Proton MR spectroscopy correlates of frontal lobe function in healthy children.
OBJECTIVE
Neuroimaging methods have been used to improve our understanding of the topographic organization of the brain. In our study, proton (1)H-MR spectroscopic imaging was used to evaluate frontal lobe function. The goal was to determine the relationship between neuropsychological measures of frontal lobe function and levels of a surrogate neuronal marker, N-acetylaspartate (NAA), in typically developing healthy children and adolescents.


METHODS
Fifty-one healthy children (25 girls; 6.2-18.3 years of age; mean age, 12.3 +/- 3.6 years) were examined. All children completed a neuropsychological assessment including measures of attention, executive function, memory, language, and visual and motor skills. (1)H-MR spectroscopic imaging was performed by using a multisection spin-echo sequence at 1.5T. General linear model analysis of covariance was used to examine the relationship between the neuropsychological test scores and NAA/creatine (Cr) ratios, controlling for age and sex.


RESULTS
A positive relationship between frontal lobe white matter NAA/Cr ratio and performance on 2 neuropsychological tests associated with frontal lobe function was detected. The Purdue Pegboard right-hand scores were higher with increasing NAA/Cr in the left frontal white matter (P = .047), and Stanford-Binet-IV "Bead Memory" scores improved with increasing NAA/Cr ratio in the right frontal white matter (P = .032).


CONCLUSIONS
An association between frontal white matter NAA/Cr ratios and 1) measures of manual speed and dexterity, and 2) visual working memory was detected. Our data may provide a quantitative basis for assessment of frontal lobe impairments in disease states.
Russell H Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD 21205, USA.
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Ozturk
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Degaonkar
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Matson
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Wells
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Mahone
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Horská
D000293:Adolescent; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000032:analysis; D002648:Child; D005625:Frontal Lobe / Q000502:physiology*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008570:Memory, Short-Term / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D011522:Protons; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014018:Tissue Distribution
D011522:Protons; D001224:Aspartic Acid; C000179:N-acetylaspartate