Observations on Brain Embolism with Special Reference to Hemorrhagic Infarction

Abstract

The embolic process, i.e., the morbid changes which develop in an organ whose blood supply has been impoverished by the embolic occlusion of nutrient arteries, constitutes an important chapter in neuropathology and one to which little thought appears to have been given in recent years. The belief is widely held that this subject was fully elucidated by the pioneers of pathology and that further investigation of it would yield little additional information. Our recent neuropathological experience has convinced us that such a view is by no means justified. There are many problems awaiting solution in this field of cerebrovascular disease, not the least of which are the cause and mechanism of hemorrhagic infarction. The paradoxical phenomenon of an occluded artery causing not only ischemic necrosis, but also vascular engorgement and hemorrhage in the region of its distribution, has been a controversial topic for at least a century, and many aspects of it are still disputed. Based on the casual observation that often in cases of hemorrhagic infarction of the brain at autopsy no arterial obstruction could be found at the appropriate site although the clinical setting suggested embolism (e.g., atrial fibrillation), we undertook a systematic assessment of our neuropathological material to investigate the relation of hemorrhagic infarction to embolism and the mechanism of hemorrhagic infarction. From these studies we were able to draw inferences concerning the dynamics of embolism.

Editors’ Note. This paper by C. M. Fisher and R. D. Adams was prepared in 1950 and was presented at the Annual Meeting of the American Association of Neuropathologists, 11 June 1950. An abstract was published in the Journal of Neuropathology and Experimental Neurology (1951) 10: 92-94. The full paper was never published and the authors were invited to have it included in this volume in its original form of 35 years ago. Some of the original illustrations could not be found, but those included here are quite representative. This study was supported in part by the Multiple Sclerosis Society of Canada.