Magnetic resonance imaging of central nervous system defects in Usher's syndrome.

With the use of magnetic resonance imaging, seven patients with type II Usher's syndrome were evaluated for CNS defects. The goals of this study were to confirm the presence of CNS defects previously detected by computed tomography (CT) scans in patients with Usher's syndrome while seeking additional anatomic defects in the posterior fossa employing a potentially more sensitive procedure using magnetic resonance imaging. Findings of CNS lesions in both the midbrain (high-signal-intensity lesions) and the cerebellum (vermian atrophy) necessitate further characterization of these defects in terms of their progressive nature and clinical significance for patients with Usher's syndrome.