Study – MS Brain Atrophy                                           

Brain Atrophy Occurs Earlier Than Expected in MS

This study suggests that brain and spinal-cord atrophy may occur earlier in the course of multiple sclerosis than has been thought.

Patients with multiple sclerosis (MS) develop irreversible CNS tissue injury, the end result of which is brain and spinal-cord atrophy.  Atrophy was thought to occur late in the course of MS because, despite periodic relapses, patients function normally for years after symptomatic onset of MS.  To study brain atrophy in early MS, these researchers used quantitative cranial MRI scans to examine

In patients with MS, symptoms had been present for an average of only 1.8 years, and the patients had normal neurologic function.

Compared with controls, MS patients had significantly reduced brain parenchymal (The tissue characteristic the brain) fraction (BPF) -- a measure of whole-brain atrophy -- and reduced gray-matter (GM) and white-matter (WM) fractions (average age- and sex-adjusted reductions, about 3.5% for BPF, about 2.8% for GM, and about 4.9% for WM).

Significant correlations were found between T2 hyperintense or T1 hypointense lesion volumes and whole-brain or GM atrophy, but there were no significant correlations between lesions and WM atrophy. The authors conclude that brain atrophy occurs early in MS patients and speculate that factors contributing to WM atrophy might differ from factors contributing to GM atrophy.

Comment by Dr. Rudick:

This addition to the growing literature on brain atrophy in MS focuses attention on irreversible brain pathology that can be detected early in the disease.  The study emphasizes our limited understanding of factors contributing to brain-atrophy progression. Visible T2 or T1 lesions explained only a minority of the variance in whole-brain or GM atrophy, and none of the variance in WM atrophy, among participants in this study.

Patients with early MS probably have normal neurologic function despite significant brain atrophy because the destructive pathologic process continues for a long time before function is compromised.  The findings of the current study imply that patients should be treated early with disease-modifying drugs and that atrophy measures should be included in clinical trials and, perhaps, in clinical practice.  The findings also imply an urgent need to identify factors related to brain and spinal-cord atrophy in MS.

— Richard A. Rudick, MD

Dr. Rudick is Director, Mellen Center for Multiple Sclerosis, Department of Neurology, and Director, Center for Clinical Research, Cleveland Clinic Foundation, Cleveland.

Published in Journal Watch Neurology May 10, 2002