DIVERTICULA OF THE LATERAL VENTRICLES EXTENDING INTO THE CEREBELLAR FOSSA

Abstract

Migration of the lateral ventricles from their normal position is a common occurrence and may be extreme. An expanding lesion almost invariably displaces the ventricular system away from it, while in many cases an atrophic lesion draws the ventricular system toward it. When the ventricles are enormously dilated, as in internal hydrocephalus, the brain and adjacent portions of the lateral ventricles may migrate through a defect in the skull. Protrusions from the lateral ventricle into the cerebellar fossa through the incisura tentorii are undoubtedly of rare occurrence. We are therefore reporting in detail a case of this kind, with the clinical and postmortem observations. The probable manner of formation of these "protrusions" and their ventriculographic interpretation will also be discussed. <h3>REPORT OF A CASE</h3> S. G., a girl aged 7½ years, was admitted to the Montreal Neurological Institute on Oct. 24, 1939. There was a history of whooping cough at