Large, nonplateauing relationship between clinical disability and cerebral white matter lesion load in patients with multiple sclerosis.

Objective: To better characterize the relationship between cerebral white matter lesion load (CWM-LL) and clinical disability by (1) covering the entire range of the Kurtzke Expanded Disability Status Scale (EDSS), (2) minimizing nonbiological sources of variability, and (3) increasing pathologic specificity by studying CWM lesions that are hypointense on T1-weighted magnetic resonance imaging.

Design: Cross-sectional, retrospective study.

Setting: Hospital-based multiple sclerosis (MS) clinic.