Intracerebral temperature in neurosurgical patients: intracerebral temperature gradients and relationships to consciousness level.

Information regarding human brain temperature is still rather sparse, which is surprising giving the no longer recent findings that the mammalian brain is very sensitive to minor variations in temperature. We therefore report the results of intracranial temperature monitoring in thirty neurosurgical patients. Intraventricular temperature was monitored with a thermocouple specifically designed for the purpose, and introduced through a plastic catheter used for monitoring of intracranial pressure, with simultaneous measurements of rectal and epidural temperature with commercially available thermocouples. Human intraventricular temperature is higher than central core temperature, and there is also a temperature gradient within the brain, with the central parts being warmer than the surface. The presence of an intracerebral temperature gradient was confirmed in two patients undergoing stereotactic thalatomy. We found no clear evidence for a correlation between consciousness level and brain temperature. Observations of brain temperature changes after clinical diagnosis of brain death are also reported.