TABLE 7.
Correlational analyses of total ICARS scores and sensorimotor outcomes (Spearman ρ values).
| 2 s (“Rapid”) | 8 s (“Sustained”) | ||||||
| MVC level | MVC level | ||||||
| Dependent variable | 15% | 45% | 85% | 15% | 45% | 85% | |
| Dominant hand | Rise phase reaction time | 0.52∗ | 0.70∗∗ | 0.67∗∗ | 0.61∗∗ | 0.18 | 0.34 |
| Rate of force increase | 0.09 | 0.11 | 0.30 | –0.09 | –0.16 | 0.11 | |
| Rise phase duration | –0.05 | –0.11 | –0.09 | –0.21 | 0.07 | 0.09 | |
| Rise phase accuracy | –0.21 | –0.04 | –0.23 | –0.11 | 0.12 | –0.42 | |
| ApEn | − | − | − | –0.18 | 0.02 | –0.20 | |
| Force SD | − | − | − | 0.22 | 0.40 | 0.41 | |
| Mean force | − | − | − | 0.14 | 0.08 | 0.09 | |
| Rate of force relaxation | –0.39 | –0.43 | –0.44 | –0.27 | –0.16 | –0.10 | |
| Non-dominant hand | Rise phase reaction time | 0.46 | 0.52∗ | 0.67∗∗ | 0.37 | 0.44 | 0.25 |
| Rate of force increase | –0.11 | –0.04 | –0.07 | –0.22 | –0.05 | –0.09 | |
| Rise phase duration | –0.22 | –0.13 | –0.19 | −0.20×10−2 | 0.13 | −0.20×10−2 | |
| Rise phase accuracy | –0.10 | 0.19 | 0.03 | –0.04 | 0.22 | –0.43 | |
| ApEn | − | − | − | –0.40 | –0.17 | –0.38 | |
| Force SD | − | − | − | 0.34 | 0.66∗∗ | 0.58∗ | |
| Mean force | − | − | − | 0.09 | 0.14 | 0.11 | |
| Rate of force relaxation | –0.34 | –0.03 | 0.02 | 0.12 | –0.01 | 0.38 | |
MVC: maximum voluntary contraction; ICARS: International Cooperative Ataxia Rating Scale; ∗p < 0.05; ∗∗p < 0.01. Rates of force relaxation are negative values, and so positive correlations indicate that an increase in CGG repeat length is associated with slower (i.e., less negative) rates of force relaxation.