Cerebral fluorine-18 fluorodeoxyglucose positron emission tomographic findings in X-linked adrenoleukodystrophy

Fluorine-18 fluorodeoxygluclose (F-18 FDG) scan findings are reported in a 10-year-old boy with X-linked adrenoleukodystrophy (X-ALD) who was evaluated for progressive encephalopathy, which is characteristic of the disease. The brain MRI study showed typical white matter abnormalities in the parietal and occipital lobes. The subsequent F-18 FDG revealed hypometabolic activity in the cerebral cortex, most prominently in the occipital lobes and particularly in the visual cortex. There was evidence of a gradient of diffusely increased glucose metabolism in most of the cerebral white matter. These changes were most prominent in the parietal and temporal lobes and less marked in the occipital areas. The functional changes demonstrated by the F- 18 FDG scan were more extensive than the structural abnormalities demonstrated by MRI and better correlated with the the patient's rapid neurologic deterioration. Brain F-18 FDG positron emission tomographic (PET) imaging is helpful in the accurate delineation of the involved areas and in monitoring the progression of the demyelinating process in the different stages of this disease. The results also suggest that F-18 FDG PET may be useful in detecting demyelinating diseases associated with inflammation.