This study group from the Netherlands looked at the extent and severity of white matter (WM) damage, using diffusion tensor imaging (DTI), to distinguish cognitively preserved (CP) from cognitively impaired (CI) MS patients. Using MRI and DTI from 35 CP, 20 CI and 30 healthy controls, they investigated fractional anisotropy (FA), mean diffusivity, radial diffusivity and axial diffusivity of a WM skeleton.
They found decreased FA in 49% of the investigated WM in CP patients and 76% in CI patients. Both groups showed reduced FA in the corpus callosum, superior and inferior longitudinal fasciculus, corticospinal tracts, cingulum and fornices, but it was significantly worse in the CI group. Additional damage was seen in the thalamus, cortical areas, brainstem and cerebellum in CI patients.
Therefore, this study shows that WM integrity changes were found in areas which are highly relevant for cognition in the CI patients. These white matter changes are likely to be related to the cognitive deficits, which raises the possibility of DTI being a useful tool for monitoring cognitive impairment in MS.
Authors: Hulst HE, Steenwijk MD, Versteeg A
Source: Neurology. 2013 Mar 6. [Epub ahead of print]
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