Neocortical atrophy, third ventricular width, and cognitive dysfunction in multiple sclerosis.

BACKGROUND Cognitive dysfunction is common in multiple sclerosis (MS). Correlations are reported between atrophy and neuropsychological test results. OBJECTIVE To determine if neocortical volume would supplant or supplement third ventricular width and other magnetic resonance imaging measures when predicting neuropsychological impairment. DESIGN Cross-sectional study. SETTING University MS clinic. PARTICIPANTS Seventy-seven patients with relapsing-remitting MS, 42 patients with secondary progressive MS, and 27 healthy control subjects. MAIN OUTCOME MEASURES Brain atrophy and lesion burden measures were obtained in all patients. A subset of 82 patients and all controls underwent neuropsychological testing. RESULTS Patients with secondary progressive MS had more atrophy than patients with relapsing-remitting MS and controls. Neocortical volume was significantly correlated with all neuropsychological measures, with r values ranging from 0.29 to 0.58. Third ventricular width was retained in most stepwise regression analyses predicting cognitive impairment in patients with MS and distinguishing secondary progressive from relapsing-remitting courses of MS. CONCLUSIONS We confirm an association between neocortical volume and multiple cognitive domains in MS, although neocortical volume did not explain significantly more variance than other magnetic resonance imaging measures. Of the magnetic resonance imaging variables studied, third ventricular width was retained in most regression models.