Moderate hypothermia and brain temperature in patients with severe middle cerebral artery infarction

Elevated temperature is known to facilitate neuronal injury after ischemia. After head injury a gradient between temperature and body temperature of up to 3 degrees C higher in the brain has been reported. Hypothermia may limit some of the deleterious metabolic consequences of such increased temperature. In 20 patients who had suffered severe ischemic stroke in the middle cerebral artery (MCA) territory, intracerebral temperature combined with ICP monitoring was recorded using two different thermocouples, with epidural, and parenchymatous measurements. Mild hypothermia was induced using cooling blankets. Patients were kept at 33 degrees C core temperature for 48 to 72 hours. In all patients brain temperature exceeded body-core temperature by at least up to 1 degree C (range 1.0-2.1 degrees C). Systemic cooling was effective and sustained hypothermic (33-34 degrees C) brain temperatures. With mild hypothermia critically elevated ICP values could be controlled. 12 patients survived the hemispheric stroke with a mean Barthel index of 70. Severe side effects of hypothermia were not detected. After MCA stroke, human intracerebral temperature is higher than central body-core temperature. Mild hypothermia in the treatment of severe cerebral ischemia using cooling blankets is safe and does not lead to severe side effects. Mild hypothermia can help to control critically elevated ICP values in severe space-occupying stroke and may improve clinical outcome in these patients.