TABLE 1.
Demographics and results of clinical assessments
| Characteristic | Controls, n = 25 | PD high visual performers, n = 54 | PD low visual performers, n = 22 | Statistic |
|---|---|---|---|---|
| Age (years) | 67.4 (8.2) | 63.7 (7.5) | 69.3 (7.6) |
F = 7.119 |
| Male (%) | 12 (48) | 26 (48.1) | 15 (68.2) |
χ 2 = 2.890 P = 0.089 |
| Years of education | 17.8 (2.2) | 16.9 (2.9) | 18.1 (2.5) |
F = 1.919 P = 0.152 |
| Total intracranial volume (cm3) | 1542.9 (121.3) | 1628.5 (189.1) | 1657.0 (146.8) |
F = 3.246 |
| Vision | ||||
| Contrast sensitivity (Pelli Robson) d | 1.8 (0.2) | 1.8 (0.2) | 1.7 (0.1) |
H = 17.377 |
| Acuity (LogMar) d | −0.1 (0.3) | −0.1 (0.2) | −0.1 (0.1) |
H = 3.232 P = 0.199 |
| Color vision (D15) | 1.3 (2.4) | 2.7 (8.9) | 3.0 (4.9) |
H = 1.934 P = 0.380 |
| General cognition | ||||
| MCI | — | 13 (24.1) | 13 (59.1) |
χ2 = 2.933 P = 0.087 |
| MOCA | 29.0 (1.1) | 28.3 (1.9) | 27.0 (2.7) |
H = 8.333 P = 0.016 c |
| MMSE | 29.2 (0.9) | 29.1 (1.7) | 28.8 (1.2) |
H = 1.534 P = 0.464 |
| Mood | ||||
| HADS anxiety | 3.5 (3.4) | 5.4 (3.7) | 6.5 (3.9) |
H = 8.201 |
| HADS depression | 1.2 (1.5) | 3.2 (2.8) | 5.7 (3.4) |
H = 28.898 |
| Disease‐specific measures | ||||
| Years from diagnosis | — | 3.8 (2.3) | 4.9 (2.8) |
t = −1.787 P = 0.078 |
| UPDRS total score | — | 42.7 (16.3) | 53.7 (28.0) |
t = −2.102 P = 0.039 |
| UPDRS motor score | — | 22.4 (10.2) | 25.8 (16.2) |
t = −1.094 P = 0.278 |
| Habitual hallucinations | — | 6 (11.1) | 6 (27.3) |
χ2 = 1.976 P = 0.160 |
| UM‐PDHQ (hallucination severity score) | — | 0.5 (1.8) | 1.1 (2.1) |
t = −1.358 P = 0.179 |
| LEDD | — | 401.4 (211.6) | 492.8 (225.5) |
t = −1.653 P = 0.102 |
| RBDSQ | — | 4.0 (2.3) | 4.5 (1.9) |
t = −0.839 P = 0.404 |
All data shown are mean (SD) except sex and MCI.
Statistical comparisons shown are across the 3 groups with subscript for post hoc results, except for diseasespecific measures (comparing PD low and high visual performers). In bold are characteristics that significantly differed between PD low visual performers and PD high visual performers.
MCI, mild cognitive impairment; HADS, Hospital Anxiety and Depression Scale; MMSE, Mini–Mental State Examination; MoCA, Montreal Cognitive Assessment; UPDRS, Unified Parkinson's Disease Rating Scale; UM‐PDHQ, University of Miami Hallucinations Questionnaire; LEDD, levodopa‐equivalent dose; RBDSQ, REM Sleep Behavior Disorder Scale.
Statistically significant difference between PD high visual performers and PD low visual performers.
Statistically significant difference between PD high visual performers and controls.
Statistically significant difference between PD low visual performers and controls.
Best binocular score used; LogMAR, lower score implies better performance; Pelli Robson, higher score implies better performance.