The histologic effect of intraventricular injection of metrizamide

Abstract

A patient with sudden apoplexy and coma was found to have hydrocephalus on computed tomographic scan, and metrizamide was instilled into the ventricles. Subsequent autopsy disclosed a brainstem infarct secondary to a primary dissecting aneurysm of the basilar artery, and a histologic picture of encephalitis in the walls of the lateral and third ventricles. Metrizamide may cause pathologic changes that must be recognized for the correct interpretation by the pathologist of tissue sections previously exposed to metrizamide. In the present case, the changes were seen 11 days after exposure of the tissue to metrizamide, consonant with the time course of similar changes observed in animals. The localization of the cellular infiltrates to the Virchow-Robin spaces corroborates evidence from the literature that metrizamide enters brain parenchyma via these spaces.