LOCALIZED PROTON MAGNETIC-RESONANCE SPECTROSCOPY OF A CEREBELLAR TUMOR IN A 2-YEAR-OLD CHILD

Noninvasive localized proton magnetic resonance spectroscopy (MRS) was used for differential diagnosis of a focal brain lesion in a 2.5-year -old girl. The clinical signs were a mild head tilt and neck pain. Mag netic resonance imaging (MRI) revealed a lesion in the right hemispher e of the cerebellum, but its nature remained obscure. In this lesion q uantitative determinations of cerebral metabolites by fully relaxed, s hort-echo-time proton MRS revealed markedly lowered N-acetylaspartate (NAA) and pronounced elevations of choline-containing compounds (Cho) and myo-inositol (Ins), whereas metabolite concentrations in cortical gray matter and white matter were within normal ranges. The metabolite pattern of the lesion indicated loss of vital neuroaxonal tissue (low NAA) and enhanced glial proliferation (high Cho and Ins), which, toge ther with the MRT morphology, suggested a brain tumor. The diagnosis w as established by neurosurgical exploration and total extirpation of t he tumor. Histology confirmed an astrocytoma (WHO II). After 2 weeks' recovery the child was discharged with no neurological signs.