MR lesion load and cognitive function in patients with relapsing-remittingmultiple sclerosis

BACKGROUND AND PURPOSE: Multiple sclerosis (MS) is a demyelinating disease most often associated with progressive physical impairment; however, its ef fects are noted to extend beyond physical disability, Our purpose was to de termine the relationship between T2 lesion volume and neurocognitive and ph ysical disability in relapsing-remitting multiple sclerosis, METHODS: We studied a cohort of 19 patients with relapsing-remitting MS. Of this group, there were 15 women and four men from varying socioeconomic ba ckgrounds. This volunteer sample was selected from a larger group of 53 pat ients with MS in our longitudinal MS study because they had been untreated with any beta-interferon medications, had been followed for at least 12 mon ths, and had a clinical status of relapsing-remitting MS. RESULTS: Of 12 neurocognitive parameters tested, two correlated significant ly with lesion loads. The correlation of the Symbol-Digit Modalities test, which analyzes information-processing speed, was significant (P = .0204), T he correlation of the fifth trial of the Rey Auditory Verbal Learning test, which tests verbal long-term memory, was also significant (P = .0348), Non e of the other 10 neurocognitive examinations, however, showed a significan t correlation with total lesion volume (Paced Auditory Serial Addition test -1.6, P = .7381; Paced Auditory Serial Addition test-2.0, P = .4180; Contro lled Oral Word Association test, P = .8906; Category Fluency test, P = .442 3; Bells test, P = .9097; Rey Auditory Verbal Learning test-delay, P = .984 3, Rey Auditory Verbal Learning test-recognition, P = .7467; Word Span test , P = .4939; Road Map test, P = 0.4939). The lesion load also did not corre late with the physical disability scales as rated according to the Expanded Disability Status Scale (P = .68) or Ambulation Index (P = .95), CONCLUSION: Our results indicate that T2 lesion volume does not seem to be a robust surrogate marker of neuropsychological impairment in patients with MS. We think that global measurements of parameters that are more specific to the disease process may offer more precise correlation with cognitive d ysfunction and other disability parameters.