Brain metabolite changes on in vivo proton magnetic resonance spectroscopy in children with congenital hypothyroidism.

Localized in vivo proton magnetic resonance spectroscopy and imaging were performed in five children with untreated congenital hypothyroidism to look for biochemical markers of abnormal myelin and neuronal development. The patients had high levels of choline-containing compounds, which returned to normal with euthyroidism. These metabolic alterations may reflect blocks in myelin maturation that are reversible by thyroid hormone replacement throughout childhood.