An Iowa woman’s nasal swab test for covid-19 caused her to leak spinal fluid, her doctors report, in what appears to be the first recorded injury of its kind related to the novel coronavirus. But don’t worry too much about something similar happening to you during a swab test – the unfortunate incident was probably only possible because the woman unknowingly had a rare congenital condition that left part of her skull open.
The clinical case was published Thursday in the scientific journal JAMA Otolaryngology – Head & Neck Surgery. According to the report, the woman had gone to her doctor with complaints of a runny nose, stiff neck, headache, sensitivity to light and a strange metallic taste in her mouth. A physical exam revealed some sort of mass on the right side of her nasal cavity, while tests on the woman’s snot showed it contained spinal fluid.
When she tried to piece together how she got sick, the woman told doctors she had recently gotten a swab test for covid-19 as a precaution before her elective hernia surgery. Soon after, she started experiencing a runny nose and headache, as well as a bout of vomiting. Once an MRI was done, the problem was clearly identified. The woman, it turned out, had something known as an encephalocele: a sac-like formation of brain matter, membrane, and spinal fluid protruding from an opening in the skull that shouldn’t be there.
An encephalocele (pronounced en-sef-a-lo-seal) is a rare birth defect, it was thought to affect only one in 10,000 newborns per year in the United States. They occur when the neural tube, the precursor of the central nervous system in a fetus, does not develop properly, causing some bones in our skull to not fuse normally. They are usually large enough to be easily seen on an ultrasound or once the baby is delivered. But sometimes, especially when the opening is around the nasal cavity, they are small enough not to be detected, even for many decades, as happened to the Iowa woman, who is in her 40s. In this case, his encephalocele was actually found on a CT scan taken three years earlier in 2017, but doctors at the time only diagnosed her with a sinus infection.
WWhile nasal swabs can certainly be unpleasant (speaking from personal experience), doctors in this case think it is unlikely that the tampon pierced her skull hard enough to cause a leak on its own. There have been reports of doctors who have injured the nasal cavity to the point of causing spinal fluid to leak, but it is usually during a surgical procedure. So while this may be the first report of spinal fluid leakage linked to a swab test for covid-19, there are likely some heavy extenuating circumstances at play here.
“We therefore theorize that the swab itself did not cause a violation of the bony skull base, but rather the invasive test caused trauma to the patient’s pre-existing encephalocele,” the authors wrote.
As for the woman, the doctors were able to successfully drain some of her encephalocele and plug the opening with a tissue graft.
As rare as this series of events may be, the authors suggest that people with a known history of similar skull defects or previous sinus injuries are tested for covid-19 in ways other than a nasal swab. Saliva tests are now available, with some evidence suggesting they may be as accurate as the nasal swab. And healthcare professionals can swab the back of the throat instead of deep into the nasal cavity. But for now, these methods are still not as widely accessible or applied as the nasal swab test.