We examined quantitative relationships between tissue damage in the cervical spinal cord (characterized by cross-sectional area (CSA)) and cortical gray matter (GM) (characterized by thickness and tissue specific R2* values) in multiple sclerosis (MS) patients, and determined relative contributions of these to neurologic disability. We found correlations between CSA and GM R2* values and thickness of several cortical regions. Compared with cortical R2* and thickness, cervical spinal cord CSA correlated better with neurological impairment status. CSA, thickness and age-corrected R2* values all differentiated MS subjects from healthy Controls. CSA and GM thickness could further distinguish MS clinical subtypes.