POSTISCHEMIC HYPOTHERMIA - A CRITICAL-APPRAISAL WITH IMPLICATIONS FORCLINICAL TREATMENT

The use of hypothermia to mitigate cerebral ischemic injury is not new . From early studies, it has been clear that cooling is remarkably neu roprotective when applied during global or focal ischemia. In contrast , the value of postischemic cooling is typically viewed with skepticis m because of early clinical difficulties and conflicting animal data. However, more recent rodent experiments have shown that a protracted r eduction in temperature of only a few degrees Celsius can provide sust ained behavioral and histological neuroprotection. Conversely, brief o r very mild hypothermia may only delay neuronal damage. Accordingly, p rotracted hypothermia of 32-34 degrees C may be beneficial following a cute clinical stroke. A thorough mechanistic understanding of postisch emic hypothermia would lead to a more selective and effective therapy. Unfortunately, few studies have investigated the mechanisms by which postischemic cooling conveys its beneficial effect. The purpose of thi s article is to evaluate critically the effects of postischemic temper ature changes with a comparison to some current drug therapies. This a rticle will stimulate new research into the mechanisms of lengthy post ischemic hypothermia and its potential as a therapy for stroke patient s.