Table 2.
Neuropsychological tests results over time in PD vs. controls and PD vs. PDD participants
| Cognitive domain | Neuropsychological test | PD vs. control participantsa | PD vs. PDD participantsb | ||||||||||
| Time | Group | Time×Group | Time | PDD | Time×PDD | ||||||||
| β | p | β | p | β | p | β | p | β | p | β | p | ||
| Global cognition | MoCA* | –0.1 | 0.312 | –1.3 | < 0.001 | 0.0 | 0.960 | 0.8 | < 0.001 | –2.6 | < 0.001 | –0.7 | < 0.001 |
| MMSE* | –0.2 | 0.040 | –0.3 | 0.043 | –0.2 | 0.048 | 0.4 | 0.006 | –0.6 | 0.006 | –0.9 | < 0.001 | |
| Executive function and Verbal fluency | Phonemic Fluency* | 0.2 | 0.185 | –0.6 | 0.274 | 0.5 | 0.017 | 1.6 | < 0.001 | –2.3 | 0.006 | –1.1 | 0.002 |
| Semantic Fluency* | –0.3 | 0.129 | –1.9 | 0.005 | 0.2 | 0.317 | 0.8 | 0.024 | –3.5 | < 0.001 | –1.3 | < 0.001 | |
| OTS no. solved on first choice † | 0.1 | 0.992 | –2.2 | 0.315 | 4.6 | 0.376 | –0.8 | 0.900 | –5.3 | 0.313 | 7.1 | 0.405 | |
| Memory | PRM number correct † | 0.1 | 0.468 | –0.9 | 0.007 | –0.1 | 0.670 | 0.3 | 0.138 | –1.6 | 0.001 | –0.7 | 0.004 |
| PRM % correct † | 0.4 | 0.497 | –3.6 | 0.009 | –0.3 | 0.656 | 1.4 | 0.153 | –6.5 | 0.002 | –2.8 | 0.004 | |
| SRM number correct † | –0.3 | 0.016 | –0.9 | < 0.001 | 0.0 | 0.853 | –0.2 | 0.309 | –1.8 | < 0.001 | –0.1 | 0.564 | |
| SRM % correct † | –1.8 | 0.014 | –4.4 | 0.001 | –0.1 | 0.884 | –1.1 | 0.298 | –8.7 | < 0.001 | –0.5 | 0.654 | |
| PAL stages complete † | 0.0 | 0.839 | –0.6 | < 0.001 | 0.1 | 0.098 | 0.1 | 0.461 | –0.5 | 0.006 | –0.1 | 0.350 | |
| PAL total errors † | 0.1 | 0.919 | 1.4 | 0.458 | 0.3 | 0.770 | –1.5 | 0.302 | 2.4 | 0.369 | 2.6 | 0.061 | |
| PAL total trials † | –0.1 | 0.616 | 0.9 | 0.079 | 0.6 | 0.063 | –0.3 | 0.636 | –0.1 | 0.855 | 1.9 | < 0.001 | |
| PAL mean trials to success † | 0.0 | 0.963 | 0.2 | 0.026 | 0.1 | 0.093 | –0.1 | 0.460 | 0.4 | 0.004 | 0.3 | < 0.001 | |
| Attention | SRT mean † | 7.6 | 0.284 | 25.1 | 0.027 | 10.9 | 0.189 | –17.8 | 0.171 | 35.1 | 0.046 | 17.8 | 0.145 |
| Digit vigilance accuracy † | 0.1 | 0.932 | –3.0 | 0.023 | –1.0 | 0.198 | 2.1 | 0.037 | –8.1 | < 0.001 | –4.2 | < 0.001 | |
| Digit vigilance mean † | 0.3 | 0.924 | 24.8 | < 0.001 | 5.3 | 0.083 | –5.8 | 0.219 | 39.9 | < 0.001 | –0.6 | 0.890 | |
| CRT accuracy † | 0.6 | 0.002 | 0.2 | 0.490 | –0.5 | 0.026 | 0.3 | 0.361 | –0.8 | 0.090 | –0.7 | 0.022 | |
| CRT Mean † | 10.5 | 0.087 | 22.8 | 0.023 | 18.4 | 0.011 | 8.1 | 0.441 | 60.6 | < 0.001 | 40.6 | < 0.001 | |
| PoA † | 19.7 | 0.137 | 72.9 | 0.001 | 35.7 | 0.022 | –8.4 | 0.721 | 134.1 | < 0.001 | 57.5 | 0.012 | |
| PoA CoV † | 1.5 | 0.048 | 2.4 | 0.064 | –0.2 | 0.796 | 0.9 | 0.446 | 3.0 | 0.102 | 4.0 | < 0.001 | |
| Continuity of attention † | 0.3 | 0.282 | –1.2 | 0.051 | –0.6 | 0.078 | 1.1 | 0.020 | –4.1 | < 0.001 | –2.3 | < 0.001 | |
| Cognitive reaction time † | 2.3 | 0.690 | –4.5 | 0.645 | 4.1 | 0.531 | 11.7 | 0.235 | 25.8 | 0.080 | 12.1 | 0.189 | |
| Spatial working memory | SWM original accuracy † | 0.3 | 0.737 | –2.9 | 0.089 | –0.7 | 0.506 | 0.0 | 0.989 | –6.1 | 0.015 | –1.8 | 0.249 |
| SWM new accuracy † | –0.5 | 0.676 | –3.4 | 0.037 | –2.2 | 0.084 | –3.9 | 0.046 | –2.8 | 0.241 | –4.6 | 0.018 | |
| SWM SI † | 0.0 | 0.939 | –0.1 | 0.036 | 0.0 | 0.261 | 0.0 | 0.319 | –0.1 | 0.051 | –0.1 | 0.051 | |
| SWM original speed † | 10.9 | 0.806 | 68.1 | 0.275 | 68.1 | 0.195 | –1.7 | 0.983 | 312.0 | < 0.001 | 254.5 | 0.002 | |
| SWM new speed † | 22.0 | 0.597 | 110.6 | 0.082 | 58.5 | 0.232 | 35.2 | 0.626 | 309.5 | 0.001 | 235.7 | 0.001 | |
| SWM mean speed † | 14.5 | 0.738 | 85.0 | 0.162 | 74.6 | 0.146 | 20.3 | 0.792 | 302.5 | < 0.001 | 264.4 | 0.001 | |
Significant results after Benjamini–Hochberg procedure are highlighted in bold p < 0.023. aCovariates included in the model: age, education, sex and GDS-15. bCovariates included in the model: age, MDS-UPDRS III, Sex, GDS-15, Education, Time x MDS-UPDRS III. *Time points included: baseline, 18, 36, 54 and 72 months; †Time points included: baseline, 18, 36 and 54 months. Full details of missing data is available in Supplementary Table 2. MoCA, Montreal Cognitive Assessment; MMSE, Mini-Mental State Examination; OTS, One Touch Stockings; PRM, paired recognition memory; SRM, spatial recognition memory; PAL, paired associated learning; CRT, choice reaction time; PoA, power of attention; CoV, coefficient of variance; SWM, spatial working memory; SI, Sensitivity indices; MDS-UPDRS III, Movement Disorder Society Unified Parkinson’s Disease Rating Scale; GDS-15, Geriatric Depression Scale.