Disproportionately large communicating fourth ventricle with syringomyelia: case report.

A 13-year-old boy presented with syringomyelia associated with disproportionately large communicating fourth ventricle (DLCFV) manifesting as symptoms attributable to hydrocephalus and characteristic posterior fossa symptoms. Magnetic resonance imaging demonstrated remarkable dilation of the fourth ventricle and syringomyelia. Ventriculoperitoneal shunting completely resolved all symptoms as well as the ventricular and spinal cord abnormalities. Pre- and postoperative cine magnetic resonance imaging revealed the change of cerebrospinal fluid flow signal in the area of the foramen magnum. We concluded that the syringomyelia could be described as enlargement of the central canal with DLCFV.