Article Provided by: PubMed
Article Date: 04 Aug 2008
Engineering Department, Montreal Neurological Institute, McGill
University, Montreal, Canada. email@example.com.
The pathogenesis of tissue injury outside the white matter (WM) plaques
of multiple sclerosis (MS) has not yet been clearly defined. To better
understand the pathogenesis of this injury and the associated atrophy,
we investigated volume loss over time in 20 WM fiber tracts. We defined
two main aims: (1) to examine whether certain fiber tracts were more
prone to atrophy, and to test the possible relation of tract atrophy to
tract length and selected MS-specific variables; and (2) to investigate
the possible relation of atrophy to lesion load (whole brain and in the
specific tract). Local volume change was assessed between two distant
time points for each MS patient studied. Fiber tracts were segmented
automatically using a tractography-based atlas. Results demonstrate
volume loss in all fiber tracts. The uncinate fasciculus and
anterior-thalamic radiation had the greatest yearly percentage atrophy.
Disease type, duration, median expanded disability status scale, total
lesion load, and gender exhibited significant effects on atrophy in at
least one tract. Together, these data are more consistent with a
pathogenesis for the degeneration related to diffuse inflammation
rather than the secondary effects of focal lesions.