title: Proton magnetic resonance spectroscopy as a probe into the pathophysiology of autism spectrum disorders (ASD): a review.
abstract: Proton magnetic resonance spectroscopy ((1) H-MRS) is a safe, noninvasive way of quantifying in vivo biochemical and metabolite concentration levels in individuals with Autism Spectrum Disorders (ASD). Findings to date suggest ASD is associated with widespread reduction in N-acetylaspartate (NAA), creatine plus phosphocreatine (Cr), choline-containing compounds (Cho), myo-inositol (mI), and glutamate plus glutamine plus gamma-Aminobutyric Acid (Glx); however, variable findings, and even substantial increases, are not uncommon depending on the study and/or region-of-interest. Widespread reduction of NAA, Cr, Cho, mI, and Glx in ASD likely reflects impaired neuronal function and/or metabolism related to abnormal neurodevelopmental processes. Future studies should attempt to relate (1) H-MRS findings to histological findings and control for variability in subject age and functioning level; this would assist in evaluating the relationship between (1) H-MRS metabolic levels and neuronal and glial cell densities, as well as neurodevelopmental process associated with ASD. Furthermore, more longitudinal (1) H-MRS studies are needed in both control and ASD subjects to attempt to standardize metabolite levels across different developmental periods in well-defined endophenotypes. This will provide for a standard rubric for which metabolic aberrations (as well as treatment responses) can be measured. With higher magnetic field strengths and spectral-editing techniques capable of quantifying less-concentrated metabolites, (1) H-MRS will continue to be an important tool in ASD research.
authors: Department of Psychiatry and Psychology, Mayo Clinic, Rochester, Minnesota 55905, USA. jmbaru01@louisville.edu
authors: Joshua M
authors: JM
authors: Baruth
authors: Christopher A
authors: CA
authors: Wall
authors: Marc C
authors: MC
authors: Patterson
authors: John D
authors: JD
authors: Port
mesh_terms: D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D001921:Brain / Q000378:metabolism*; D002659:Child Development Disorders, Pervasive / Q000378:metabolism*; D002794:Choline / Q000378:metabolism; D003401:Creatine / Q000378:metabolism; D018698:Glutamic Acid / Q000378:metabolism; D005973:Glutamine / Q000378:metabolism; D006801:Humans; D007294:Inositol / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
chemical_list: D005973:Glutamine; D001224:Aspartic Acid; D018698:Glutamic Acid; D007294:Inositol; D005680:gamma-Aminobutyric Acid; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline
keywords: Autism Spectrum Disorders; N-acetylaspartate; glutamate; myo-inositol; proton magnetic resonance spectroscopy