Quantitative diffusion tensor imaging in amyotrophic lateral sclerosis

Abstract

Objective: Aim of present study was to evaluate changes in diffusion tensor imaging (DTI) parameters in the whole brain of 28 patients with amyotrophic lateral sclerosis (ALS) compared to 26 healthy controls.

Methods: In both fibertracking and voxel-based analysis, quantitative comparisons of the diffusion parameters between ALS patients and controls were performed. Correlation analyses of diffusion parameters and disease duration and disease severity were performed. A second DTI examination was acquired, allowing the evaluation of the effect of disease progression on the diffusion parameters.

Results: Fibertracking analysis revealed that especially the precentral part of the corticospinal tract (CST) was impaired. In the voxel-based analysis, it was shown that changes of diffusion parameters occurred throughout the brain, including frontal, temporal and parietal lobes. Disease severity was inversely correlated with the fractional anisotropy (FA). In the follow-up examination, a further decline of FA over time could be demonstrated in the CST as well as in the whole brain white matter.

Interpretation: This study provides support for the view of ALS as being a multisystem degenerative disease, in which abnormalities of extra-motor areas play an important role in the in vivo physiopathology.