MR of the spinal cord in multiple sclerosis: relation to clinical subtype and disability.

Purpose: To determine whether the MR appearance of the spinal cord in patients with multiple sclerosis (MS) differs according to clinical subtype.
Methods: The spinal cords of 20 healthy control subjects and 60 patients with MS (22 with relapsing-remitting disease, 22 with secondary-progressive disease, and 16 with primary-progressive disease) were examined with sagittal dual-echo spin-echo MR imaging and with axial T2*-weighted gradient-echo MR imaging. Two interpreters scored the images for focal lesions and for diffuse abnormalities. Cross-sectional areas of the cords were measured at the C-2 level.
Results: No abnormalities were found in any of the control subjects nor in two of the patients. Fifty (83%) of 60 patients had focal lesions. Diffuse abnormality and focal lesions were found in 50% of patients with secondary-progressive MS, in 25% of patients with primary-progressive disease, and in 18% of patients with relapsing-remitting disease. Diffuse abnormality without focal lesions was found in seven patients with primary-progressive MS and in one patient with secondary-progressive MS. Patients with diffuse abnormalities had a smaller cross-sectional area of the spinal cord and they suffered from more disability than did patients without diffuse abnormalities.
Conclusion: The MR appearance of the spinal cord differs among clinical subgroups of MS. Diffuse abnormality of the spinal cord is associated with a progressive clinical course and greater disability.