In vivo 1H-magnetic resonance spectroscopy study of amygdala-hippocampal and parietal regions in autism.

Abstract

The neural basis for autistic spectrum disorders is unclear, but abnormalities in the development of limbic areas and of glutamate have been suggested. Proton magnetic resonance spectroscopy ((1)H-MRS) can be used to measure the concentration of brain metabolites. However, the concentration of glutamate/glutamine in brain regions implicated in autistic spectrum disorders has not yet been examined in vivo. The authors used (1)H-MRS to investigate the neuronal integrity of the amygdala-hippocampal complex and a parietal control region in adults with autistic spectrum disorders and healthy subjects. People with autistic spectrum disorders had a significantly higher concentration of glutamate/glutamine and creatine/phosphocreatine in the amygdala-hippocampal region but not in the parietal region. Abnormalities in glutamate/glutamine may partially underpin the pathophysiology of autistic spectrum disorders, and the authors confirm earlier reports that limbic areas are metabolically aberrant in these disorders.