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3 dimensional view of N-acetyl-L-aspartate |
N-acetylaspartate,
or NAA, is the second most abundant metabolite in the human central
nervous system (CNS). The functional significance of the high NAA
concentration in the brain remains uncertain, but it confers on NAA a
unique clinical significance due to the fact that NAA emits the
strongest signal in magnetic resonance spectrograms of the human brain.
NAA levels measured by magnetic resonance spectroscopy are changed in a
wide array of CNS disorders, but it is unknown if the changes are
etiological, or merely secondary. Magnetic resonance studies of human
brain disorders have invariably detected decreases in brain NAA
concentrations when neuronal loss of dysfunction are involved, with one
major exception. The autosomal genetic
disease, Canavan disease, involves the accumulation of NAA in the brain
due to the lack of degradative enzyme activity. Virtually all other
neurological disorders involving neuronal loss or dysfunction result in
reductions in brain NAA levels including Alzheimer disease, epilepsy,
amyotrophic lateral sclerosis,
schizophrenia, multiple sclerosis,
AIDS, traumatic brain injury, stroke and non-neuronal brain tumors such
as glioma.
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