Theoretical evaluations of therapeutic systemic and local cerebral hypothermia

PurposeTo simulate cerebral temperature behaviour with hypothermia treatment applying different cooling devices and to find the optimal brain temperature monitoring.MethodsModels based on hourly temperature values recorded in patients with severe aneurysmal subarachnoid hemorrhage, taking MRI data, thermal conductive properties, metabolism and blood flow into account were applied to different scenarios of hypothermia.ResultsSystemic hypothermia by endovascular cooling leads to an uniform temperature decrease within the brain tissue. Cooling with head caps lead to 33 °C only in the superficial brain while the deep brain remains higher than 36 °C. Cooling with neckbands lead to 35.8 °C for dry and 32.8 °C for wet skin in the deep brain.ConclusionsWith head caps temperatures below 36 °C cannot be reached in the deep brain tissue, whereas neckbands, covering the carotid triangles, may lead to hypothermic temperatures in the deep brain tissue. Temperature sensors have to be applied at least 2 cm below the cortical surface to give values representative for deep brain tissue.