A proton spectroscopy study of white matter in children with autism

Abstract

White matter abnormalities have been described in autism spectrum disorder (ASD) with mounting evidence implicating these alterations in the pathophysiology of the aberrant connectivity reported in this disorder. The goal of this investigation is to further examine white matter structure in ASD using proton magnetic resonance spectroscopy ((1)H MRS). Multi-voxel, short echo-time in vivo(1)H MRS data were collected from 17 male children with ASD and 17 healthy age- and gender-matched controls. Key (1)H MRS metabolite ratios relative to phosphocreatine plus creatine were obtained from four different right and left white matter regions. Significantly lower N-acetylaspartate/creatine ratios were found in the anterior white matter regions of the ASD group when compared to controls. These findings reflect impairment in neuroaxonal white matter tissue and shed light on the neurobiologic underpinnings of white matter abnormalities in ASD by implicating an alteration in myelin and/or axonal development in this disorder.

Keywords: Connectivity; In vivo(1)H MRS; N-acetylaspartate (NAA); Phosphocreatine plus creatine.

Figure 1

White matter voxel localizations and representative quantified ¹H MRS spectra of the 4 right and left brain regions: Region 1 (R1; A and B): anterior frontal white matter regions; Region 2 (R2; C and H): anterior middle centrum semiovale; Region 3 (R3; D and G): posterior middle centrum semiovale; Region 4 (R4; E and F): posterior parietal white matter.