Alterations of brain metabolites in metachromatic leukodystrophy as detected by localized proton magnetic resonance spectroscopy in vivo.

The brain morphology and chemistry of seven children with late infantile (4/7) and juvenile (3/7) forms of metachromatic leukodystrophy (MLD) were investigated by magnetic resonance imaging (MRI) and localized proton magnetic resonance spectroscopy (MRS). Patients who were examined at least 6 months after the onset of symptoms (6/7) had severe leukodystrophic changes on MRI. Proton MRS revealed a marked reduction of the neuronal marker N-acetylaspartate in white and grey matter and elevated lactate in demyelinated areas. In contrast to other leukodystrophies MLD patients showed a generalized increase of brain myo-inositol (2- to 3-fold in white matter), indicating a specific role in the pathophysiology of demyelination in MLD.