Low Levels of N-Acetyl Aspartate in the Left Dorsolateral Prefrontal Cortex of Pediatric Bipolar Patients.

BackgroundIncreasing evidence suggests abnormalities in the structure, function, and neurochemistry of the frontal cortex in pediatric bipolar (BP) patients. We conducted a single-voxel proton magnetic resonance spectroscopy (1H MRS) of the left dorsolateral prefrontal cortex (DLPFC) of pediatric BP patients, expecting lower N-acetyl-aspartate (NAA) levels within that brain region compared to healthy comparison subjects.MethodsWe studied 35 pediatric BP (23 BP type I, 12 BP type II; mean age ± SD 13.2 ± 2.9 years; 18 females) and 36 healthy controls (mean age ± SD 13.7 ± 2.6 years, 17 females). A short echo time, single-voxel 1H spectroscopy approach point-resolved spectroscopy (PRESS) sequence, measurements of metabolites was performed on a 1.5T Philips MR system.ResultsBP subjects had significantly lower NAA levels in the left DLPFC compared to healthy controls (F 4.21, df 1, 68, p 0.04). There was not a significant difference between groups for phosphocreatine creatine (PCrCr), glycerolphosphocholine phosphocholine (GPC PC), myo-inositol (mI), or glutamate. Further analyses revealed a significant reduction of NAA in our early puberty group compared to controls (Mann-Whitney U-test statistic 52.00, p 0.014), but not for BP versus controls in other pubertal groups.Conclusions BP subjects have lower NAA levels in the left DLPFC compared to healthy subjects, suggesting neuronal dysfunction in this region. [ABSTRACT FROM AUTHOR]