Which finding indicates a CSF leak after head trauma?

• A. PERRL
• B. Clear or pink drainage from nose/ears (basilar skull fracture sign)
• C. Central support structure of vertebrae
• D. C1-C7 vertebrae in neck

Answer: (D)

CSF leaks after head trauma show up when a skull base fracture creates a path for CSF to escape into nasal or ear passages. The hallmark is clear, watery drainage from the nose (rhinorrhea) or ears (otorrhea), sometimes described as a clean, persistent discharge and may be confirmed with tests like beta-2 transferrin or by noting a halo on a collected sample. This leak indicates involvement of the subarachnoid space and basilar skull fracture.

Pupil responses (PERRL) reflect cranial nerve function and general brain perfusion, not leakage of CSF. The remaining options describe anatomy or structures of the spine, which don’t indicate a CSF leak. Therefore, the presence of clear drainage from the nose or ears after head trauma is the finding that points to a CSF leak.