"Glutamate-Glutamine (Glx) peak is one of the regions assessed on MR spectroscopy, and resonates between 2.2 and 2.4 ppm chemical shift. It overlaps with the GABA peak and cannot be routinely separated from each other. The concentration of these two brain metabolites increases in hepatic and hypoxic encephalopathy and in the very rare Reye syndrome 3-8."