Striatal microstructural abnormalities in Huntington’s disease revealed by soma and neurite density imaging

Motivation: Huntington's disease (HD) is an inherited neurodegenerative condition with no disease-modifying therapies currently available. Goal(s): To assess whether advanced diffusion MRI (dMRI) modelling of grey matter microstructure can detect striatal degeneration in HD and provide new in-vivo biomarkers for future clinical trials. Approach: Applied Soma And Neurite Density Imaging (SANDI) to dMRI data at ultra-strong gradients from 56 HD patients and 57 matched controls. Results: HD patients showed lower apparent soma density and larger soma size in the basal ganglia, consistent with histological evidence of striatal degeneration and glial swelling. Differences in SANDI indices correlated with motor impairments. Impact: Soma and Neurite Density Imaging (SANDI) is sensitive to striatal neurodegeneration in Huntington's disease (HD). SANDI indices have the potential for in vivo biomarkers of HD pathology and surrogate clinical outcome measures for disease-modifying therapeutics in future clinical trials.