Transient hypothermia reduces focal ischemic brain injury in the rat

Neurosurgery. 1991 Sep;29(3):369-73. doi: 10.1097/00006123-199109000-00005.


The effect of transient hypothermia on focal cerebral ischemia was evaluated using a rat model of permanent middle cerebral artery (MCA) occlusion. MCA occlusion was performed on 10 rats at a temporalis muscle temperature of 24 degrees C (hypothermic group) and on 10 rats at 36 degrees C (normothermic group). Rats in the hypothermic group were maintained at 24 degrees C for 1 hour after MCA occlusion and then allowed to rewarm to 36 degrees C over the next 2 hours. Animals in both groups were killed 24 hours after MCA occlusion. Cerebral infarcts were visualized by staining of coronal brain sections with 2,3,5-triphenyltetrazolium chloride. Normothermic rats displayed an average infarct volume of 233.1 +/- 13.2 mm3 (standard error of the mean), whereas hypothermic rats had an average infarct volume of 166.2 +/- 22.8 mm3 (P less than 0.01). Expressed as a percentage of the volume of the right hemisphere, the normothermic group had an infarct volume of 22.1 +/- 1.5% and the hypothermic group an infarct volume of 16.0 +/- 2.2% (P less than 0.05). These results demonstrate that transient hypothermia to a temporalis muscle temperature of 24 degrees C significantly reduces subsequent infarct size in an experimental model of permanent arterial occlusion.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cerebral Infarction / pathology*
  • Cerebral Infarction / physiopathology
  • Hypothermia, Induced*
  • Ischemic Attack, Transient / pathology*
  • Ischemic Attack, Transient / physiopathology
  • Male
  • Rats
  • Rats, Inbred SHR