Table 2.
Cognitive Performance: All PD Cohorts and Controls.
| Cognitive domains and tests | Original PD-RBD | Original PD-nRBD | p value | Replication PD-RBD | Replication PD-nRBD | p value | Combined PD-RBD (A) | Combined PD-nRBD (B) | Controls (C) | p value; post hoc |
|---|---|---|---|---|---|---|---|---|---|---|
| (n = 21) | (n = 16) | (n = 32) | (n = 24) | (n = 53) | (n = 40) | (n = 69) | ||||
| Attention | ||||||||||
| Digit Span, scaled score | 9.7 ± 2.3 | 11.8 ± 2.4 | .01 | 9.6 ± 2.3 | 11.0 ± 3.0 | ns | 9.6 ± 2.3 | 11.3 ± 2.7 | 11.4 ± 3.2 | .003; A < B**, A < Cw** |
| Trail Making Test part A, time, sec | 57.3 ± 25.2 | 42.8 ± 16.8 | nsª | 54.8 ± 24.0 | 46.1 ± 20.0 | nsª | 55.8 ± 24.3 | 44.8 ± 18.6 | 37.4 ± 14.6 | .001ª; A > Cm*** |
| Stroop Color-Word Test | ||||||||||
| III-II time, sec | 74.8 ± 38.2 | 45.8 ± 14.2 | .03ª | 82.8 ± 38.7 | 49.5 ± 19.4 | .003ª | 79.5 ± 38.2 | 48.0 ± 17.4 | 47.4 ± 38.7 | .000ª; A > Bm,w***, A > Cm*** |
| III-II errors | 3.4 ± 4.2 | 0.8 ± 2.3 | .04ª | 3.0 ± 5.1 | 1.1 ± 2.9 | nsª | 3.2 ± 4.7 | 1.0 ± 2.7 | 0.6 ± 2.1 | .007ª; A > B*, A > Cm** |
| Executive functions | ||||||||||
| Trail Making Test part B, time, sec | 157.6 ± 92.0 | 97.0 ± 59.3 | .01ª | 170.4 ± 89.2 | 99.3 ± 87.9 | .04ª | 165.3 ± 89.6 | 98.4 ± 76.8 | 95.9 ± 43.8 | .000ª; A > Bm,w***, A > Cm*** |
| Part B–part A, time, sec | 100.3 ± 79.0 | 54.2 ± 49.0 | .02ª | 115.4 ± 72.4 | 53.2 ± 77.9 | .001ª | 109.4 ± 74.7 | 53.6 ± 67.1 | 58.5 ± 37.8 | .000ª; A > Bm,w***, A > Cm** |
| Stroop Color-Word Test | ||||||||||
| IV-III time, sec | 31.2 ± 10.9 | 22.3 ± 16.7 | ns | 31.9 ± 33.7 | 22.1 ± 23.3 | ns | 31.8 ± 29.3 | 22.2 ± 21.7 | 14.2 ± 36.8 | nsª |
| IV-III, errors | 4.0 ± 4.3 | 2.9 ± 4.8 | nsª | 6.2 ± 5.9 | 2.1 ± 4.0 | .03ª | 5.7 ± 5.6 | 2.3 ± 4.2 | 1.9 ± 3.7 | .003ª; A > Bw*, A > Cw** |
| Verbal fluency | ||||||||||
| Semantic | 26.7 ± 6.8 | 35.3 ± 6.9 | .000 | 28.8 ± 7.8 | 36.9 ± 10.1 | ns | 27.9 ± 7.4 | 36.3 ± 8.9 | 36.5 ± 6.8 | .000; A < Bm***, A < Cm,w*** |
| Letter | 32.0 ± 12.4 | 38.3 ± 9.4 | ns | 30.9 ± 11.0 | 39.4 ± 10.7 | ns | 31.3 ± 11.5 | 38.9 ± 10.0 | 37.2 ± 11.1 | .008; A < B*, A < C* |
| Episodic learning and memory | ||||||||||
| Verbal | ||||||||||
| RAVLT | ||||||||||
| Sum of trials 1 to 5 | 38.0 ± 8.6 | 45.5 ± 5.9 | .04 | 37.3 ± 12.5 | 47.3 ± 12.8 | ns | 37.5 ± 11.1 | 46.6 ± 10.5 | 49.3 ± 8.6 | .000; A < Bm**, A < Cm*** |
| List B | 4.8 ± 1.5 | 5.1 ± 1.4 | ns | 3.8 ± 1.9 | 5.1 ± 2.0 | ns | 4.2 ± 1.8 | 5.1 ± 1.8 | 5.6 ± 1.9 | .002; A < Cw** |
| Immediate recall | 6.4 ± 3.0 | 9.1 ± 2.6 | .03 | 7.0 ± 3.5 | 10.3 ± 4.1 | .04 | 6.8 ± 3.3 | 9.8 ± 3.6 | 10.4 ± 2.7 | .000; A < Bm**, A < Cm,w*** |
| Delayed recall | 7.1 ± 3.1 | 9.8 ± 2.1 | ns | 7.4 ± 3.5 | 10.1 ± 4.0 | ns | 7.3 ± 3.3 | 10.0 ± 3.4 | 10.0 ± 3.1 | .008; A < B*, A < C** |
| Recognition | 12.8 ± 2.6 | 13.9 ± 1.2 | ns | 12.7 ± 2.3 | 14.0 ± 1.3 | ns | 12.7 ± 2.4 | 13.9 ± 1.3 | 14.1 ± 1.2 | .009; A < Cm** |
| Nonverbal | ||||||||||
| Rey-O Complex Figure Test | ||||||||||
| Immediate recall | 11.6 ± 6.0 | 14.3 ± 6.1 | nsª | 14.2 ± 6.9 | 17.4 ± 7.1 | nsª | 13.2 ± 6.6 | 16.1 ± 6.8 | 15.3 ± 6.1 | ns |
| Delayed recall | 11.4 ± 5.2 | 12.9 ± 6.4 | nsª | 12.8 ± 7.0 | 16.4 ± 7.9 | nsª | 12.2 ± 6.3 | 15.0 ± 7.4 | 15.5 ± 6.0 | ns |
| Visuospatial | ||||||||||
| Rey-O Complex Figure Test, copy | 26.5 ± 7.1 | 30.1 ± 3.4 | .04 | 28.2 ± 5.0 | 31.0 ± 4.0 | ns | 27.5 ± 5.9 | 30.6 ± 3.7 | 30.3 ± 4.0 | .02; A < B* |
| Block Design, scaled score | 8.1 ± 1.9 | 12.0 ± 2.4 | .000 | 9.5 ± 3.2 | 10.2 ± 3.8 | ns | 8.9 ± 2.8 | 10.9 ± 3.4 | 11.5 ± 3.2 | .000; A < B*, A < Cm*** |
| Bells test, omissions | 4.1 ± 2.8 | 3.2 ± 4.7 | nsª | 2.8 ± 2.9 | 2.7 ± 3.7 | nsª | 3.4 ± 2.9 | 2.9 ± 4.1 | 2.2 ± 2.8 | nsª |
| Language | ||||||||||
| Boston Naming Test | — | — | — | 28.7 ± 1.8 | 29.4 ± 0.8 | ns | 28.7 ± 1.8 | 29.4 ± 0.8 | — | ns |
| Vocabulary, scaled score | — | — | — | 10.2 ± 2.0 | 11.6 ± 2.4 | ns | 10.2 ± 2.0 | 11.6 ± 2.4 | — | ns |
| MMSE language score | 7.8 ± 0.5 | 7.9 ± 0.5 | ns | 7.7 ± 0.7 | 8.0 ± 0.2 | ns | 7.7 ± 0.6 | 7.9 ± 0.4 | 8.0 ± 0.1 | .01; A < C* |
Results are expressed as mean ± standard deviation. ªlog transformations.
Also statistically significant when comparing Menm and Womenw only in the combined cohorts.
MMSE = Mini-Mental State Examination; ns = not significant; PD = Parkinson’s disease; PD-RBD = PD with REM sleep behavior disorder; PD-nRBD = PD without RBD; RAVLT = Rey Auditory-Verbal Learning Test.
***p < .001; ** = p < .01; * = p < .05.