[Intracranial temperature measurements in brain death]

Area of Science:

• Neurology
• Physiology
• Critical Care Medicine

Context:

• Intracranial temperature often differs from core trunk temperature.
• Limited data exists on temperature dynamics in brain death.
• Comatose patients (GCS 3-9) post-head trauma or stroke were studied.

Purpose:

• To investigate the relationship between intracranial, trunk, and tympanic temperatures in patients with and without brain death.
• To understand temperature changes in the brain during the progression to brain death.

Summary:

• In unconscious patients without brain death, intracranial and trunk temperatures were similar, with intracranial being slightly higher.
• Brain death onset led to a significant drop in intracranial temperature (2-4°C lower than trunk temperature) over 6-12 hours.
• Tympanic temperature initially correlated with brain temperature but diverged during brain death, no longer mirroring intracranial changes.

Impact:

• Brain death causes a dissociation between intracranial and core trunk temperatures.
• Intracranial temperature falling below arterial blood temperature suggests cessation of brain metabolism.
• These findings may represent a specific physiological state unique to brain death.