Hyperthermia induced brain oedema: current status and future perspectives.

Recent years have witnessed a large number of deaths due to hyperthermia and heat-related illnesses across the globe in human population resulting in great social and medical problems. The detailed mechanisms and probable therapeutic measures have still not been worked out. Sporadic autopsy reports show profound brain swelling leading to compression of vital centers that could be responsible for instant death. Increased permeability of the blood-brain barrier (BBB) and brain swelling is also seen in experimental models of heat stress. It appears that hyperthermia is instrumental in opening of the BBB either directly or indirectly leading to vasogenic oedema formation, a feature crucial to molecular and cellular alteration in the brain inducing cell and tissue injury. The probable mechanisms and functional significance of heat induced brain oedema and BBB damage in relation to neurodegenerative changes are discussed.