Table 3.
Significant coefficients (β) of the GLM regression of DTI metrics with clinical covariates.
| Description | AAO(β) | GAAsr(β) | ICARS(β) | SARA(β) | FARS-ne (β) |
|---|---|---|---|---|---|
| FA | |||||
| Anterior thalamic radiation L | 0.0035 | – | – | – | – |
| Anterior thalamic radiation R | 0.0032 | – | – | – | – |
| Posterior thalamic ratiation and retrolenticular part of IC R | 0.0050 | – | – | – | – |
| Posterior thalamic ratiation and retrolenticular part of IC L | 0.0060 | – | – | – | −0.0010 |
| Forceps major | 0.0059 | −0.0001 | −0.0013 | −0.0029 | – |
| Inferior fronto–occipital fasciculus R | 0.0039 | – | – | – | – |
| Body of CC | 0.0071 | – | – | – | – |
| Anterior limb of IC L | 0.0049 | – | – | – | – |
| Fornix (column, body, cres with stria terminalis) | 0.0051 | – | – | −0.0028 | – |
| SCP R | – | −0.0001 | −0.0016 | −0.0040 | −0.0016 |
| SCP L | – | −0.0001 | −0.0012 | −0.0032 | −0.0012 |
| MD | |||||
| Anterior thalamic radiation L | −0.0283 | – | – | – | – |
| Anterior thalamic radiation R | −0.0332 | – | – | – | – |
| Posterior thalamic ratiation and retrolenticular part of IC L | −0.0347 | – | – | – | – |
| CST R | −0.0280 | – | – | – | – |
| Forceps major | −0.0360 | – | – | 0.0181 | – |
| Inferior fronto–occipital fasciculus R | −0.0200 | – | – | – | – |
| Superior longitudinal fasciculus L | −0.0229 | – | – | – | – |
| Superior longitudinal fasciculus R | −0.0200 | – | – | – | – |
| Splenium of CC | −0.0322 | – | – | – | – |
| Fornix (column, body, cres with stria terminalis) | – | – | – | 0.0220 | 0.0095 |
| ICP R | −0.0322 | – | – | – | – |
| SCP R | – | – | 0.0137 | 0.0334 | 0.0132 |
| SCP L | – | – | 0.0120 | 0.0313 | 0.0119 |
p < 0.05/nr of covariates. FA, Fractional anisotropy; MD, medial diffusivity; FRDA, Friedreich's ataxia patients; SCP, superior cerebellar peduncle; L, left; R, right; ICP, inferior cerebellar peduncle; CST, cortical spinal tract; AAO, age at onset; GAAsr, GAA short-allele; SARA, Scale for the Assessment and Rating of Ataxia (0–40); ICARS, International Cooperative Ataxia Rating Scale (0–100); FARS-ne, Friedreich Ataxia Rating Scale -neurological examination (0–117).