Table 2. Cross-sectional comparison of digitomotography measures between early patients with PD, mid-stage PD and controls.
| Controls | Early PD | Mid-stage PD | P-value | |
|---|---|---|---|---|
| Averaged values | ||||
| IPI mean [s] | 0.28 (0.05) | 0.32 (0.12) | 0.29 (0.07) | 0.15 |
| IPI SD [s] | 0.024 (0.01) | 0.044°° (0.03) | 0.041° (0.03) | 0.03 |
| TF mean [N] | 2.68 (1.95) | 1.30 (0.62) °° | 2.00 (1.12) | 0.009 |
| TF CoV | 0.23 (0.06) | 0.30 (0.13) | 0.27 (0.09) | 0.06 |
| DEV mean [s] | 0.027 (0.02) | 0.049 (0.05) | 0.064 (0.07) °° | 0.046 |
| DEV SD [s] | 0.048 (0.01) | 0.061 (0.02) °° | 0.058 (0.02) ° | 0.03 |
| Lateralization | ||||
| IPI mean [s] | 0.030 (0.037) | 0.078 (0.113) | 0.059 (0.062) | 0.095 |
| IPI SD [s] | 0.014 (0.018) | 0.018 (0.025) | 0.035 (0.059) | 0.12 |
| TF mean [N] | 0.65 (0.46) | 0.53 (0.46) | 0.53 (0.54) | 0.35 |
| TF CoV | 0.036 (0.026) | 0.088 (0.075) ° | 0.104 (0.094) °° | 0.008 |
| DEV mean [s] | 0.016 (0.017) | 0.035 (0.050) | 0.021 (0.017) | 0.10 |
| DEV SD [s] | 0.012 (0.011) | 0.025 (0.024) °° | 0.010 (0.009) ** | 0.008 |
Data are presented with mean (standard deviation). Statistical comparisons were performed with ANOVA (right column). Results of analyses between single cohorts (controls versus early Parkinson’s disease (PD), controls versus mid-stage PD, early PD versus mid-stage PD) are displayed as follows: Compared to controls without ° and with °° Bonferroni correction (p < 0.05/3 = 0.017).
** Compared to early PD with Bonferroni correction.
CoV, coefficient of variation; DEV mean, mean tap deviation from the predefined 1.55 Hertz cueing tone; DEV SD, variability of tap deviation from the predefined 1.55 Hertz cueing tone; IPI, interpeak interval; SD, standard deviation; TF, tap force.