.
Participant characteristics
| Variable | No Cognitive Impairment, n = 68 | PD‐MCI, n = 100 | PDD, n = 24 | P * |
|---|---|---|---|---|
| Age, y | ||||
| Mean (SD) | 66.1 (6.3) | 70.8 (7.4) | 72.4 (8.4) | <0.0001 |
| Range | 52.0–80.2 | 41.9–92.7 | 55.8–96.4 | NCI < PD‐MCI, NCI < PDD |
| Education years | ||||
| Mean (SD) | 16.5 (2.1) | 16.3 (2.5) | 16.3 (2.5) | 0.935 |
| Range | 12–20 | 12–20 | 12–20 | |
| Gender, male; n (%) | 29 (42.7) | 76 (76.0) | 19 (79.2) | <0.001 |
| NCI > PD‐MCI > PDD | ||||
| Disease duration, y | ||||
| Mean (SD) | 9.9 (6.2) | 11.3 (7.2) | 11.3 (5.8) | 0.385 |
| Range | 2–27 | 1–40 | 2–25 | |
| LEDD, mg/d | ||||
| Mean (SD) | 533.0 (407.6) | 686.6 (554.2) | 520.1 (515.1) | 0.099 |
| Range | 0–2300 | 0–2376 | 0–2205 | |
| MDS‐UPDRS, part III | ||||
| Mean (SD) | 20.7 (12.9) | 27.1 (11.6) | 30.9 (12.7) | <0.001 |
| Range | 1–64 | 7–67 | 6–60 | NCI < PD‐MCI, NCI < PDD |
| GDS | ||||
| Mean (SD) | 5.3 (1.3) | 5.7 (1.3) | 6.0 (1.7) | 0.029 |
| Range | 2–8 | 1–9 | 3–10 | NCI < PDD |
| PDAQ‐P | ||||
| Mean (SD) | 53.0 (7.0) | 48.8 (8.8) | 37.3 (11.3) | <0.0001 |
| Range | 30–60 | 26–60 | 19–54 | NCI > PD‐MCI > PDD |
| PDAQ‐SP | ||||
| Mean (SD) | 52.8 (8.7) | 49.9 (7.7) | 36.1 (13.7) | <0.0001 |
| Range | 28–60 | 28–60 | 11–56 | NCI > PDD PD‐MCI > PDD |
| MoCA | ||||
| Mean (SD) | 27.9 (1.7) | 24.5 (2.9) | 19.8 (3.2) | <0.0001 |
| Range | 24–30 | 17–30 | 11–25 | NCI > PD‐MCI > PDD |
| HVLT‐R total immediate recall | ||||
| Mean (SD) | 27.9 (3.4) | 21.4 (4.2) | 15 (4.4) | <0.0001 |
| Range | 21–35 | 11–32 | 6–23 | NCI > PD‐MCI > PDD |
| HVLT‐R delayed recall | ||||
| Mean (SD) | 10.1 (2.0) | 6.9 (2.6) | 4.2 (2.9) | <0.0001 |
| Range | 0–12 | 0–11 | 0–9 | NCI > PD‐MCI > PDD |
| Digit symbol | ||||
| Mean (SD) | 50.9 (9.0) | 38.8 (9.6) | 26.3 (10.3) | <0.0001 |
| Range | 35–73 | 19–70 | 0–45 | NCI > PD‐MCI > PDD |
| Trailmaking part Aa | ||||
| Mean (SD) | 28.9 (9.6) | 39.4 (13.0) | 64.9 (28.4) | <0.0001 |
| Range | 15–58 | 15–78 | 33–150 | NCI > PD‐MCI > PDD |
| Trailmaking part Ba | ||||
| Mean (SD) | 66.0 (21.1) | 108.4 (47.8) | 203.7 (75.3) | <0.0001 |
| Range | 26–131 | 40–300 | 77–300 | NCI > PD‐MCI > PDD |
| Letter number sequencing | ||||
| Mean (SD) | 10.8 (2.0) | 9.2 (1.8) | 6.7 (2.1) | <0.0001 |
| Range | 8–16 | 3–13 | 4–11 | NCI > PD‐MCI > PDD |
| Semantic verbal fluency | ||||
| Mean (SD) | 23.9 (4.3) | 17.5 (5.5) | 11.1 (4.2) | <0.0001 |
| Range | 14–33 | 5–34 | 3–18 | NCI > PD‐MCI > PDD |
| Phonemic verbal fluency | ||||
| Mean (SD) | 48.3 (11.6) | 40.2 (12.0) | 29.5 (9.5) | <0.0001 |
| Range | 24–74 | 15–71 | 17–45 | NCI > PD‐MCI > PDD |
| Judgment of line orientation | ||||
| Mean (SD) | 13.3 (1.7) | 11.6 (2.4) | 10.6 (2.3) | <0.0001 |
| Range | 7–15 | 5–15 | 7–15 | NCI > PD‐MCI > PDD |
P values based on 1‐way analysis of variance overall F for continuous variables or chi‐square for categorical variables. Pairwise post hoc tests were performed using Scheffe's or chi‐square tests.
Higher scores represent worse performance. For all other cognitive variables, higher scores represent better performance.
PDD, Parkinson's disease dementia; PD‐MCI, Parkinson's disease mild cognitive impairment; SD, standard deviation; LEDD, levodopa equivalent daily dose; MDS‐UPDRS, Uniform Parkinson Disease Rating Scale–Movement Disorders Society revision; NCI, no cognitive impairment; PDAQ‐P, Parkinson's Daily Activities Questionnaire–15, participant; PDAQ‐SP, Parkinson's Daily Activities Questionnaire–15, study partner; GDS, Geriatric Depression Scale; MoCA, Montreal Cognitive Assessment; HVLT‐R, Hopkins Verbal Learning Test‐Revised.