MRI correlates of disease course and activity in multiple sclerosis

We have carried out a comparative cross-sectional study of patients with relapsing and remitting MS (multiple sclerosis) (RRMS) (n=9), primary progressive MS (PPMS) (n=7), and secondary progressive MS (SPMS) (n=10) using image analysis techniques to determine the number and volume of Gd-DTPA-enhancing lesions. RRMS patients had more lesions than either PPMS or SPMS (ns), and the mean volume of the lesions (p=0.006) and the total volume of enhancing lesions (pp<0.003). Differences between PPMS and RRMS/SPMS patients in the volume of the enhancing lesions may reflect differences in the ability of these patients to suppress the immune-mediated damage to axons which may follow episodic BBB breakdown and which is not visualized on conventional magnetic resonance imaging.