Utility of two biomarkers measured by MRI diffusion tensor for the differential diagnosis between early Parkinson’s disease and atypical parkinsonism.

Abstract

Objective: to determine the usefulness of the quantitative analysis of structural and volumetric changes at the level of the substantia nigra on magnetic resonance studies by fractional anisotropy and mean diffusivity to differentiate between patients with early Parkinson’s disease , atypical parkinsonism and healthy controls. Material and methods: we included a total of 10 patients with early Parkinson’s disease, 11 patients with atypical parkinsonism and 10 healthy controls. Fractional anisotropy and mean diffusivity were measured, after obtaining conventional diffusionweighted magnetic resonance sequences. Results: fractional anisotropy in the caudate nucleus allowed to differentiate between patients with atypical parkinsonism group and the healthy control group. Mean diffusivity in the caudate nucleus allowed differentiation between the group of patients with atypical parkinsonism and healthy controls, as well as Parkinson’s disease group from healthy control group. Neither the fractional anisotropy or mean diffusivity in the targets chosen was able to differentiate between atypical parkinsonism and patients with early Parkinson’s. Conclusions: the magnetic resonance biomarkers used were only useful to discriminate healthy subjects from those with atypical parkinsonism or Parkinson’s disease.