Symptoms of low ICP, including orthostatic headache and nuchal rigidity
CSF rhinorrhea
Typically unilateral and watery
Typically triggered by changes in posture
Investigations
Beta-2 transferrin or beta trace protein, which is positive in CSF
Best way to differentiate CSF from normal rhinorrhea
High-resolution CT of the sinuses and skull base without contrast
Looking for defects in lateral lemella/olfactory cleft/ethmoid roof, roof of the lateral recess of the sphenoid sinus, supraorbital ethmoid roof/frontal sinus posterior table, and planum sphenoidale and posterior wall of sphenoid sinus and temporal bone
High-resolution MRI to assess the area of suspected leak as well as signs of IIH
Imaging may show suggestive signs: empty sella, arachnoid pits, erosion of skull base, widening of the subarachnoid space around the optic nerves, tortuous optic nerves, posterior globe flattening, dilated Meckel cave
May need MRV (or CTV) to exclude a transverse venous sinus stenosis
Management
Per consensus guidelines, the following assessments are recommended:
All patients with suspected CSF rhinorrhea should have ENT exam including nasal endoscopy and otologic exam
May benefit from ophthalmologic assessment for papilledema as well as assessment of visual fields
No routine prophylactic antibiotic in patients with basilar skull fractures and CSF leak
Surgical repair if leak lasts more than 7 days
Pneumococcal vaccination
International consensus guidelines suggest:
If CSF rhinorrhea is proven, they should undergo closure
Patient should be counselled on risk of meningitis
No routine prophylactic antibiotics
Further Reading
International Consensus Statement: Spontaneous Cerebrospinal Fluid Rhinorrhea. Int Forum Allergy Rhinol. 2021;11(4)794-803. doi: 10.1002/alr.22704
Clinical Practice Guidelines for Healthcare-Associated Ventriculitis and Meningitis. Clin Infect Dis. 2017;64(6):e34-e65. doi: 10.1093/cid/ciw861
References
^Allan R. Tunkel, Rodrigo Hasbun, Adarsh Bhimraj, Karin Byers, Sheldon L. Kaplan, W. Michael Scheld, Diederik van de Beek, Thomas P. Bleck, Hugh J.L. Garton, Joseph R. Zunt. 2017 Infectious Diseases Society of America’s Clinical Practice Guidelines for Healthcare-Associated Ventriculitis and Meningitis*. Clinical Infectious Diseases. 2017;64(6):e34-e65. doi:10.1093/cid/ciw861.