COVID-19 News: SARS-CoV-2 Causes Damage To Vocal Cords Along With Long Term Health Complications
According to a new study by researchers from Icahn School of Medicine at Mount Sinai, Zucker School of Medicine at Hofstra and Columbia University Medical Center nerve damage to vocal cords could be the reason why some individuals recovering from COVID-19 suffer mysterious bouts of shortness of breath for months after shaking off the SARS-CoV-2 coronavirus.
According to the study team physical exam of the larynx with awake video transnasal flexible laryngoscopy indicated that all patients demonstrated vocal folds that were not moving in normal synch with their breathing, that is, they were closing more than 50% of their glottic airway during quiet respiration when they should be opening. This abnormal vocal fold adduction could also be elicited by having the patient say the 5-word sentence “we see three green trees” and observing the vocal folds slowly closing afterwards for as long as 9 seconds. We believe that the persistent vocal fold adduction gave the patients their SOB (shortness of breath). The flattening of the inspiratory curve on spirometry corroborated the laryngeal exam findings. This is different than laryngospasm where the vocal folds suddenly slam shut for prolonged periods of time and gives a different symptom profile.
This vocal fold dysfunction, or paradoxical vocal fold movement disorder, is a vagal neuropathy, often occurring after a viral illness. One of the reasons it has traditionally been difficult to make the diagnosis of post viral vagal neuropathy is that most individuals are unable to recall that they had a viral illness, especially if the inciting event happened years ago. In the time of COVID-19, patients seem to be paying much more attention to when they began to feel ill.
The study findings are published in the peer reviewed International Journal of Pulmonary ad Respiratory Sciences. https://juniperpublishers.com/ijoprs/pdf/IJOPRS.MS.ID.555641.pdf
Typically vocal cords are meant to constrict across the airway while you're talking, vibrating in the air moving past to create the sound of your voice. When you're not talking, the vocal cords retract to allow air to more freely flow into your lungs.
However, in some patients, COVID-19 appears to damage the nerve that regulates speech, causing their vocal cords to impede breathing even when they aren't talking, said Dr Jonathan Aviv, an ear, nose and throat specialist at Mount Sinai Hospital in New York City. https://pubmed.ncbi.nlm.nih.gov/20564660/
Dr Aviv told Thailand Medical News, "Think about when you are chit-chatting. Every time you finish a sentence, your vocal cords should open so you can take a breath. Imagine if they did not open. After your third or fourth sentence, you will feel short of breath. Your airway's closed."
Dr Aviv said that the good news is this sort of breathing problem can be easily treated through a common speech therapy technique.
The study team said that they had successfully treated 18 former COVID-19 patients through a combination of speech therapy and diet modification ie avoiding foods that might exacerbate the nerve irritation.
Dr Aviv said, "All the patients resolve their shortness of breath. You can see it when they come back. Their vocal cords are now moving normally.”
According to Dr Aviv, the vagus nerve runs from the brain and controls voice, swallowing, breathing and coughing, previous research has shown that a vagus nerve injury can cause the vocal cords to fail to retract, impeding air flow.
He said, "If the vagus has been towel-snapped by a virus, it's going to not function normally, and one of the manifestations is shortness of breath with or without cough.”
Physicians have been confounded by occasional COVID-19 patients who continue to have shortness of breath even though the inflammation caused by the viral infection has gone away and imaging scans show no lasting lung injury, said Dr Joseph Khabbaza, a pulmonologist with the Cleveland Clinic in Ohio.
Dr Khabbaza said, "We're seeing a bunch of people that have normal breathing tests and are not responding to asthma inhalers. They've got real symptoms but their testing is coming up normal."
In order to see if the vocal cords might be the culprit, Dr Aviv and his colleagues ran a tiny camera smaller than a shoelace down the noses of 18 COVID-19 "long haulers" to get a closer view of their airway.
Interestingly enough, the camera showed that individual's vocal cords were failing to pull back properly.
Dr Aviv said, "I show them the video, and they basically fall off the examining chair. They cannot believe what's going on."
Typically this sort of vocal cord dysfunction is treated using "respiratory retraining," a series of exercises designed to improve function of the respiratory muscles, he said.
He also urged patients to avoid highly acidic foods that can irritate the vagus nerve, including flavored beverages from cans or bottles, citrus fruits, tomato sauce, vinegar and wine.
It is highly recommended that COVID-19 patients who continue to have persistent shortness of breath even after their other symptoms have faded should discuss this possibility with their doctor.
Upon reading Aviv's paper, Dr Khabbaza said he has a couple of patients he plans to check out for possible vocal cord problems.
Dr Khabbaza said, "If you're stuck with shortness of breath, I think this sounds like something that is worth investigating because we know it responds very well to speech therapy. This vagal neuropathy would be one of those things that would cause shortness of breath but not respond to the most common treatments for shortness of breath after a COVID infection."
The study team concluded, “We feel that in a time of understandably great emphasis on serial CT scans of the chest to evaluate patients with persistent shortness of breath, offering this other, emerging diagnostic possibility to account for such symptoms may be helpful to the clinician. In patients with persistent SOB, with or without cough, where the pulmonary imaging is unremarkable whether or not they tested positive for, or have antibodies to, COVID-19, but certainly with positive testing, one should consider both a spirometry and an otolaryngology evaluation. This symptom complex may be due to a virus-related cranial neuropathy which can be readily identified with office laryngoscopic evaluation and then treated, with restoration of premorbid functionality.”
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