Hot nose sign
The hot nose sign refers to increased perfusion in the nasal region on nuclear medicine cerebral perfusion studies in the setting of brain death. The absent or reduced flow in the internal carotid arteries is thought to lead to increased flow within the external carotid arteries and subsequent increased perfusion in the nasal region. 1
Although the sign is cute, it is not of any real diagnostic value. The medico-legal importance of brain death is such that direct assessment of cerebral perfusion is required for diagnosis irrespective of how hot or cold a nose may appear.