Proton MR spectroscopy and neuropsychological testing in adrenoleukodystrophy

PURPOSE: To determine early signs of disease in patients with childhood- onset cerebral adrenoleukodystrophy (COCALD) with the use of proton MR spectroscopy. METHODS: Eleven children with posterior COCALD involvement and three children with anterior COCALD involvement were studied with single- voxel proton MR spectroscopy and neuropsychological testing. Findings were compared with those in five healthy control subjects. RESULTS: Areas of abnormal T2 signal intensity in children with COCALD showed abnormal metabolite ratios relative to those of control subjects as follows: decreased N-acetylaspartate (NAA)/Creatine (Cr) and NAA/Choline (Ch) and increased Ch/Cr. Metabolite ratios from normal-appearing brain regions in the same patients also were abnormal, with reduced NAA/Cr and NAA/Ch and increased Ch/Cr values. The mean metabolite ratios in normal-appearing regions were between those in the abnormal regions and those found in the control subjects. Statistical comparison of these ratios with neuropsychological test scores, which are specific for anterior and posterior brain functions, showed a significant correlation with the abnormal metabolite ratios. Our results indicate that the normal-appearing brain regions in these patients are metabolically abnormal. CONCLUSION: Proton MR spectroscopy could be a useful noninvasive tool to evaluate extent of disease in patients with COCALD.