title: Magnetic resonance spectroscopy of normal appearing white matter in early relapsing-remitting multiple sclerosis: correlations between disability and spectroscopy.
abstract: BACKGROUND
  What currently appears to be irreversible axonal loss in normal appearing white matter, measured by proton magnetic resonance spectroscopy is of great interest in the study of Multiple Sclerosis. Our aim is to determine the axonal damage in normal appearing white matter measured by magnetic resonance spectroscopy and to correlate this with the functional disability measured by Multiple Sclerosis Functional Composite scale, Neurological Rating Scale, Ambulation Index scale, and Expanded Disability Scale Score.
  
  
  METHODS
  Thirty one patients (9 male and 22 female) with relapsing remitting Multiple Sclerosis and a Kurtzke Expanded Disability Scale Score of 0-5.5 were recruited from four hospitals in Andalusia, Spain and included in the study. Magnetic resonance spectroscopy scans and neurological disability assessments were performed the same day.
  
  
  RESULTS
  A statistically significant correlation was found (r = -0.38 p < 0.05) between disability (measured by Expanded Disability Scale Score) and N-Acetyl Aspartate (NAA/Cr ratio) levels in normal appearing white matter in these patients. No correlation was found between the NAA/Cr ratio and disability measured by any of the other disability assessment scales.
  
  
  CONCLUSIONS
  There is correlation between disability (measured by Expanded Disability Scale Score) and the NAA/Cr ratio in normal appearing white matter. The lack of correlation between the NAA/Cr ratio and the Multiple Sclerosis Functional Composite score indicates that the Multiple Sclerosis Functional Composite is not able to measure irreversible disability and would be more useful as a marker in stages where axonal damage is not a predominant factor.
authors.affiliation: Unidad de Esclerosis Múltiple, Hospital Universitario Virgen Macarena, Avda, Dr, Fedriani 3, 41003 Sevilla, España. jlruizpe@hotmail.com
authors.forename: Juan Luis
authors.initials: JL
authors.lastname: Ruiz-Peña
authors.forename: Pilar
authors.initials: P
authors.lastname: Piñero
authors.forename: Guillermo
authors.initials: G
authors.lastname: Sellers
authors.forename: Joaquín
authors.initials: J
authors.lastname: Argente
authors.forename: Alfredo
authors.initials: A
authors.lastname: Casado
authors.forename: Jesus
authors.initials: J
authors.lastname: Foronda
authors.forename: Antonio
authors.initials: A
authors.lastname: Uclés
authors.forename: Guillermo
authors.initials: G
authors.lastname: Izquierdo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000032:analysis / Q000378:metabolism; D001369:Axons / Q000378:metabolism / Q000473:pathology*; D015415:Biomarkers / Q000032:analysis; D001921:Brain / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology; D003401:Creatine / Q000032:analysis / Q000378:metabolism; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000175:diagnosis* / Q000503:physiopathology; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012008:Recurrence; D012016:Reference Values; D015203:Reproducibility of Results; D012720:Severity of Illness Index
chemical_list: D015415:Biomarkers; D001224:Aspartic Acid; C000179:N-acetylaspartate; D003401:Creatine