title: White matter volume is decreased in the brain of patients with neuromyelitis optica.
abstract: BACKGROUND
  Neuromyelitis optica (NMO) is an inflammatory disease involving predominantly the spinal cord and optic nerves. Whether patients with NMO have a loss in white or grey matter (GM) volumes remains to be determined.
  
  
  METHODS
  Thirty patients with NMO, 30 healthy subjects matched for age and gender, 21 patients with multiple sclerosis (MS) and 20 patients with a clinically isolated syndrome (CIS) were studied. We applied a SIENAX post-treatment software. We compared white matter (WM) and GM volumes between groups and explored correlations of changes in NMO patients with age, gender, duration, disease severity, visual acuity and T2 hyperintensities. We also performed a voxel-based morphometry (VBM) analysis to identify the regions affected by loss of volume.
  
  
  RESULTS
  White matter volume was significantly reduced in patients with NMO (764.4 ± 58.3 cm(3) ) compared to healthy subjects (843.1 ± 49.3 cm(3) ) (P < 0.001), whereas no difference was observed for the GM. Patients with CIS also presented an elective atrophy of WM and MS an atrophy of both WM and GM. We did not find any predictive factors of brain atrophy. The decrease in WM volume in NMO was noted even in the absence of visible MRI hypersignals. The VBM analysis found a few regions of WM atrophy (corpus callosum and optic radiations, P < 0.005, uncorrected) and a few regions of GM atrophy (thalamus and prefrontal cortex, P < 0.001, uncorrected).
  
  
  CONCLUSIONS
  These results suggest a significant brain involvement in NMO, especially an involvement of WM which appears not to be limited to secondary degeneration after spinal cord and optic nerve damage.
authors.affiliation: Département de Neurologie, Hôpitaux Universitaires de Strasbourg, Strasbourg, France. jean-baptiste.chanson@chru-strasbourg.fr
authors.forename: J-B
authors.initials: JB
authors.lastname: Chanson
authors.forename: J
authors.initials: J
authors.lastname: Lamy
authors.forename: F
authors.initials: F
authors.lastname: Rousseau
authors.forename: F
authors.initials: F
authors.lastname: Blanc
authors.forename: N
authors.initials: N
authors.lastname: Collongues
authors.forename: M
authors.initials: M
authors.lastname: Fleury
authors.forename: J-P
authors.initials: JP
authors.lastname: Armspach
authors.forename: S
authors.initials: S
authors.lastname: Kremer
authors.forename: J
authors.initials: J
authors.lastname: de Seze
mesh_terms: D000328:Adult; D001284:Atrophy / Q000473:pathology; D001921:Brain / Q000473:pathology* / Q000503:physiopathology; D016022:Case-Control Studies; D003711:Demyelinating Diseases / Q000473:pathology / Q000503:physiopathology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000473:pathology / Q000503:physiopathology; D009413:Nerve Fibers, Myelinated / Q000473:pathology* / Q000502:physiology; D036421:Nerve Fibers, Unmyelinated / Q000473:pathology / Q000502:physiology; D059906:Neuroimaging; D009471:Neuromyelitis Optica / Q000473:pathology* / Q000503:physiopathology; D014792:Visual Acuity / Q000502:physiology