Department of Neurosurgery, OSF Saint Francis Medical Center, IL, 61637.

The COVID-19 pandemic has encouraged the widespread use of screening tests for early, precise disease diagnosis. Tests using nasopharyngeal swabs are among the most frequently used. We describe the case of a 58-year-old woman who experienced meningitis after a cerebrospinal fluid leak from a bone defect in the sphenoid sinus occurred immediately after a pre-procedural COVID screening test. The potential risk associated with collecting nasopharyngeal swabs should be known to providers. Patients who have had sinonasal or cranial base surgery in the past may want to seek other COVID screening tests.

The medical community has done a lot of study into screening and treatment techniques since the COVID-19 outbreak started in the United States in 2019. As isolation seems to be the only practical method of preventing the spread of infection, virus testing is still an essential component of creating a quarantine strategy [1]. Nasopharyngeal swab testing is still a prominent diagnostic technique, despite the fact that the true benefit of widespread testing depends on the test's accuracy and is not well understood [2, 3]. Compared to a lower respiratory tract specimen, an upper respiratory swab is simpler to obtain and less taxing on the patient.

Reverse-transcriptase polymerase chain reaction testing is extremely specific and may be more sensitive than oropharyngeal swabs for identifying viral RNA from nasal materials [2]. Surgery and tool introduction in the upper sinuses and nasal cavity have the potential to cause iatrogenic cerebrospinal fluid leak because of their proximity to the intracranial cavity [4].

In 16% of instances, iatrogenic or cranial and sinonasal surgical trauma is present, which is a common source of cerebrospinal fluid (CSF) leak at the base of the skull and sinuses [4]. It is possible for spontaneous leaks to happen and they may do so when idiopathic intracranial hypertension is present [4]. On the basis of clinical presentation, the diagnosis of CSF leak from the nasal sinuses is suspected, and beta-2-transferrin testing can reliably confirm this diagnosis.

Both fine CT imaging of the skull base and brain MRI can aid in the diagnostic process [1, 3]. Meningitis risk is increased by persistent CSF leak, which is usually treated surgically.

This work was done in conformity with the local Institutional Review Board's guidelines, the World Medical Association's Code of Ethics, and the Declaration of Helsinki. Our patient, a 58-year-old female with a complicated cardiac history, had her left ventricle's double-inlet repaired as a child, had a total heart block that required a pacemaker, had deep venous thrombosis in her legs in the past, was in stage III chronic kidney disease, and had cirrhosis. She had a BMI of 33 and no known history of idiopathic intracranial hypertension. She was scheduled for an outpatient image-guided paracentesis because she had recurrent ascites from right-heart failure. She underwent COVID-19 testing using a nasal swab as part of the pre-operative screening procedure.

After having her nasal swab tested, the patient started to experience clear nasal drainage 48 hours later. This was constant and frequently accompanied by stooping or an upright posture. She underwent outpatient testing of her rhinorrhea fluid, which revealed beta2-transferrin levels that indicated a CSF leak. She was unable to have a brain MRI since she had a cardiac pacemaker. Upon receiving a head CT, it was discovered that the left side of the posterior wall of the sphenoid sinus had a tiny bone defect (about 4-5 mm).

The patient was taken to the emergency room by her husband around eight weeks following this treatment because she was feverish, confused, suffering from a headache, neck discomfort, and exhaustion. Physical examination results revealed nothing obviously incorrect. Her laboratory tests revealed a WBC of 60,000 cells/uL, lactic acid of 2.2 mmol/L, and no changes in electrolytes, ammonia, or renal function. She was assessed using the sepsis protocol. After being admitted, she started receiving empiric antibiotics in the intensive care unit. Streptococcus pneumoniae was detected in her blood cultures. Culture of urine revealed no growth.

On positron emission tomography imaging of the chest, abdomen, or pelvis requested by the infectious disease consultant, she had no recognised cause of her bacteremia. She was put on bed rest, and it was seen that the CSF rhinorrhea persisted.

The patient had a lumbar puncture that was fluoroscopically guided, however it was unsuccessful because of the patient's tolerance and body habitus. After several days of bed rest and head elevation, her rhinorrhea and mental condition eventually recovered, and there was no CSF leak discovered. She was given long-term intravenous access so that she could receive antibiotics outside of the hospital to treat her sepsis. A six-week course of ceftriaxone and vancomycin therapy was planned by the infection disease expert who felt that the patient's septicemia was caused by a chronic CSF leak and related meningitis from seeding in the nasal cavity.

It is unknown if the sphenoid sinus bone defect was present before the patient underwent COVID nasal swab testing; this diagnostic procedure may be responsible for the patient's CSF rhinorrhea because the patient underwent no prior cranial imaging. She was discharged after two weeks of inpatient care with intensive clinical supervision.

Nasopharyngeal swab testing is now a commonly used technique for diagnosing and screening COVID-19. The healthcare provider must carefully place a swab parallel to the palate, proceed "until resistance is encountered," then slowly remove the swab while rotating it, according to the Centers for Disease Control's recommendations for clinical specimen collection in the nasopharynx [5]. 8 to 10 cm can separate the nostril's opening from the nasal cavity's back wall. The sphenoid sinus normally sits above the hard palate, therefore the force needed to strike the upper or posterior walls of the sinus would not go in a straight line with the palate.

Anterior nasal swab sampling, a different method suggested by the CDC, advises sampling no deeper than 3/4 to 1 inch into the nasal cavity [5]. Our account of a CSF leak following the collection of a nasopharyngeal specimen with a bone defect in the sphenoid sinus demonstrates a distinct potential risk of straying from the suggested anatomical collection site. It's likely that a pre-existing bone defect filled this area, and the insertion of the nasopharyngeal swab led to a dural perforation. Due to bacterial flora from the sinonasal mucosa contaminating the subarachnoid space, CSF leak is a well-established risk factor for meningitis [3]. If left untreated, meningitis will develop in about 10% of patients with a CSF leak within a year, causing considerable morbidity and a high case-fatality rate [4].

Consider using oropharyngeal or anterior nasal swabs as COVID screening tests in place of blood tests since both procedures are showing signs of increasing sensitivity. This may be especially important for individuals who have a history of traumatic skull or brain injury, whether from accidents or previous surgical treatments. Before doing a nasal swab test, healthcare professionals should ask about previous surgical or procedural history.

As long as the CDC's recommended procedures are followed, nasal swab testing for COVID is still a typical sample method. Patients having a history of brain trauma or surgery on the sinuses or skull base may benefit from alternative swab collection sites if being checked for COVID since nasal treatments carry a risk of CSF leak.

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2. Zitek T. The appropriate use of testing to COVID-19.West J Emerg Med. 2020; 2(3):470-472. [DOI: 10.5811/westjem.2020.4.47370].

3. Daudia A, Biswas D, Nick SJ. Risk of Meningitis with Cerebrospinal Fluid Rhinorrhea. Ann Otol Rhinol Laryngol. 2008;116:902-905. [DOI:10.1177/000348940711601206].

4. Yadav Y, Parihar V, Janakiram N, Pande S, Bajaj J, NamdevH. Endoscopic management of cerebrospinal fluid rhinorrhea. Asian J Neurosurg. 2016; 11(3):183-193. [DOI: 10.4103/1793-5482.145101].

5. CDC Coronavirus Testing Overview. https://www.cdc.gov/coronavirus/2019-ncov/lab/guidelines-clinical-specimens.html. (Accessed 27 October 2021).

Nolan Winslow. Following COVID-19 nasal swab testing, cerebral spinal fluid rhinorrhea: case report. Insights of Clinical and Medical Images 2022.