In vivo study of brain metabolism in galactosemia by 1H and 31P magnetic resonance spectroscopy.

In order to further evaluate different hypotheses concerning brain metabolism in galactosemia, six adult patients aged 18-29 years with classical galactosemia under dietary treatment underwent localized 1H and 31P magnetic resonance spectroscopy (MRS) in addition to conventional T1- and T2-weighted MRI. Galactose-1-phosphate levels in erythrocytes were 1.1-3.7 mg/dl, plasma concentrations of galactitol ranged from 8.4-14.2 mumol/l. Imaging revealed abnormal peripheral myelination in five and enlargement of lateral ventricles in two patients. Brain galactitol in parieto-occipital white matter was below detectability of 1H MRS leading to the assumption that brain concentrations of the free metabolite was well below 1 mmol/kg. Signal intensities of free myo-inositol, which was postulated to be indicative of changes in the second messenger pathway, were within the normal range. MRS data revealed a normal energy status of the brain. In summary 1H and 31P MRS indicated normal metabolite concentrations as compared to healthy controls.