Low levels of N-acetyl aspartate in the left dorsolateral prefrontal cortex of pediatric bipolar patients.
BACKGROUND
Increasing 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 ((1)H 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.


METHODS
We 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 (1)H spectroscopy approach point-resolved spectroscopy (PRESS) sequence, measurements of metabolites was performed on a 1.5T Philips MR system.


RESULTS
BP 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 (PCr+Cr), 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.
Olvera
Rene L
RL
Division of Child and Adolescent Psychiatry, Department of Psychiatry, The University of Texas Health Science Center at San Antonio, San Antonio, Texas.
Caetano
Sheila C
SC
Fonseca
Manoela
M
Nicoletti
Mark
M
Stanley
Jeffrey A
JA
Chen
Hua Hsuan
HH
Hatch
John P
JP
Hunter
Kristina
K
Pliszka
Steven R
SR
Soares
Jair C
JC
D000293:Adolescent; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000032:analysis / Q000378:metabolism; D001714:Bipolar Disorder / Q000378:metabolism / Q000503:physiopathology*; D002648:Child; D003401:Creatine / Q000378:metabolism; D005260:Female; D005997:Glycerylphosphorylcholine / Q000378:metabolism; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male; D010725:Phosphocreatine / Q000378:metabolism; D010767:Phosphorylcholine / Q000378:metabolism; D017397:Prefrontal Cortex / Q000737:chemistry* / Q000503:physiopathology*; D011627:Puberty