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Hot nose sign - brain death

Case contributed by Andrew Dixon
Diagnosis certain

Presentation

Motor bike accident ?brain death

Patient Data

Age: 30 years
Gender: Male

Tc-99m HMPAO Brain Perfusion

Nuclear medicine

Figure 1A & B: Tc-99m HMPAO scan shows absent cerebral perfusion consistent with brain death. Relatively increased nasal region perfusion due to preserved external carotid artery flow is often termed the 'hot nose sign'. 

Figure 2

Annotated image

Dotted lines encircle the cerebral hemispheres which show absent perfusion consistent with brain death. Arrow points to the increased nasal region perfusion, the so-called 'hot nose sign'. 

Case Discussion

Hot nose sign  - an indirect sign of brain death on nuclear medicine cerebral perfusion studies. Absence of internal carotid artery flow leads to increased external carotid artery flow and subsequent increased perfusion in the nasal region. Although the sign is cute, it is not of any real diagnostic value as the medico-legal importance of brain death is such that direct assessment of cerebral perfusion is required.1 

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