Table 2.
Differences in MRI results between PD and PD-CI groups
| Index | PD-CI | PD | P | Significant difference, Wilcoxon test |
| Hippocampal volume-Left (mm3) | 3,009.63 ± 389.71 | 3,663.99 ± 233.33 | < 0.0001 | **** |
| Hippocampal volume-Right (mm3) | 3,110.81 ± 304.87 | 3,729.91 ± 269.84 | < 0.0001 | **** |
| Mean cortical thickness (mm) | 2.26 ± 0.12 | 2.33 ± 0.15 | 0.0705 | Non-significant |
| Thalamus volume-Left (mm3) | 6,107.18 ± 665.29 | 6,459.24 ± 621.93 | 0.0034 | ** |
| Thalamus volume-Right (mm3) | 6,154.53 ± 517 | 6,488.69 ± 549.61 | 0.0021 | ** |
| Total gray matter volume (mm3) | 442,291.69 ± 34,858.14 | 466,231.84 ± 43,389.97 | 0.0135 | * |
| PVH (mm3) | 11,219.12 ± 10,559.17 | 8,419.13 ± 8,473.85 | 0.1790 | Non-significant |
| DWMH (mm3) | 2,261.37 ± 3,844.67 | 1,307.04 ± 2,683.05 | 0.8183 | Non-significant |
*P < 0.05. **P < 0.01. PD: Patients with Parkinson’s disease but without cognitive impairment; PD-CI: patients with Parkinson’s disease and cognitive impairment; MRI: magnetic resonance imaging; PVH: periventricular hyperintensity; DWMH: deep white matter hyperintensity.