MRI-based cerebellar volume measurements correlate with the International Cooperative Ataxia Rating Scale score in patients with spinocerebellar degeneration or multiple system atrophy

Daisuke Hara, Futaba Maki, Shigeaki Tanaka, Rie Sasaki, Yasuhiro Hasegawa

Progression of clinical symptoms and cerebellar atrophy may vary among subtypes of spinocerebellar degeneration and multiple system atrophy. The aim of this cross-sectional study was to demonstrate the relationship between the International Cooperative Ataxia Rating Scale (ICARS) score and cerebellar volume derived from magnetic resonance imaging (MRI) in a broad spectrum of Japanese patients with cerebellar ataxia. A total of 86 patients with cerebellar ataxia (18 with cortical cerebellar atrophy, 34 with spinocerebellar ataxia, and 34 with multiple system atrophy) and 30 healthy subjects were studied. MRI-based cerebellar volume measurements were performed in all subjects using T1-weighted images acquired with a 1.5-T MRI scanner. The cerebellar volume/cranial anteroposterior (AP) diameter was used for statistical analysis. Stepwise multiple regression analyses demonstrated that cerebellar volume/cranial AP diameter and midbrain AP/cranial AP diameter were significantly associated with the total score and domain I sub-score of ICARS. We found no interactions between these two anatomical factors in the ICARS total and domain I sub-scores. The main effects of these two predictors were statistically significant both in total and domain I sub-scores (p = 0.001 and 0.022, respectively). Cerebellar volume and midbrain AP diameter normalized to the cranial AP diameter were significantly correlated with the ICARS total and domain I sub-scores. Further longitudinal studies are warranted to explore the role of these MRI biomarkers for predicting disease progression.