title: Decreased motor cortex γ-aminobutyric acid in amyotrophic lateral sclerosis.
abstract: OBJECTIVE
  To determine if there are in vivo differences in γ-aminobutyric acid (GABA) in the motor cortex and subcortical white matter of patients with amyotrophic lateral sclerosis (ALS) compared with healthy controls using proton magnetic resonance spectroscopy (1H-MRS).
  
  
  METHODS
  In this cross-sectional study, 10 patients with ALS and 9 age- and sex-matched healthy controls (HCs) underwent 3T edited 1H-MRS to quantify GABA centered on the motor cortex and the subcortical white matter.
  
  
  RESULTS
  Compared with healthy controls, patients with ALS had significantly lower levels of GABA in the left motor cortex (1.42 ± 0.27 arbitrary institutional units vs. 1.70 ± 0.24 arbitrary institutional units, p = 0.038). There was no significant difference in GABA levels between groups in the subcortical white matter (p > 0.05).
  
  
  CONCLUSIONS
  Decreased levels of GABA are present in the motor cortex of patients with ALS compared to HCs. Findings are consistent with prior reports of alterations in GABA receptors in the motor cortex as well as increased cortical excitability in the context of ALS. Larger, longitudinal studies are needed to confirm these findings and to further our understanding of the role of GABA in the pathogenesis of ALS.
authors.affiliation: Department of Radiology, University of Michigan, Ann Arbor, USA. compfun@umich.edu
authors.forename: B R
authors.initials: BR
authors.lastname: Foerster
authors.forename: B C
authors.initials: BC
authors.lastname: Callaghan
authors.forename: M
authors.initials: M
authors.lastname: Petrou
authors.forename: R A E
authors.initials: RA
authors.lastname: Edden
authors.forename: T L
authors.initials: TL
authors.lastname: Chenevert
authors.forename: E L
authors.initials: EL
authors.lastname: Feldman
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000690:Amyotrophic Lateral Sclerosis / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology*; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000000981:diagnostic imaging / Q000378:metabolism*; D011522:Protons; D011877:Radionuclide Imaging; D055815:Young Adult; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
chemical_list: D011522:Protons; D001224:Aspartic Acid; D005680:gamma-Aminobutyric Acid; C000179:N-acetylaspartate