Anatomical abnormalities suggest a compensatory role of the cerebellum in early Parkinson's disease.

Brain atrophy is detected in early Parkinson's disease (PD) and accelerates over the first few years post-diagnosis. This was captured by multiple cross-sectional studies and a few longitudinal studies in early PD. Yet only a longitudinal study with a control group can capture accelerated atrophy in early PD and differentiate it from healthy ageing.