Globoid cell leukodystrophy: distinguishing early-onset from late-onset disease using a brain MR imaging scoring method.

BACKGROUND AND
PURPOSE: Our purpose was to determine the characteristic MR features of early-onset (before age 2 years) versus late-onset (after age 2 years) globoid cell leukodystrophy (GLD).
METHODS: Thirty-four brain MR images in 22 patients with GLD were reviewed. A severity score (0 to 32), based on a point system derived from the location and extent of disease and the presence of focal and/or global atrophy, was calculated for each examination.
RESULTS: Of the 22 patients, three were asymptomatic and 19 were symptomatic. Ten patients had early-onset disease, whereas nine had late-onset disease. MR images of all patients showed abnormalities. In the early-onset group (n = 10; mean maximum MR score, 8.1; range, 3-18), 90% had pyramidal tract involvement, 80% had cerebellar white matter involvement, 70% had deep gray matter involvement, 60% had posterior corpus callosal involvement, 50% had parietooccipital white matter involvement, and 40% had cerebral atrophy. Serial MR imaging in four of these patients revealed progressive disease. In the late-onset group (n = 9; mean maximum MR score, 5.6; range, 4-10), 100% had pyramidal tract involvement, 100% had parietooccipital white matter involvement, 89% had posterior corpus callosal involvement, and none had cerebellar white matter involvement, deep gray matter involvement, or cerebral atrophy. Serial MR imaging in one patient with late-onset GLD did not reveal any change. A spectrum of findings was observed in the three patients who were asymptomatic.
CONCLUSION: Cerebellar white matter and deep gray matter involvement are present only in early-onset GLD. Pyramidal tract involvement is a characteristic finding in both early- and late-onset GLD. This scoring method for brain MR observations will assist in the objective assessment of the impact of hematopoietic stem cell transplantation in patients with GLD.