title: No MRI evidence of cortical lesions in neuromyelitis optica.
abstract: BACKGROUND
  Neuromyelitis optica (NMO) is a severe inflammatory demyelinating disease of the CNS in which a pathogenic role of anti-aquaporin-4 (AQP4) antibodies has been suggested. Although AQP4 is expressed in human cortex, recent histologic studies have failed to find any evidence of cortical demyelination in NMO.
  
  
  OBJECTIVE
  To evaluate, in vivo, the occurrence of focal and diffuse cortical pathology in NMO.
  
  
  METHODS
  We studied 30 patients with NMO, 30 patients with relapsing-remitting multiple sclerosis (RRMS), and 30 normal controls (NC). RRMS and NC were age- and gender-matched to NMO. The presence of cortical lesions (CLs) was evaluated on double inversion recovery sequence and cortical thickness (CTh) by the application of Freesurfer on 3 volumetric fast field echo T1-weighted images.
  
  
  RESULTS
  No CL was observed in NC or in NMO, while 83 CLs were identified in 20/30 (66.7%) patients with RRMS. Although NMO did not differ from NC in the global CTh, a mild thinning was observed in some cortical areas (postcentral [p = 0.018], precentral [p = 0.009], and calcarine [p = 0.015] gyri) and in the thalamus (p = 0.036). Global and regional cortical thickness was significantly decreased in RRMS compared to both NMO and NC.
  
  
  CONCLUSIONS
  Our in vivo data further suggest that the immune-mediated pathologic process occurring in NMO spares most of the cortex. NMO differs from multiple sclerosis, where CLs and atrophy are frequently found, even in early disease phases. Thus, MRI analysis of the cortex may be a potential diagnostic tool, especially in ambiguous cases.
authors.affiliation: Advanced Neuroimaging Lab of The Multiple Sclerosis Centre of Veneto Region-First Neurology Clinic, Department of Neurosciences, University Hospital of Padua, Italy. calabresem@hotmail.it
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Calabrese
authors.forename: Mi Sun
authors.initials: MS
authors.lastname: Oh
authors.forename: Alice
authors.initials: A
authors.lastname: Favaretto
authors.forename: Francesca
authors.initials: F
authors.lastname: Rinaldi
authors.forename: Valentina
authors.initials: V
authors.lastname: Poretto
authors.forename: Sara
authors.initials: S
authors.lastname: Alessio
authors.forename: Byung-Chul
authors.initials: BC
authors.lastname: Lee
authors.forename: Kyung-Ho
authors.initials: KH
authors.lastname: Yu
authors.forename: Hyeo-Il
authors.initials: HI
authors.lastname: Ma
authors.forename: Paola
authors.initials: P
authors.lastname: Perini
authors.forename: Paolo
authors.initials: P
authors.lastname: Gallo
mesh_terms: D000328:Adult; D051401:Aquaporin 4 / Q000235:genetics; D002540:Cerebral Cortex / Q000473:pathology*; D003711:Demyelinating Diseases / Q000473:pathology; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000473:pathology; D009471:Neuromyelitis Optica / Q000235:genetics / Q000473:pathology*; D011379:Prognosis; D013116:Spinal Cord / Q000473:pathology
chemical_list: D051401:Aquaporin 4