TABLE 1.
Demographics and clinical characteristics of participants
| Variables | HC (n = 29) | PD‐N (n = 17) | PD‐M (n = 24) | ANOVA p | Posthoc LSD | ||
|---|---|---|---|---|---|---|---|
| HC vs. PD‐N p | HC vs. PD‐M p | PD‐N vs. PD‐M p | |||||
| Age (years) | 52.8 ± 7.7 | 54.0 ± 8.2 | 54.3 ± 8.3 | .782 | .624 | .513 | .922 |
| Gender (male/female)a | 12/17 | 10/7 | 9/15 | .367 | .201 | .499 | .151 |
| Years of education | 10.4 ± 3.3 | 11.4 ± 2.5 | 9.6 ± 3.4 | .239 | .307 | .413 | .092 |
| Age at onset (years)b | NA | 50.9 ± 8.9 | 51.0 ± 9.0 | — | — | — | .995 |
| Disease duration (years)b | NA | 2.2 ± 1.6 | 3.3 ± 2.8 | — | — | — | .200 |
| Hoehn and Yahr stageb | NA | 1.8 ± 0.6 | 1.9 ± 0.6 | — | — | — | .669 |
| Unified PD rating scale IIIb | NA | 17.1 ± 9.7 | 24.3 ± 12.5 | — | — | — | .054 |
| Levodopa equivalent daily dose (mg/day)b | NA | 241 ± 305 | 291 ± 356 | — | — | — | .640 |
| Hamilton depression rating scale | NA | 6.1 ± 4.1 | 8.8 ± 5.1 | — | — | — | .081 |
| Mini‐mental state examination | 28.1 ± 1.5 | 28.8 ± 1.0 | 27.7 ± 2.0 | .122 | .170 | .387 | .088 |
| Montreal cognitive assessment | 22.2 ± 3.5 | 24.3 ± 2.4 | 19.3 ± 2.9 | <.001 | .063 | .004 | <.001 |
| Attention and working memory | |||||||
| Digit span backward | 4.6 ± 1.6 | 5.0 ± 1.3 | 4.3 ± 1.2 | .269 | .324 | .463 | .107 |
| Trail making test | 48.3 ± 21.1 | 49.2 ± 11.0 | 71.3 ± 45.6 | .021 | .925 | .011 | .028 |
| Executive function | |||||||
| Clock drawing test | 12.6 ± 1.5 | 12.5 ± 1.8 | 10.5 ± 3.3 | .004 | .917 | .003 | .008 |
| Verbal fluency test | 20.1 ± 5.2 | 19.7 ± 3.9 | 15.9 ± 4.6 | .005 | .799 | .003 | .012 |
| Language | |||||||
| Boston naming test | 25.1 ± 2.6 | 26.0 ± 1.5 | 22.7 ± 3.6 | .001 | .348 | .005 | .001 |
| Wechsler adult intelligence scale similarities | 16.2 ± 2.7 | 15.9 ± 3.4 | 12.3 ± 3.7 | <.001 | .745 | <.001 | .001 |
| Memory | |||||||
| Brief visuospatial memory test–revised | 20.6 ± 5.2 | 22.6 ± 3.6 | 16.8 ± 5.9 | .002 | .241 | .013 | .001 |
| Hopkins verbal learning test | 20.5 ± 3.6 | 22.3 ± 3.6 | 15.6 ± 4.3 | <.001 | .190 | <.001 | <.001 |
| Visuospatial function | |||||||
| Clock copying test | 14.0 ± 1.2 | 14.1 ± 1.0 | 13.5 ± 1.1 | .174 | .954 | .098 | .124 |
| Judgment of line orientation | 22.2 ± 3.9 | 23.3 ± 3.6 | 17.2 ± 6.0 | <.001 | .481 | .001 | <.001 |
Note: Data are presented as mean ± SDs unless otherwise indicated. p < 0.05, shown in bold.
Abbreviations: HC, healthy control; LSD, least significance difference; NA, not available; PD, Parkinson's disease; PD‐M, PD with mild cognitive impairment; PD‐N, PD with normal cognition.
a
p value for the gender distribution in the three groups was obtained using a χ 2 test.
b
p values were obtained using two‐sample t tests between PD‐N and PD‐M.