Rhombencephalosynapsis diagnosed in childhood: clinical and MRI findings.

Rhombencephalosynapsis (RES) is a rare cerebellar malformation of unknown etiology characterized by vermal agenesis or hypogenesis, fusion of hemispheres and the dentate nuclei. Clinical presentation and prognosis are extremely variable and generally depends one the associated supratentorial anomalies. We report the first Tunisian case of RES diagnosed by magnetic resonance imaging (MRI) in a 3.5-year-old boy born to consanguineous parents. The child had spastic diplegia, facial dysmorphia, skeletal anomalies and normal intellectual development. Additional supratentorial anomalies were agenesis of septum pellucidum, moderate hydrocephalus and hypogenesis of corpus callosum. In this paper, the clinical and MRI findings and possible pathogenesis of this disorder are discussed.