Fact Check

Did a Woman’s Brain ‘Leak’ After a COVID Swab Test?

She had an extremely rare preexisting condition.

Published Feb 5, 2022

LITTLETON, Mass. – A medic with the Massachusetts National Guard takes a nasal swab that will be used to test for COVID-19 with a resident of the Life Care Center of Nashoba Valley, Littleton, Mass., April 3, 2020. The Massachusetts National Guard worked with the facility’s staff to administer COVID-19 tests to help prevent the spread of the virus. (Army National Guard Photo by Staff Sgt. Kenneth Tucceri) (The National Guard/Wikimedia Commons)
Image Via The National Guard/Wikimedia Commons
A woman's brain began leaking because of a COVID-19 nasal swab test.
What's True

After swabbing for COVID, a woman began leaking cerebrospinal fluid, which is found in the protective lining of the brain and spine. However...

What's False

Doctors theorized that the trauma and leakage occurred because of a preexisting defect in the woman's skull, not the swab itself. Though another case of cerebrospinal fluid leak reportedly occurred in a man who did not have a preexisting condition, doctors said it was the first known case of its kind. Either way, it is an extremely uncommon injury and most people should not be concerned about undergoing a nasal swab for COVID-19 diagnosis.

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Since nasal swabs have become commonplace for COVID-19 testing, the fears around them have also grown, resulting in certain incidents becoming exaggerated and distorted as a result. One particular incident involving a woman in Iowa back in 2020 generated headlines and questions from our readers, with claims that undergoing a swab resulted in a “leak” from the woman's brain through her nose. 

This so-called “leak” was a result of a very rare preexisting condition, and not because the swab was able to actually pierce the brain. The Mirror claimed in October 2020 that a COVID test caused the woman’s brain to “leak.” 

That particular case was reported in the medical journal JAMA Otolaryngol Head & Neck Surgery, in October 2020. After a woman swabbed herself for COVID-19 before undertaking a hernia operation, fluid began leaking from her nose, she developed a headache and started vomiting. The report identified the fluid as cerebrospinal fluid, which is the protective lining around the brain and spine. 

The report concluded that they had never encountered a case like this before, and the leak was not caused by the swab itself, but by the woman’s preexisting condition, which was a skull base defect:

To our knowledge, this is the first report of an iatrogenic CSF leak after a nasal swab for COVID-19. Of prior reported iatrogenic CSF leaks from intranasal procedures, surgical trauma at the cribriform plate is the culprit in CSF leaks 8% to 58% of the time.3 Idiopathic intracranial hypertension is a risk factor for meningocele formation,4 and this patient had an undiagnosed skull base defect at the fovea ethmoidalis that was present on imaging dating back to 2017. We therefore theorize that the swab itself did not result in a violation of the bony skull base, but rather the invasive test caused trauma to the patient’s preexisting encephalocele. [Emphasis added]

Another similar case was reported in a September 2021 report in JAMA. In that instance, the COVID-19 swab resulted in an extremely rare cerebrospinal fluid (CSF) leak caused by the test. The report concluded:

Complications after nasal swab testing can be expected during the COVID-19 pandemic owing to an increase in nasal swab testing. Every instance of unilateral clear water rhinorrhea that appears after transnasal testing must be considered a potential CSF leak. To our knowledge this is the first case report presenting CSF fistula following the nasal swab testing in a healthy man with no preexisting skull base condition. [Emphasis added]

A LiveScience report added important context highlighting how rare such a case was: “... only a handful of CSF leak cases linked with COVID-19 tests have been reported worldwide since the pandemic began, out of the hundreds of millions of COVID-19 tests conducted.” 

According to a report in The Conversation, which was also published on this website, the woman’s skull defect was very rare, and “one in 10,000 babies are born with a defect like this, but the rate at which it occurs in adults is unknown.” Carl Philpott, Professor of Rhinology and Olfactology, University of East Anglia, advised in the article: 

It is extremely unlikely for any person who doesn’t have this pre-existing weakness in the nose to cause any damage with a swab. However, a good tip when swabbing the nose is to remember that the inside of the nose travels back, towards the back of the head, and not up. So any swabbing of the nose should involve pointing the swab towards the back of the head in the same direction as you would point the swab towards your tonsil when you swab your mouth – which is part of the same test.

Given that the woman’s and even the man’s conditions are both very rare, and the first of such incidences recorded, we rate this claim as a “Mixture.” 


Best, Shivali. “Coronavirus Swab Test Went so Far up a Woman’s Nose It Caused Her Brain to Leak.” Mirror, 2 Oct. 2020, https://www.mirror.co.uk/science/coronavirus-swab-test-went-far-22779327. Accessed 2 Feb. 2022.

Knížek, Zdeněk, and Roman Michálek, Jan Vodička, et al. "Cribriform Plate Injury After Nasal Swab Testing for COVID-19." JAMA Otolaryngol Head Neck Surg, 2021. https://jamanetwork.com/journals/jamaotolaryngology/fullarticle/2771362.  Accessed 2 Feb. 2022. 

“No, You Cannot Pierce Your Brain with a Swab Test.” Snopes.Com, https://www.snopes.com/news/2020/10/02/no-you-cannot-pierce-your-brain-with-a-swab-test/. Accessed 2 Feb. 2022.

Rettner, Rachael. “COVID-19 Test Caused Man’s 9-Month-Long Brain Fluid Leak.” Livescience.Com, 9 Sept. 2021, https://www.livescience.com/runny-nose-brain-fluid-covid-19-test.html. Accessed 2 Feb. 2022.

Sullivan, Christopher Blake, and Adam T. Schwalje, Megan Jensen, et al. JAMA Otolaryngol Head Neck Surg, 2020. "Cerebrospinal Fluid Leak After Nasal Swab Testing for Coronavirus Disease 2019." https://jamanetwork.com/journals/jamaotolaryngology/fullarticle/2771362. Accessed 2 Feb. 2022.

Nur Nasreen Ibrahim is a reporter with experience working in television, international news coverage, fact checking, and creative writing.

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