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02 28th, 2008| 
Abstract
The objective of this study was to measure myelination of frontal lobe changes in infants and young children. Twenty-four cases of infants and children (age range 12–121 months) were evaluated by a quantitative assessment of T2- weighted MR image features. Reliable quantitative changes between white and gray matter correlated with developmental age in a group of children with no neurological findings. Myelination appears to be an increasing exponential function with the greatest rate of change occurring over the first 3 years of life. The quantitative changes observed were in accordance with revious
qualitative judgments of myelination development. Children with periventricular leukomalacia (PVL) showed delays in achieving levels of myelination when compared to normal children and adjusted for chronological age. The quantitative measure of myelination development may prove to be useful in assessing the stages of development and helpful in the quantitative descriptions of white matter disorders such as PVL.
Introduction
The relations between brain development and behavior in human infants and young children are of interest to developmental psychologists. For example, there are changes in brain development that relate to the acquisition of perceptual and cognitive processes. Also of interest are developmental issues: how are the changes in myelination in the developing brain related to changes in social, emotional, and cognitive domains? Many of the changes in behavior, including social and emotional behavior, have been quantified; therefore, it would be useful to have a quantified measure of brain development to compare to the measures of behavior. A method of assessing developmental brain change is to assess the changing levels of myelination. One approach to assessing myelination is to view the stained samples of brain tissue from specimens. Histologic studies of myelination of the forebrain have found no myelinated fibers before the seventh fetal month. In the telencephalic division of the forebrain, myelinated fibers first appear in the white matter of the cerebral hemispheres in the tenth fetal month. In the supralimbic zone of the forebrain, which comprises the white matter of the cortical layers, the myelination of the subcortical white matter is synchronized with the myelination of cortical projections from the dorsolateral and posterior nuclei of thalamus. Read the rest of this entry »