title: White matter spectroscopy in neuromyelitis optica: a case control study.
abstract: BACKGROUND
  Naa/Cr ratio in normal appearing white matter (NAWM) of patients with multiple sclerosis (MS) is altered beyond plaques, suggesting early axonal loss, and correlates to clinical disability. Brain lesions not typical of MS have been described in Neuromyelitis optica (NMO), and correspond to brain aquaporin-4 channel sites, but the evaluation of Naa/Cr ratio in NAWM of patients with NMO and its association to the presence of brain lesions and clinical disability have not been described.
  
  
  OBJECTIVE
  To evaluate the Naa/Cr of normal appearing white matter (NAWM) in 16 patients with NMO compared to healthy controls.
  
  
  METHODS
  We performed brain magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) of 16 patients with NMO and compared to age matched healthy controls.
  
  
  RESULTS
  NAWM Naa/Cr did not show statistical difference among patients and controls, neither between patients that had normal brain MRI and atypical brain lesions.
  
  
  CONCLUSIONS
  NAWM was found to have a normal Naa/Cr in patients with NMO, reinforcing the concept that the white matter is not primarily affected in this disease.
authors.affiliation: Dept. of Neurology and Neurosurgery, Federal University of São Paulo (UNIFESP), Rua Pedro de Toledo 377, São Paulo, SP, Brazil.
authors.forename: Denis Bernardi
authors.initials: DB
authors.lastname: Bichuetti
authors.forename: René Leandro Magalhães
authors.initials: RL
authors.lastname: Rivero
authors.forename: Enedina Maria Lobato
authors.initials: EM
authors.lastname: de Oliveira
authors.forename: Daniel May
authors.initials: DM
authors.lastname: Oliveira
authors.forename: Nilton Amorin
authors.initials: NA
authors.lastname: de Souza
authors.forename: Roberto Gomes
authors.initials: RG
authors.lastname: Nogueira
authors.forename: Nitamar
authors.initials: N
authors.lastname: Abdala
authors.forename: Alberto
authors.initials: A
authors.lastname: Gabbai
mesh_terms: D000328:Adult; D001921:Brain / Q000473:pathology; D016022:Case-Control Studies; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008875:Middle Aged; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D009471:Neuromyelitis Optica / Q000175:diagnosis* / Q000473:pathology; D011446:Prospective Studies; D055815:Young Adult