Table 2. Prevalence of eye movement abnormalities in patients with SCA.
| SCA 1 (n = 56) (P) | SCA 2 (n = 69) (P) | SCA 3 (n = 119) (P) | SCA 6 (n = 72) (P) | P-Value Comparing All SCAs | |
|---|---|---|---|---|---|
| Diplopia | 24 (0.010) | 18 (<0.001) | 61 (<0.001) | 43 (0.70) | <0.001 |
| GEN | 44 (0.067) | 13 (<0.001) | 77 (<0.001) | 78 (<0.001) | <0.001 |
| Hypermetric saccades | 41 (0.67) | 14 (<0.001) | 50 (0.042) | 51 (0.056) | <0.001 |
| Hypometric saccades | 20 (0.13) | 28 (0.81) | 34 (0.038) | 21 (0.19) | 0.17 |
| Slow saccades | 47 (0.49) | 80 (<0.001) | 40 (0.31) | 11 (<0.001) | <0.001 |
| Horizontal ophthalmoparesis | 22 (0.63) | 15 (0.22) | 35 (<0.001) | 2 (<0.001) | <0.001 |
| Vertical ophthalmoparesis | 28 (0.67) | 25 (0.46) | 47 (<0.001) | 6 (<0.001) | <0.001 |
| Abnormal smooth pursuit | 45 (0.019) | 37 (<0.001) | 70 (0.023) | 79 (0.001) | <0.001 |
| Square-wave jerks | 11 (0.14) | 5 (0.019) | 23 (0.004) | 17 (0.87) | 0.012 |
Values are reported as % (P). The P-value is a comparison of that particular SCA against all other SCAs, as calculated with a χ2 test. The final column represents the P-value in comparing each individual SCA, as calculated with a 4-group χ2 test.
GEN, gaze-evoked nystagmus; SCA, spinocerebellar ataxia.