Temperature modulation (hypothermic and hyperthermic conditions) and its influence on histological and behavioral outcomes following cerebral ischemia

Core temperature (T-c) is a critical determinant of the severity of neural damage that results from focal or global ischemia, Former studies indicated that especially intra-ischemic but also post ischemic mild hypothermia sig nificantly decreased necrotic neural damage of a focal or global insult, as assessed between 3-7 days post-insult. More recent work shows that prolong ed post-ischemic hypothermia reduces neural damage and inhibits associated behavioral deficits for up to one year after the insult (i.e. true neuropro tection with behavioral preservation). Alternatively, increases in core tem perature via external heating or with pyrogens resulting from bacterial inf ections, at the time of the global ischemia insult worsen the neural damage of ischemic animals from those of respective normothermic controls given t he same insult. This is paralleled in the clinical setting whereby similar to 50% of ischemic patients develop fevers within 2 days of the insult and have worsened neurological outcomes than non-febrile patients. The review d iscusses the possible mechanisms of neuroprotection of hypothermic therapy from cerebral ischemia as well as mechanisms involved in the exacerbation o f neural damage of hypoxic ischemia under hyperthermic conditions. Question s are raised as to whether the medical community has sufficient evidence to begin appropriate hypothermic therapy of acute stroke patients. The import ance of accurate monitoring core temperatures of all suspected stroke patie nts is emphasized, noting the differences in temperature that can occur wit h age, sex, medication or lifestyle so that appropriate temperature treatme nt could be implemented, if required.