MRI appearances of metachromatic leukodystrophy.

BACKGROUND: The leukodystrophies constitute a wide spectrum of cerebral disorders of varying etiology. The imaging appearances on CT and MRI are recognizable as abnormalities of white matter; however, it may be impossible to arrive at the correct diagnosis based on imaging studies alone.

PATIENTS AND METHODS: Three patients of varying age and clinical symptomatology diagnosed with metachromatic leukodystrophy (MLD) had remarkably similar MRI appearances. A "tigroid" or "leopard-skin" appearance was demonstrated within deep white matter in each case.

RESULTS: All of the patients had biochemical confirmation of MLD.

CONCLUSION: Although the "tigroid" pattern previously was considered to be pathognomonic of Pelizaeus-Merzbacher disease, the diagnosis of MLD must now be considered when these MRI appearances are encountered.