Correlations of brain MRI parameters to disability in multiple sclerosis

Objectives - The objective was to correlate magnetic resonance imaging (MRT ) T-2-weighted lesion load and measures of white matter atrophy in the brai n to disability in a population-based sample of patients with multiple scle rosis (MS). Material and Methods - A well defined cohort of patients was dr awn at random from the general MS population by using the Danish Multiple S clerosis Reigistry. A semi-automated local thresholding technique was used to quantify T-2-weighted lesions on MRI; whereas manual tracing was applied to measure the corpus callosum brain ratio (CCR) and the ventricle brain r atio (VBR). Results - A sample of 86 patients with a mean age of 43.3 years (SD 4.3), mean disease duration of 13.6 years (SD 4.4) and a median Expand ed Disability Status Score (EDSS) of 6.0 was identified. The correlation be tween total lesion area of the brain (TLA) and disability (EDSS) for the wh ole sample was moderate (Spearman rank correlation coefficient r = 0.48, P <0.001). Also correlations of CCR and VER to disability (r = 0.32-0.46) wer e significant. Conclusions - Correlations of TLA and disability in this stu dy were rather strong. Hence, T-2-weighted MRI lesion load in the brain sti ll plays an important role as a surrogate marker of disease and as a second ary outcome measure in phase III treatment trials.