Atypical X-linked adrenoleukodystrophy: new MRI observations with FLAIR, magnetization transfer contrast, diffusion MRI, and proton spectroscopy.

An 11-year-old boy with an atypical form of X-linked adrenoleukodystrophy is reported predominantly involving the frontal lobes, and later spreading to temporal lobes. Magnetization transfer contrast T1-weighted, and FLAIR images without intravenous paramagnetic contrast medium, clearly identified the leading edge of a central necrotic zone, as well as a splenial lesion. Zonal differences were identified on ADC maps of an echo-planar diffusion MRI sequence that the ADC value of central zone (2.06 x 10(-3) mm(2)/sec) was higher than that of the peripheral zone (1.67 x 10(-3) mm(2)/sec). On proton spectroscopy, besides changes in the peaks of NAA, choline, and myoinositol, prominent peaks between 0.9 and 1.4 ppm were shown belonging to macromolecules, probably to very long chain fatty acids, a diagnostic feature of adrenoleukodystrophy. In addition, a distinct and prominent glycine peak was observed at 3.50 ppm, reflecting excitotoxic brain damage.