SACS and Charlevoix-Saguenay spastic ataxia: Intermediate filament remodelling is a hallmark of ARSACS pathogenesis, with abnormal bundles of vimentin in fibroblasts of patient with ARSACS15 and of neurofilaments in brain autopsies of patients with ARSACS and in the Sacs−/− mouse.8,16 While in the controls vimentin appeared evenly distributed in the cells, in PN6 and PN7 we observed abnormal reorganization of vimentin filaments, which appear to form bundles or to be more densely packed at the periphery and were indistinguishable between the two patients (Fig. 3C and D).