A case report
Torres Muros B*, Montero Barnola Z.V**, Frade Cerbello D**., Mayorga
Chamorro I**, Loaiza Garreton J.P.**
* Head of Otorhinolaryngology –Head & Neck Surgery Department,
Hospital de la Axarquía.
** Otorhinolaryngology –Head & Neck Surgery Department Hospital de la
Axarquía .Torre del Mar. Málaga
The authors declare that they have no conflict of interest.
Keywords : Rhinolquorrhea, CSF leak, COVID-19, Nasopharyngeal swab
INTRODUCTION:
One of the key issues in the management of the SARS-CoV2 pandemic is the
early detection of the virus. Currently, the recommended and most
commonly used test consists of performing a polymerase chain reaction
(PCR) on a sample of nasopharyngeal specimen obtained with a swab
introduced into one or both nostrils. It is a very specific test capable
of accurately detecting low levels of viral RNA in samples containing
viral RNA. However, very little has been said about the possible
complications associated with its performance.
Case report:
A 37-year-old woman with no medical records of interest, who presented
with a 2-month history of spontaneous clear liquid unilateral nasal
discharge, which increased when the head was lowered and was not
associated to other symptoms (headache, dizziness…), that begun
after nasopharyngeal swab through the right nostril for SARS-CoV-2
screening.
Physical examination showed transparent fluid gushing out of the right
nasal cavity when the head was lowered. Flexible nasal endoscopy was
normal, not being able to identify the source of the liquid. A sample of
the liquid was collected for β-trace protein study due to the suspicion
of CSF fistula, obtaining a result of 13 mg / l (fistula reference value
> 1.1 mg / l) which supports the clinical diagnosis.
A head and paranasal sinus computed tomography (CT) scan without
contrast (Image 1) showed no intranasal pathology, but a dilatation of
the sella turcica was observed. The radiological study was extended with
an Magnetic Resonance Imaging (MRI) of the sella turcica (Image 2)
showing an enlarged sella turcica, partially empty, with liquid content
and rejection of the pituitary tissue.
Given the results of the complementary tests that confirms our clinical
diagnosis and the finding in the MRI at the level of the sella turcica,
the patient is referred to the Neurosurgery Department.
The patient was instructed on maneuvers to avoid (Valsalva, lowering the
head, blowing the nose loudly…) and warning signs that could lead us
to suspect an intracranial complication.
The patient was assessed by a neurosurgery specialist and at the time
the nasal fluid leakage had subsided and she continued to be
asymptomatic, so it was decided to follow up in 6 months.
DISCUSSION
torresIn the literature reviewed, only four cases of patients with
iatrogenic CSF fistula have been found associated with the performance
of nasopharyngeal swab for COVID-19 diagnosis, in three of them there
was an anatomical predisposition (encephalocele). The present case
raises the question of whether the fistula was favored by the
preexisting anomaly detected in the MRI at the level of the sella
turcica.
It is clear that in the study of CSF fistulas, it is important to take
an exhaustive clinical history trying to identify etiologies that
explain it. Once CSF leakage is suspected, it is necessary to
demonstrate CSF leakage and also to identify, if possible, the level of
the leak. An attempt should be made to visualize the bony defect in the
lamina cribrosa by means of nasal endoscopy. If fluid outflow is
evidenced, the nature of that fluid must be demonstrated by using
specific biochemical markers such as β2-transferrin and β-trace protein,
with high sensitivity and specificity. It is important to make an early
diagnosis because of the complications derived if left untreated,
including a higher risk of developing meningitis.
CONCLUSIONS:
Performing nasopharyngeal swab for specimen collection is a safe
procedure, but not exempt of potential complications. CSF leak should be
considered in patients with transparent rhinorrhea or postnasal drip
with a salty or metallic taste after nasopharyngeal swab. It is
important to have precise knowledge of the nasal anatomy, as well as
taking in consideration previous pathology, prior surgical intervention
or conditions that may increase the risk of complications in some
patients, before performing this test.
The swab should be introduced through the nostril parallel to the floor
of the nasal cavity and the palate (not upwards), and directed to the
nasopharynx, avoiding neck hyperextension to prevent reaching the skull
base.
It is important to properly train clinicians responsible for performing
this procedure, and for them to be aware of the possible complications
that, although rare, are very important because of its potential
complications
References:
- Garrido-Moriana NJ and González-Martínez F. Possible cerebrospinal
fluid fistula after SARS-CoV-2 PCR. Rev Esp Casos Clin Med Intern
(RECCMI). 2021 (April); 6(1): 36-38.
- Interim Guidelines for Collecting, Handling, and Testing Clinical
Specimens for COVID-19: National Center for Immunization and
Respiratory Diseases (NCIRD), Division of Viral Diseases ; 2021.
[updated January 6, 2021].
- Paquin, R., Ryan, L., Vale, F. L., Rutkowski, M., & Byrd, J. K.
(2021). CSF Leak After COVID-19 Nasopharyngeal Swab: A Case Report.
The Laryngoscope, 131(9), 1927-1929.
- Gómez G. Matías, Oliva G. Carolina, Montoya S. Francisca, Rojas Z.
David, Zemelman L. José Tomás. Cerebrospinal fluid fistula after
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Image 1 :CT scan of head and paranasal sinus. Enlargement of the Sella
turcica.
Image 2 : MRI Sella turcica enlarged, partially empty, with liquid
content and rejection of pituitary tissue.