Diffusely Abnormal White Matter and Progressive Multiple Sclerosis

Diffusely abnormal white matter (DAWM) can be seen on T2-weighted images in some people with multiple sclerosis (MS) as heterogeneous bright signals with poorly defined borders. As opposed to focal white matter lesions (FWMLs), DAWM has been observed to impact myelin phospholipids. Investigators included 686 participants with relapsing-remitting (RR) MS, and 689 with secondary-progressive (SP) MS followed with imaging for at least 24 months.

Median DAWM volume was higher in SPMS than in RRMS, after correcting for age and disease duration. The yearly average DAWM to FWML conversion rates were 1.27 cm³ for SPMS and 0.80 cm³ for RRMS. Conversion was 5.41% of baseline DAWM volume for SPMS and 4.06% for RRMS. Whereas new FWMLs arose from regions …