Table 2 Patient characteristics by clusters
|  | Total (n = 48) | Cluster 1 (n = 12) | Cluster 2 (n = 22) | Cluster 3 (n = 14) | p value |
|---|---|---|---|---|---|
Age at the first MRI (years) | 60.5 ± 11.3 | 66.3 ± 8.5 | 60.4 ± 12.0 | 56.0 ± 10.6 | 0.088 |
Sex (Male/Female) | 24/24 | 7/5 | 8/14 | 9/5 | 0.211 |
Diagnosis | |||||
 SCA, n (%) | 21 (43.8) | 6 (50.0) | 11 (50) | 4 (28.6) | 0.007 |
  SCA1 | 3 | 0 | 3 | 0 |  |
  SCA2 | 3 | 1 | 1 | 1 |  |
  SCA3 | 4 | 0 | 1 | 3 |  |
  SCA6 | 6 | 2 | 4 | 0 |  |
  SCA31 | 1 | 1 | 0 | 0 |  |
  SCA (unknown) | 4 | 2 | 2 | 0 |  |
 MSA-C, n (%) | 17 (35.4) | 0 (0.0) | 9 (40.9) | 8 (57.1) |  |
 CCA, n (%) | 10 (20.8) | 6 (50.0) | 2 (9.1) | 2 (14.3) |  |
ICARS score at the first visit | 35.5 ± 16.5 | 39.1 ± 7.4 | 35.2 ± 22.2 | 30.0 ± 16.1 | 0.464 |
Initial cerebellar volume index (Vdx) | 0.47 ± 0.09 | 0.45 ± 0.08 | 0.45 ± 0.10 | 0.50 ± 0.07 | 0.275 |
Annual atrophy volume in Vdx | −0.04 ± 0.02 | 0.02 ± 0.01* | −0.04 ± 0.01 | −0.07 ± 0.02 | 0.001 |
Initial callosal area index (Adx) | 3.38 ± 0.45 | 3.13 ± 0.39 | 3.53 ± 0.37‡ | 3.28 ± 0.46 | 0.011 |
Annual atrophy area in Adx | −0.11 ± 0.08 | −0.04 ± 0.03†| −0.10 ± 0.05†| −0.19 ± 0.09†| 0.001 |
Annual increase in ICARS score | 4.4 ± 4.5 | 2.9 ± 1.7 | 4.8 ± 3.2 | 8.7 ± 6.1 | 0.014 |