[Magnetic resonance tomography and localized proton spectroscopy in 2 siblings with Canavan's disease]

We present the findings of magnetic resonance imaging (MRI) and localised 1H magnetic resonance spectroscopy (MRS) in two brothers with Canavan's disease, a rare autosomal recessive leukodystrophy. Urine specimens of one child were evaluated by MRS. All examinations were performed in the same whole body 1.5 T superconducting magnet. MRI revealed the typical pattern of leukodystrophy including a more severe demyelination in the older child. The younger brother showed additional high signal lesions in the globi pallidi on T2-weighted images. MRS of the brain had an elevated ratio of N-acetyl-aspartate (NAA)/phosphocreatin + creatin (Cr) while the ratio of Cholin/Cr was reduced. in urine spectroscopy the concentration of NAA was markedly increased. The ratio of NAA/creatin + creatinin was 880 +/- 10% mmol/mol (normal: 5-21 mmol/mol). Diagnosis of Canavan's disease was supported by gas chromatographic urine examination with an 80-100 fold elevation of NAA concentration. Hence, the diagnosis of Canavan's disease could be established by increased ratio of NAA/Cr and decreased ratio of Cho/Cr relation in brain spectroscopy and high NAA concentration in urine spectroscopy.