MRI appearances of metachromatic leukodystrophy

Background. The leukodystrophies constitute a wide spectrum of cerebral dis orders of varying etiology. The imaging appearances on CT and MRI are recog nizable 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 symptomato logy diagnosed with metachromatic leukodystrophy (MLD) had remarkably simil ar MRI appearances. A "tigroid" or "leopard-skin" appearance was demonstrat ed 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 no w be considered when these MRI appearances are encountered.