Table 3.
Mean and standard deviation performance metrics for pre‐SCA3, SCA3 and control groups on the oculomotor parameters
| Oculomotor signs | Pre‐SCA3 | SCA3 | NC | P | Post hocs |
|---|---|---|---|---|---|
| Fixation stability | |||||
| Frequency of SWJ (Hz) | 0.54±0.47 | 0.79±0.56 | 0.06±0.13 | <.0001 | NC<Pre‐SCA3, SCA3 |
| Average amplitude of SWJ (°) | 1.15±0.77 | 1.53±0.93 | 0.23±0.43 | <.0001 | NC<Pre‐SCA3, SCA3 |
| Gaze | |||||
| Frequency of horizontal GEEM (Hz) | 0.83±0.5 | 1.65±0.75 | 0.09±0.15 | <.0001 | SCA3>Pre‐SCA3>NC |
| Average amplitude of horizontal GEEM (°) | 1.60±0.66 | 3.40±2.30 | 0.31±0.55 | <.0001 | SCA3>Pre‐SCA3>NC |
| Frequency of horizontal SWJ evoked by upward gaze (Hz) | 0.63±0.52 | 1.03±0.70 | 0.07±0.15 | <.0001 | NC<Pre‐SCA3, SCA3 |
| SPEM | |||||
| Horizontal mean pursuit gain (%) | 81.3±8.0 | 69.4±10.8 | 87.9±4.1 | <.0001 | NC, Pre‐SCA3>SCA3 |
| Vertical mean pursuit gain (%) | 64.4±18.2 | 67.8±15.4 | 81.8±4.5 | .0003 | NC>Pre‐SCA3, SCA3 |
| Prosaccade | |||||
| Upward saccade latency (milliseconds) | 200±27.6 | 205±36.5 | 203±23.2 | >.05 | NC=Pre‐SCA3=SCA3 |
| Horizontal peak saccade velocity (°/seconds) | 529±66.0 | 527±130.3 | 524±56.9 | >.05 | NC=Pre‐SCA3=SCA3 |
| Upward peak saccade velocity (°/seconds) | 424±81.6 | 338±109.3 | 563±100.5 | <.0001 | SCA3<Pre‐SCA3<NC |
| Horizontal saccadic accuracy (%) | 98.4±3.7 | 92.8±16.9 | 98.2±3.5 | >.05 | NC=Pre‐SCA3=SCA3 |
| Upward saccadic accuracy (%) | 93.0±9.0 | 85.1±16.0 | 94.4±7.4 | .0135 | SCA3<NC |
| Antisaccade | |||||
| Total antisaccadic error rate (%) | 36.4±24.1 | 66.8±22.9 | 19.2±14.0 | <.0001 | SCA3>Pre‐SCA3>NC |
Pre‐SCA3, preclinical SCA3; SCA3, spinocerebellar ataxia type 3; NC, normal controls; SWJ, square‐wave jerk; GEEM, gaze‐evoked eye movement; SPEM, smooth pursuit eye movement.
Oculomotor parameters are given as mean±SD.