Voxel-based diffusion tensor imaging detects pyramidal tract degeneration in primary lateral sclerosis

Abstract

Primary lateral sclerosis (PLS) is a progressive degenerative disorder affecting upper motor neurons and requires a clinical diagnosis. Diffusion tensor imaging (DTI) is a quantitative method for assessing white matter fibre integrity. The purpose of the study was to evaluate the involvement of upper motor neurons by using DTI in PLS. A patient with PLS was compared with eight age-matched controls. Differences in fractional anisotropy (FA) index were assessed using DTI on a voxel-by-voxel basis. Decreased FA was observed in the proximal part of the pyramidal tract bilaterally, which indicated degeneration of the pyramidal cells. Voxel-based DTI could be used as an objective marker for detecting upper motor neuron degeneration in PLS.