Special aspects of severe head injury: recent developments.

Trauma in general, and head injury in particular, is the most frequent cause of mortality and morbidity in those aged up to 45 years. Outcome from severe head injury depends on the nature and severity of the primary lesion, and the manifestations of secondary brain damage of extra- and intracranial origin. The most important sequela is cerebral ischaemia resulting from intracranial hypertension caused by, for example, traumatic brain swelling or intracranial haemorrhage and/or systemic complications, of which arterial hypotension is the most significant. Because treatment so far is limited in principle to general symptomatic measures, continuing improvements in patient management is required on a comprehensive basis. In this context, major efforts are being made all over the world, not only to assess the current efficacy of, for example, logistics, organization and patient management in severe head injury, but also towards development of a consensus aimed at standardizing management and treatment procedures. With regard to the predominant influence of secondary ischaemia of the brain, recent experimental and clinical pathophysiological studies focus on the quality of cerebral blood flow, including the intriguing phenomenon of post-traumatic vasospasm. Other research objectives are concerned with the role of cytokines, leucocyte-endothelial interactions and molecular genetics in severe head injury (e.g. illuminated by the emerging role of the apolipoprotein E gene). Finally, the formation of international organizations, the American and European Brain Injury Consortium, is noteworthy. Although their primary objective is the development of guidelines for clinical trials, future objectives are conceivably more far spread and influential. It can be hoped, therefore, that the unacceptably poor outcome from severe head injury until now can be improved. Moreover, alleged management discrepancies between up-to-date trauma centres and rural hospitals may be eliminated.