title: Cortical N-acetyl aspartate is a predictor of long-term clinical disability in multiple sclerosis.
abstract: OBJECTIVE
  To evaluate the prognostic value of the cortical N-acetyl aspartate to creatine ratio (NAA/Cr) in early relapsing-remitting multiple sclerosis (RRMS).
  
  
  METHODS
  Sixteen patients with newly diagnosed RRMS were studied by serial MRI and MR spectroscopic imaging (MRSI) once every 6 months for 24 months. Clinical examinations, including the expanded disability status scale (EDSS), were performed at baseline, month 24, and at year 7.
  
  
  RESULTS
  Baseline cortical NAA/Cr correlated inversely with EDSS at month 24 (r  =  -0·61, P < 0·05), and patients with EDSS ≧ 4 had a lower baseline cortical NAA/Cr compared to those with EDSS less than 4 (P < 0·05). Baseline cortical NAA/Cr also correlated inversely with EDSS at the 7-year follow-up (r  =  -0·56, P < 0·05), and patients with EDSS ≧ 4 had a lower baseline cortical NAA/Cr compared to those with EDSS less than 4 (P < 0·05). Baseline brain parenchymal fraction (BPF) correlated inversely with EDSS at month 24 (r  =  -0·61, P < 0·05), but not with EDSS at year 7.
  
  
  CONCLUSIONS
  Cortical NAA/Cr in early RRMS correlated with clinical disability after 2 and 7 years and may be used as a predictor of long-term disease outcome.
authors.forename: Xingchen
authors.initials: X
authors.lastname: Wu
authors.forename: Lars Grüner
authors.initials: LG
authors.lastname: Hanson
authors.forename: Arnold
authors.initials: A
authors.lastname: Skimminge
authors.forename: Per Soelberg
authors.initials: PS
authors.lastname: Sorensen
authors.forename: Olaf Bjarne
authors.initials: OB
authors.lastname: Paulson
authors.forename: Henrik Kahr
authors.initials: HK
authors.lastname: Mathiesen
authors.forename: Morten
authors.initials: M
authors.lastname: Blinkenberg
mesh_terms: D000328:Adult; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D002540:Cerebral Cortex / Q000378:metabolism* / Q000473:pathology; D003401:Creatine / Q000378:metabolism; D004185:Disability Evaluation; D018450:Disease Progression; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000175:diagnosis* / Q000378:metabolism; D011379:Prognosis; D055815:Young Adult
chemical_list: D001224:Aspartic Acid; C000179:N-acetylaspartate; D003401:Creatine
keywords: Cortical NAA,; Cortical choline,; MRI,; MRSI,; Multiple sclerosis