Superior cerebellar peduncle diffusivity differentiates progressive supranuclear palsy from other parkinsonian syndromes

Motivation: Overlapping clinical symptoms make differential diagnosis of typical and atypical parkinsonian syndromes difficult in the early stages of these diseases. Goal(s): Our goal was to assess atrophy in the superior cerebellar peduncle in progressive supranuclear palsy. Approach: A high-resolution DTI (voxel size=1.1×1.1×1.1 mm3) was used to derive diffusion metrics in the super cerebellar peduncle in a population of typical and atypical parkinsonian syndromes. Results: Application of this protocol found measures consistent with superior cerebellar peduncle atrophy (increased MD, decreased FA) in the progressive supranuclear palsy relative to the Parkinson’s disease and multiple systems atrophy- with predominant parkinsonian features groups. Impact: Overlapping clinical features makes differential diagnosis of progressive supranuclear palsy from other parkinsonian syndromes difficult in the early stages of these diseases. Our demonstration of superior cerebellar peduncle atrophy in progressive supranuclear palsy suggests imaging markers may aid differential diagnosis.