Septic Cerebral Embolism

Abstract

In order to study the effects of septic embolism on neurovascular structures, cerebral infarction was produced in a series of dogs by injecting silicone rubber cylinders through an internal carotid artery cannula. Each embolic particle was first incubated with one of four known bacterial pathogens. Death occurred in three animals on the second postoperative day, at which time ten other moribund dogs were sacrificed. Eleven animals made apparently uneventful recoveries from early hemiplegia and appeared well when sacrificed electively one to five weeks after embolism. Autopsies revealed subarachnoid and acute subdural hemorrhages in the early group with gross and microscopic evidence of mycotic aneurysm in each instance. Chronically surviving animals showed histological lesions in the putamen or temporal pole consistent with brain abscess. In this series, mycotic aneurysm with hemorrhage was an extremely dramatic complication of emboli infected with the virulent pathogens, Staphylococcus aureus and Escherichia coli, while brain abscess developed insidiously in ischemic areas, after embolism with the opportunistic pathogens, Streptococcus viridans and Enterococcus.