Unilateral ventricular reflux and asymmetric ventricular distribution of intrathecally introduced contrast medium or tracer.

Fourteen cases of totally or predominantly unilateral ventricular reflux and stasis of intrathecally injected radioisotope or contrast medium were demonstrated by scintigraphy or computed tomographic cisternography. All showed asymmetric enlargement of the lateral ventricles and nine had ipsilateral brain lesions. Four case reports are presented. The pathophysiologic mechanism of communicating hydrocephalus and possible causes of unilateral ventricular reflux are discussed, as well as indications for ventricular shunt installation.