Abstract
• It has been proposed that endogenous opioids play a pathophysiologic role in the secondary injury that follows spinal trauma, brain trauma, and cerebral ischemia. Opiate antagonists, at high doses, have been found to improve outcome in various experimental models of central nervous system injury. Thyrotropinreleasing hormone, which appears to act in part as a functional antagonist of opioid systems, has proved effective in the treatment of experimental spinal cord and brain trauma. The literature relating to these developments is reviewed, with emphasis on the potential clinical application of these classes of substances.