THE MUCOPOLYSACCHARIDOSES - CHARACTERIZATION BY CRANIAL MR-IMAGING

PURPOSE. To characterize MR findings in mucopolysaccharidoses (MPS), t o aid in diagnosis and categorization, and to define the role of MR in preoperative evaluation. MATERIALS AND METHODS: Six children with Hur ler syndrome (MPS IH), five with Hunter syndrome (MPS II), and three w ith Sanfilippo A syndrome (MPS IIIA)-were studied by routine T1-weight ed and T2-weighted images at 1.5 T. MR findings were graded retrospect ively. RESULTS: All had hallmark cribriform changes (sieve-like or mul ticystic) involving peri- and supraventricular, parietal, white matter (12), corpus callosum (8), and basal ganglia (4), which did not enhan ce. The cerebellum and brain stem were not involved with these cribrif orm changes. The most severe degree of cribriform changes occurred in children with Hunter and Hurler syndromes, correlating with non-centra l nervous system somatic involvement, but inversely related to degree of atrophy, ventricular enlargement, and white matter changes. Mental retardation was most severe in children with Hurler syndrome and corre lated with chronicity of the disease. Severity of mental retardation d id not correlate with severity of cribriform changes. CONCLUSIONS: Bas ed on our observations, we postulate that in the natural course of MPS , cribriform changes occurred first, followed by white-matter changes and, last, atrophy. More severe degrees of cribriform changes plus inv olvement of the corpus callosum may suggest a poorer prognosis. Optima l therapeutic intervention may be at the time of cribriform changes be fore atrophy has occurred. MR can define and grade these changes.