Cognitive correlates of supratentorial atrophy on MRI in multiple sclerosis

We aimed to investigate associations between neuropsychological indices and normalized volumes of supratentorial structures, and the area of the corpus callosum. Materials and methods - We studied 40 patients with clinically definite MS, using 3D-acquired MRI (MPRAGE, Magnetization Prepared Rapid Acquisition Gradient Echo) and stereology. Subjects underwent a neuropsychological battery interrogating multiple cognitive domains, from which a global Cognitive Index Score (CIS) was derived. Results - White matter Volumes were significantly correlated with CIS (rho= -0.59, P <0.0001) and with many of the individual cognitive tests. CIS was also significantly correlated with the corpus callosal area (rho = - 0.49, P <0.002). Grey matter volumes did not significantly correlate with any cognitive test. Conclusions - These volume/function relationships presumably reflect the effects of subcortical axonal and myelin loss on the neural networks that subserve cognition. If serial MRI volume estimations can index accumulating cognitive deficits, this simple technique may be useful in therapeutic trials.