Structural abnormalities of the brain other than molar tooth sign in Joubert syndrome-related disorders

PURPOSE: We performed a retrospective study in which we investigated malformations other than brainstem and vermian dysgenesis in Joubert syndrome-related disorders (JSRD). We investigated the frequency and type of structural abnormalities that coexist with the molar tooth sign (MTS) in JSRD. MATERIALS AND METHODS: We searched our archive for the years 2002-2008 in order to find patients with the diagnosis of JSRD. Cranial magnetic resonance imaging studies of 20 patients with the diagnosis of JSRD were reviewed by two neuroradiologists. RESULTS: In addition to known anomalies including callosal dysgenesis, heterotopia, polymicrogyria, atretic encephalocele, hypomyelination, and nonobstructive dilatation of lateral ventricles; malformations that have not been previously reported were determined, including cerebellar folial disorganization, hippocampal malformation, temporal lob hypoplasia, ambient cistern lipoma, and parenchymal cyst. CONCLUSION: Structural abnormalities associated with the MTS are not rare, and the additional imaging findings may help explain the neurological presentation in these patients.