BACKGROUND AND PURPOSE: This study employs magnetic resonance imaging (MRI) diffusion tensor imaging to compare diffusion measures in the brains of @entity1 with @entity191 ( @entity191 ) with healthy controls using longitudinal data. METHODS: One-hundred and twenty-two @entity1 and 34 controls were included at baseline. The MRI investigations were repeated after 1, 3 and 5  years. The diffusion measures were quantified using fractional anisotropy and mean, radial and axial diffusion (FA, @entity601 , RD, @entity195 ). Regions of interest included the anterior, middle and posterior substantia nigra (SN), but also other areas. Linear models were used to test for the effect of disease and hemispheric lateralization. The P value was set at 0.05 (Bonferroni corrected). RESULTS: Fractional anisotropy and @entity195 were increased in the three nigral subareas in @entity191 (P  <  0.01), but @entity601 and RD were unaltered. The right SN had higher FA than the left in all subareas (P  <  0.01). @entity601 and @entity195 were increased in the right anterior part (P  <  0.04), whereas @entity601 and RD were decreased in the right middle and posterior parts (P  <  0.001). The left middle cerebellar peduncle had increased FA and @entity195 (P  <  0.001) and decreased @entity601 and RD (P  <  0.01) compared to the right. Diffusion measures did not progress over time and side differences were not related to disease or lateralization of symptoms. CONCLUSIONS: Increased FA in the SN in @entity191 indicates @entity5219 and @entity32 in the nuclei, but possibly also intrusion of surrounding fibres into the shrinking structure. The hemispheric side differences of diffusion might reflect natural lateralization of connectivity, but their relation to @entity191 must be studied further.

Fractional anisotropy in the substantia nigra in XXXX : a complex picture.

@entity1 :: ('9606', 'Species') :: ['patients'] @entity32 :: ('MESH:D007249', 'Disease') :: ['inflammation'] @entity5219 :: ('MESH:D005911', 'Disease') :: ['gliosis'] @entity191 :: ('MESH:D010300', 'Disease') :: ["Parkinson's disease", 'PD'] @entity601 :: ('MESH:D009436', 'Disease') :: ['MD'] @entity195 :: ('MESH:D000544', 'Disease') :: ['AD']
@entity191 :: (MESH:D010300,Disease) :: ['Parkinson's disease']
