Fluid-attenuated inversion recovery magnetic resonance imaging detects cortical and juxtacortical multiple sclerosis lesions

Background: Autopsy studies showed cortical and juxtacortical multiple scle rosis (MS) plaques. Fluid-attenuated inversion recovery (FLAIR) is an advan ced magnetic resonance imaging sequence that reveals tissue T2 prolongation with cerebrospinal fluid suppression, allowing detection of superficial br ain lesions. Objectives: To assess FLAIR, T1-weighted, and T2-weighted images for detect ing lesions in or near the cerebral cortex in patients with MS and to explo re the relation between cortical lesions and cortical atrophy. Design, Setting, and Patients: Cross-sectional study in a university MS cli nic of 84 patients with MS and 66 age-matched healthy controls receiving 1. 5-T fast FLAIR, T2-weighted, and T1-weighted images. Main Outcome Measures: Regional cortical atrophy was rated vs controls. Cor tical and juxtacortical lesions were ovoid hyperintensities involving the c ortex and/or gray-white junction. Results: A total of 810 cortical and juxtacortical lesions were seen by FLA IR in patients (mean, 9.6 perpatient), most. commonly ill the superior fron tal lobe. Cortical and juxtacortical lesions were identified in 72 patients and 6 controls. Fourteen percent of cortical and juxtacortical lesions wer e seen on T1-weighted images and 26% were seen on T2-weighted images. More cortical and juxtacortical lesions were present in secondary progressive di sease than relapsing-remitting disease. The total number of cortical and ju xtacortical lesions correlated significantly with disease duration and the regional number correlated with the degree of regional atrophy. After takin g into account noncortical (white matter) lesions, only the cortical and ju xtacortical lesion count predicted atrophy in that region. Conclusions: FLAIR can detect many cortical and juxtacortical lesions in MS , which were appreciated previously in autopsy studies but usually missed b y magnetic resonance imaging during life. Cortical and juxtacortical plaque formation may contribute to cortical atrophy in MS.