Compression-induced Brain Edema: Regional Changes of Superoxide Free Radicals in the Development of Vasogenic Edema and Tissue Damage in Intracranial Hypertension

Abstract

Intracranial hypertension following severe head injury continues to remain a serious problem affecting morbidity and mortality. The major causes of such a seriously elevated intracranial pressure (ICP) are mainly either vascular engorgement (brain swelling) or brain edema. Engorgement occurs when there is a loss of normal regulation of vascular tone, and brain edema can occur due to an increased vascular permeability [7]. Recent studies have indicated that the oxygen derived free radicals may modify the changes of vascular tone, permeability and cell membrane damage in ischemic injury [1], resulting in brain edema and swelling. Despite this conceptual framework, previous studies have failed to elucidate the precise location, characteristics, and magnitude of free radical-induced alterations of the injured tissue. An accurate understanding of the regional changes in free radicals occurring in intracranial hypertension-injured tissue is important for investigating the mechanisms of brain edema and swelling in the central nervous system. One of the problems in such research is that free radicals are extremely labile and difficult to detect in vivo.