Asperger Syndrome: A Proton Magnetic Resonance Spectroscopy Study of the Brain

G. Declan and Murphy et al., Archives of General Psychiatry, October 2002, 59, 885 - 891.

We used in vivo proton magnetic resonance spectroscopy to examine neutronal integrity of the medial prefrontal and parietal lobes in 14 non-learning disabled adults with AS and 18 control subjects (of similar sex, age and IQ). We obtained measures of the prefrontal lobe in 11, the parietal lobe in 13, and both lobes in 10 subjects with AS. We measured concentrations and ratios of N - acetylaspartate (NAA), creatine and phosphocreatine (Cr + PCr), and choline (Cho). Levels of NAA, Cr+ PCr, and Cho are indicators of neuronal density and mitochondrial metabolism, phosphate metabolism, and membrane turnover. Frontal metabolite levels were correlated with scores on the Yale-Brown Obsessive Compulsive Scale and the Autism Diagnostic Interview. Subjects with AS had significantly higher prefrontal lobe concentration of NAA (x = -3.1; P= .002), Cr + PCr (z= -2.2; P= .03) and Cho (z= -2.9; P= .003). Increased prefrontal NAA concentration was significantly correlated with obsessional behaviour (t = 0.72; P=.02). We found no significant differences in parietal lobe metabolite concentrations. Subjects with AS have abnormalities in neuronal integrity of the prefrontal lobe, which is related to severity of clinical symptoms.