Table 1. Demographic characteristics and cognitive performance for different PD groups and normal controls.
| Mean ± SD or % | Normal controls (n = 20) |
PD-CN (n = 19) |
p-valuea | PD-aMCI (n = 17) |
p-valueb |
| Age, years | 59.5±6.2 | 61.3±6.9 | 0.41 | 64.9±5.9 | 0.11 |
| Gender (% male) | 80% | 78.9% | 0.94 | 88.2% | 0.46 |
| Education, years | 9.3±2.2 | 10.3±3.3 | 0.29 | 9.6±3.8 | 0.60 |
| Disease duration, years | / | 5.9±3.4 | / | 7.6±4.9 | 0.23 |
| Hoehn and Yahr stage | / | 1.5±0.8 | / | 1.9±0.8 | 0.14 |
| UPDRS-III score | / | 17.7±9.7 | / | 24.4±11.2 | 0.07 |
| Levodopa equivalent daily dose (mg) | / | 917.0±144.6 | / | 942.1±120.6 | 0.58 |
| MMSE score | 29.5±0.4 | 29.4±0.8 | 0.63 | 28.5±1.4 | 0.09 |
| RBANS index scores | |||||
| Immediate memory | 113.6±7.9 | 108.8±10.2 | 0.12 | 74.2±8.1 | <0.001 |
| Delayed memory | 112.1±9.7 | 109.3±9.0 | 0.38 | 75.4±10.1 | <0.001 |
| Attention | 106.2±10.5 | 100.5±7.6 | 0.07 | 92.2±11.2 | 0.02 |
| Language | 104.8±7.1 | 99.8±11.3 | 0.12 | 94.6±7.3 | 0.11 |
| Visuospatial function | 102.3±11.3 | 100.6±13.2 | 0.68 | 96.6±12.6 | 0.36 |
PD = Parkinson’s disease; PD-aMCI = amnestic mild cognitive impairment in PD; PD-CN = cognitively normal PD patient; UPDRS-III = the Movement Disorder Society modified version of the Unified Parkinson’s Disease Rating Scale–part III for motor examination; MMSE = Mini-Mental State Examination. The differences between PD-CN and normal controls, as well as between PD-aMCI and PD-CN in the variables were examined, and the significance values were indicated by p-valuea and p-valueb, respectively.