Diffusion MRI with spherical tensor encoding at high b-values reveals cerebellar grey matter abnormalities in movement disorders

Most work on understanding movement disorder pathophysiology has focused on grey/white matter volumetric (macrostructural) and white matter microstructural effects, limiting understanding of frequently implicated grey matter microstructural differences. Using ultra-strong diffusion MRI with spherical tensor encoding, a persistent MRI signal was seen in healthy cerebellar grey matter at ultra-high diffusion-weightings. This work quantifies the proportion of this signal, previously ascertained to originate from small spherical spaces, in a clinical cohort, including patients with diagnosed movement disorders where the cerebellum has been implicated in symptom pathophysiology. Significant differences were found in individuals diagnosed with SCA6 and dystonia compared to age-matched controls.