title: Proton magnetic resonance spectroscopy of the motor cortex in 70 patients with amyotrophic lateral sclerosis.
abstract: OBJECTIVE
  To evaluate proton magnetic resonance spectroscopy for detection and monitoring of upper motoneuron degeneration in patients with amyotrophic lateral sclerosis.
  
  
  METHODS
  Seventy patients with amyotrophic lateral sclerosis according to the El Escorial criteria were compared with 48 healthy control subjects. Single-volume proton magnetic resonance spectroscopy (echo time, 272 milliseconds; repetition time, 2000 milliseconds) was performed in both motor cortices for detection of N-acetylaspartate (NAA), phosphocreatine + creatine ([P]Cr), and choline-containing compounds (Cho) to calculate the metabolite ratios NAA/Cho, NAA/(P)Cr, and Cho/(P)Cr. In addition, absolute metabolite concentrations of NAA, (P)Cr, and Cho were obtained in 30 patients and 15 controls with the unsuppressed water signal used as an internal reference.
  
  
  RESULTS
  Absolute concentrations of NAA (P<.001) and (P)Cr (P<.05) were reduced in motor cortices of patients, whereas Cho concentrations remained unchanged. The NAA/Cho and NAA/(P)Cr ratios were reduced in all El Escorial subgroups (P<.001). The Cho/(P)Cr ratio was elevated in patients with definite amyotrophic lateral sclerosis (P<.05). Metabolite ratio changes corresponded to the lateralization of clinical symptoms and were weakly correlated with disease duration and disease severity. In follow-up observations of 16 patients during a mean (+/-SD) of 12.1 +/- 8.7 months, NAA/Cho dropped by 9.1% (P<.01), and Cho/(P)Cr increased by 7.0% (P<.01). Changes of metabolite ratios were significantly correlated with progression of disease severity.
  
  
  CONCLUSIONS
  Measurement of NAA concentrations and NAA/Cho ratios appear to be most suitable for detection of motor cortex degeneration by single-volume proton magnetic resonance spectroscopy. Reduced NAA/Cho ratios correspond to aspects of the clinical presentation and reflect disease progression in follow-up measurements.
authors.affiliation: Department of Neurology, University of Bonn, Sigmund-Freud-Str 25, D-53105 Bonn, Germany. c.pohl@uni-bonn.de
authors.forename: C
authors.initials: C
authors.lastname: Pohl
authors.forename: W
authors.initials: W
authors.lastname: Block
authors.forename: J
authors.initials: J
authors.lastname: Karitzky
authors.forename: F
authors.initials: F
authors.lastname: Träber
authors.forename: S
authors.initials: S
authors.lastname: Schmidt
authors.forename: C
authors.initials: C
authors.lastname: Grothe
authors.forename: R
authors.initials: R
authors.lastname: Lamerichs
authors.forename: H
authors.initials: H
authors.lastname: Schild
authors.forename: T
authors.initials: T
authors.lastname: Klockgether
mesh_terms: D000328:Adult; D000690:Amyotrophic Lateral Sclerosis / Q000175:diagnosis* / Q000503:physiopathology; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D002794:Choline / Q000378:metabolism; D003401:Creatine / Q000378:metabolism; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000592:standards*; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000378:metabolism / Q000473:pathology*; D010725:Phosphocreatine / Q000378:metabolism; D012016:Reference Values; D012720:Severity of Illness Index
chemical_list: D010725:Phosphocreatine; D001224:Aspartic Acid; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline