title: Identification and clinical impact of multiple sclerosis cortical lesions as assessed by routine 3T MR imaging.
abstract: OBJECTIVE
  Histopathologic studies have reported widespread cortical lesions in MS; however, in vivo detection by using routinely available pulse sequences is challenging. We investigated the relative frequency and subtypes of cortical lesions and their relationships to white matter lesions and cognitive and physical disability.
  
  
  METHODS
  Cortical lesions were identified and classified on the basis of concurrent review of 3D FLAIR and 3D T1-weighted IR-SPGR 3T MR images in 26 patients with MS. Twenty-five patients completed the MACFIMS battery. White matter lesion volume, cortical lesion number, and cortical lesion volume were assessed.
  
  
  RESULTS
  Overall, 249 cortical lesions were detected. Cortical lesions were present in 24/26 patients (92.3%) (range per patient, 0-30; mean, 9.6 ± 8.8). Most (94.4%, n = 235) cortical lesions were classified as mixed cortical-subcortical (type I); the remaining 5.6% (n = 14) were classified as purely intracortical (type II). Subpial cortical lesions (type III) were not detected. White matter lesion volume correlated with cortical lesion number and cortical lesion volume (r(S) = 0.652, r(S) = 0.705, respectively; both P < .001). After controlling for age, depression, and premorbid intelligence, we found that all MR imaging variables (cortical lesion number, cortical lesion volume, white matter lesion volume) correlated with the SDMT score (R(2) = 0.513, R(2) = 0.449, R(2) = 0.418, respectively; P < .014); cortical lesion number also correlated with the CVLT-II scores (R(2) = 0.542-0.461, P < .043). The EDSS scores correlated with cortical lesion number and cortical lesion volume (r(S) = 0.472, r(S) = 0.404, respectively; P < .05), but not with white matter lesion volume.
  
  
  CONCLUSIONS
  Our routinely available imaging method detected many cortical lesions in patients with MS and was useful in their precise topographic characterization in the context of the gray matter-white matter junction. Routinely detectable cortical lesions were related to physical disability and cognitive impairment.
authors.affiliation: Center for Neurological Imaging, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA.
authors.forename: A
authors.initials: A
authors.lastname: Mike
authors.forename: B I
authors.initials: BI
authors.lastname: Glanz
authors.forename: P
authors.initials: P
authors.lastname: Hildenbrand
authors.forename: D
authors.initials: D
authors.lastname: Meier
authors.forename: K
authors.initials: K
authors.lastname: Bolden
authors.forename: M
authors.initials: M
authors.lastname: Liguori
authors.forename: E
authors.initials: E
authors.lastname: Dell'Oglio
authors.forename: B C
authors.initials: BC
authors.lastname: Healy
authors.forename: R
authors.initials: R
authors.lastname: Bakshi
authors.forename: C R G
authors.initials: CR
authors.lastname: Guttmann
mesh_terms: D000328:Adult; D001921:Brain / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009103:Multiple Sclerosis / Q000473:pathology*; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity