TABLE 1.
Demographic, DAT‐SPECT, clinical, and cognitive characteristics of HC and PD groups according to the hemispheric asymmetry of nigrostriatal degeneration
| HC, n = 196 | PD‐left, n = 143 | PD‐right, n = 106 | P value, HC vs. all PD | P value, PD‐left vs. right | |
|---|---|---|---|---|---|
| Demographic and clinical characteristics | |||||
| Age, y | 59.83 (11.25) | 60.30 (9.80) | 59.29 (9.68) | 0.752 | 0.420 |
| Sex, female/male | 69/127 | 50/93 | 45/61 | 0.229 | |
| Education, y | 16.02 (2.96) | 15.64 (3.00) | 15.3 (3.01) | 0.130 | 0.376 |
| Disease duration from symptoms, mo | 5.67 (6.51) | 5.69 (6.72) | 0.986 | ||
| DAT‐SPECT | |||||
| Mean caudate, SBR | 2.99 (0.61) | 2.02 (0.56) | 2.02 (0.53) | <0.001 | 1 |
| Caudate left | 3.00 (0.64) | 1.84 (0.56) | 2.24 (0.56) | <0.001 | <0.001 |
| Caudate right | 2.97 (0.62) | 2.21 (0.60) | 1.80 (0.53) | <0.001 | <0.001 |
| Mean putamen, SBR | 2.16 (0.55) | 0.85 (0.29) | 0.85 (0.29) | <0.001 | 0.954 |
| Putamen left | 2.15 (0.56) | 0.63 (0.24) | 1.06 (0.38) | <0.001 | <0.001 |
| Putamen right | 2.16 (0.57) | 1.06 (0.37) | 0.64 (0.22) | <0.001 | <0.001 |
| CSF markers, pg/mL | |||||
| Aβ42 | 1024.17 (497.45) | 883.84 (359.80) | 1002.21 (517.14) | 0.056 | 0.042 |
| α‐synuclein | 1702.59 (764.83) | 1527.37 (666.30) | 1577.79 (701.31) | 0.033 | 0.578 |
| Total tau | 189.91 (80.45) | 163.53 (53.64) | 177.13 (64.75) | 0.003 | 0.082 |
| p‐tau181 | 16.84 (8.54) | 13.95 (4.90) | 14.92 (5.93) | <0.001 | 0.172 |
| Aβ42:total tau ratio | 5.59 (1.65) | 5.49 (1.46) | 5.68 (1.68) | 0.891 | 0.366 |
| Motor characteristics | |||||
| MDS‐UPDRS III | 19.02 (8.62) | 22.3 (8.51) | 0.003 | ||
| MDS‐UPDRS III –asymmetry subscores | |||||
| Left side | 2.76 (3.48) | 12.17 (4.3) | <0.001 | ||
| Right side | 10.23 (3.95) | 3.39 (3.38) | <0.001 | ||
| Cognitive characteristics | |||||
| MoCA | 28.07 (1.14) | 27.10 (2.29) | 26.86 (2.52) | <0.001 | 0.422 |
| Benton JLO a | 26.17 (4.03) | 25.65 (4.08) | 25.47 (4.30) | 0.286 | 0.939 |
| HVLT‐R Immediate Recall a | 26.08 (4.57) | 24.88 (5.12) | 24.25 (4.41) | 0.004 | 0.391 |
| HVLT‐R Delayed Recall a | 9.28 (2.36) | 8.58 (2.48) | 8.15 (2.36) | <0.001 | 0.154 |
| HVLT‐R Recognition a | 11.48 (0.83) | 11.24 (1.34) | 11.16 (1.17) | 0.026 | 0.965 |
| LNS a | 10.85 (2.64) | 10.44 (2.81) | 10.75 (2.46) | 0.460 | 0.458 |
| SDMT a | 46.99 (10.64) | 41.18 (8.76) | 43.37 (10.71) | <0.001 | 0.017 |
| Semantic fluency a | 52.09 (11.31) | 48.52 (12.24) | 48.53 (11.33) | 0.004 | 0.909 |
Note. Values represent mean (standard deviation). Significant results are reported in bold.
HC, n = 185; PD‐right, n = 102; and PD‐left, n = 137.
Abbreviations: DAT, dopamine transporter; SPECT, single‐photon emission computed tomography; HC, healthy controls; PD, Parkinson's disease; SBR, specific binding ratio; CSF, cerebrospinal fluid; Aβ42, β‐amyloid; p‐tau181, tau phosphorylated at the threonine; MDS‐UPDRS III, Movement Disorder Society Unified Parkinson's Disease Rating Scale motor score; MoCA, Montreal Cognitive Assessment; JLO, Judgment of Line Orientation; HVLT‐R, The Hopkins Verbal Learning Test–Revised; LNS, Letter Number Sequencing; SDMT, Symbol Digit Modalities Test.