Clear, unilateral rhinorrhea drainage that increases at times of relatively increased intracranial pressure and has a metallic or salty taste is suspicious for CSF rhinorrhea.3 It can occur following skull‐base trauma (eg, cribriform plate, temporal bone), endoscopic sinus surgery, or neurosurgical procedures, or have a spontaneous etiology.3,4
Modalities to confirm CSF rhinorrhea include radionuclide cisternography and testing of fluid for the halo sign, glucose, and the CSF-specific proteins β‐2 transferrin and β-trace protein.3,4 High‐resolution CT is the imaging method most commonly used for localizing a CSF leak.4
Treatment is provided in the hospital
Patients with CSF rhinorrhea typically require inpatient management with bed rest, head-of-bed elevation, and frequent neurologic evaluation, as persistent CSF rhinorrhea increases the risk for meningitis, thus necessitating surgical intervention.3,5 Some cases resolve with bed rest alone. Endonasal endoscopic repair of CSF leaks has become the standard of care because of its high success rate and lower morbidity profile.4
The preferred treatment method for encephalocele is surgical removal after diagnosis is confirmed with CT or magnetic resonance imaging.6
Our patient underwent surgery to remove the encephalocele. The surgeons reported no evidence of fracture.
The final cause of her CSF leak is still uncertain. The surgeons felt confident it was due to ethmoidal encephalocele, a form of neural tube defect in which brain tissue herniates through structural weaknesses of the skull.6-8 While more common in infants, encephalocele can manifest in adulthood due to traumatic or iatrogenic causes.7,8
There is a previous report of encephalocele with CSF leak after COVID-19 testing.9 This case report suggests the possibility of a nasal swab causing trauma to a patient’s pre‐existing encephalocele—a probability in our patient’s case. It is unlikely, however, that the nasal swab itself violated the bony skull base.
THE TAKEAWAY
This case exemplifies how unexplained local symptoms, a high index of suspicion, and adequate work-up can lead to a rare diagnosis. Diagnostic strategies employed for cases of CSF rhinorrhea vary widely due to limited evidence-based guidance.4 Unilateral rhinorrhea with clear fluid that increases at times of increased intracranial pressure, such as bending over, should prompt suspicion for CSF rhinorrhea. With millions of people getting nasal swabs daily during the COVID-19 pandemic, it is even more important to keep CSF leak in our differential diagnosis.
CORRESPONDENCE
Eliana Lizeth Garcia, MD, BS, BA, University of New Mexico Health Sciences Center, 1209 University Boulevard NE, Albuquerque, NM 87131-5001; elianalg@hs.uci.edu