Lack of awareness surrounding exercise-induced paradoxical vocal fold movement (PVFM) as a cause of dyspnea may contribute to athletes being misdiagnosed and improperly treated.
Patients are often mistakenly diagnosed with asthma and treated with inhalers, which are not effective in PVFM, explained Natasha Mirza, MD, Associate Professor of Otorhinolaryngology-Head and Neck Surgery at the Hospital of the University of Pennsylvania, Director of the Penn Voice and Swallowing Center, and Chief of the Division of Otolaryngology at the Veterans Administration Medical Center. Fortunately, a variety of effective treatment options exist for treating PVFM.
Characteristics of PVFM
PVFM, often triggered by exercise, is a condition in which the vocal folds don’t open properly causing dyspnea, explained Jonathan Aviv, MD, FACS, Professor of Otolaryngology-Head and Neck Surgery, Director of the Division of Laryngology, and Medical Director of the Voice and Swallowing Center at Columbia University Medical Center, New York-Presbyterian Hospital.
When PVFM is present, the vocal folds will shut during breathing or after patients have finished speaking, said Dr. Aviv. The condition is usually characterized by vocal fold closure consisting of 50% of the glottic airway.
During PFVM, the patient becomes a clavicular rather than a diaphragmatic breather, said Bernice Klaben, PhD, Associate Professor in the Department of Otolaryngology at the University of Cincinnati. If patients are breathing hard, they might experience stridor on inhalation, she added.
With athletes, we’ll have them start this type of [diaphragmatic] breathing in a supine position, gradually move them to upright, and then work them on a treadmill or observe them while sprinting.
-Bernice Klaben, PhD
PVFM in Athletes
PVFM can occur in any athlete, said Dr. Klaben, but it generally occurs in those who are overachievers and very good at their sport, she said. Although the literature states that PFVM is more prevalent in women, Dr. Klaben sees about the same number of males and females in her practice.
Other practitioners interviewed for this article find that PFVM occurs mostly in females. Dr. Aviv generally sees exercise-induced PFVM most often in high-achieving young women. It’s an anecdotal observation, and we don’t know why this occurs, but patients are often straight-A students who excel at athletics, he said.
Barbara Mathers-Schmidt, PhD, Professor and Chair of Communication Sciences and Disorders at Western Washington University, also tends to see more women in her practice. I’m not sure why, she said. You can leap to the assumption that women are more likely to seek help, but I’ve also seen male patients of all ages who are football players, runners, and cyclists.
About 90% of Dr. Mirza’s patients are female. When she sees PVFM in men, they also tend to have asthma, she noted.
Careful Diagnosis Needed
PVFM is often mistaken for asthma on initial diagnosis, noted Dr. Aviv. The condition may also be confused for lung disease or merely being out of shape, he added.
About 30% of patients with asthma also have some element of paradoxical dysfunction, said Dr. Mirza. However, if patients with asthma are not responding to inhalers as well as they should, she usually suspects PVFM as the primary cause of symptoms.
Physicians and therapists have to be careful when working with this population to make a differential diagnosis, said Dr. Mathers-Schmidt.
Taking a Medical History
Because patients often don’t have any significant PFVM symptoms when they come into the office, Dr. Mirza relies on medical history and clinical suspicion for a diagnosis.
Generally, patients with PVFM often complain of experiencing cough or shortness of breath during exercise, noted Dr. Aviv. PVFM symptoms also tend to occur after an upper respiratory infection. We think a cold or flu has caused vagus nerve injury, leading to shortness of breath, he said.
In addition to taking a medical history, practitioners often observe patients while engaged in the level of activity that tends to induce PVFM, said Dr. Mathers-Schmidt. Many people I’ve worked with experience PFVM as they shift to a higher level of activity, she said. A soccer player could be playing just fine, but once she increases her activity for a fast sprint, she’ll experience PFVM.
Examination and Pulmonary Function Tests
Examination of the vocal folds is another important part of diagnosis. Dr. Mirza often uses flexible laryngoscopy to visualize the vocal folds of patients with suspected exercise-induced PVFM after they have engaged in the physical activity that typically triggers their symptoms.
Dr. Klaben sometimes uses videostroboscopy to examine both vocal folds to see if they are moving correctly and to ensure that no obstruction is present.
Patients with suspected PVFM may also undergo pulmonary function testing. If the condition is present, a truncated flow loop diagram will be produced during inspiration, said Dr. Klaben. The ratio of forced expiratory and inspiratory flow at 50% vital capacity is normally less than 1, but with PVFM, the inspiratory obstruction result in a ratio greater than 1, she explained.
Assessing Reflux
A condition that physicians typically see in conjunction with PVFM is laryngopharyngeal reflux, said Dr. Aviv. He and his colleagues have found that laryngopharyngeal reflux is associated with reduced laryngeal sensitivity, which in turn may trigger PVFM.1 Reflux may also cause some damage to the vagus nerve, which supplies motor impulses to the vocal folds, he said.
Because reflux may contribute to PFVM, asking patients what they have eaten before an episode and examining their posture during increasing physical activity levels is an important part of determining what could be aggravating the condition, said Dr. Mathers-Schmidt.
In addition to reflux, PVFM can worsen with sinusitis and postnasal drip, said Dr. Mirza. Viral infection and chest congestion many also irritate the vocal folds, she said.
Psychological Component to Disease
Practitioners should also take into account that PVFM appears to be associated with an emotional component of being an overachiever, said Dr. Klaben.
High-anxiety situations can trigger an episode, agreed Dr. Mirza, and for athletes, this often means performance anxiety during sporting events.
I worked with a teenager who set very high standards for herself academically and athletically, said Dr. Mathers-Schmidt. The girl was silently talking to herself during sporting events and putting a large amount of pressure on herself to succeed, which in turn, reportedly caused her to tighten her larynx, triggering PVFM episodes.
Moreover, the anxiety that results from breathing difficulty can compound PVFM, said Dr. Klaben.
With visualization, patients actually become aware of what happens to their vocal folds when they breathe in and out and learn to develop better control of their vocal fold movement.
-Natasha Mirza, MD
Treatment of PVFM
While PVFM may be challenging to diagnose, a number of treatment options exist that help the majority of patients overcome the condition.
Dr. Aviv and his colleagues have found that respiratory training in conjunction with management of laryngopharyngeal reflux with proton pump inhibitors is effective for patients with cough and PVFM.2 If patients are not treated for the reflux component, they probably will not experience improvement, he said.
This approach to therapy has a success rate of around 90%, added Dr. Aviv. If patients don’t get better, they probably do not have PFVM, but have a combination of other conditions such as a tumor, vocal fold paralysis, nerve injury, or asthma, he added.
Respiratory training may include inspiratory muscle exercises that make inhaling under controlled conditions difficult, said Dr. Mathers-Schmidt. This teaches patients to breathe optimally against resistance and strengthen their inspiratory muscles. Patients gradually build up muscle strength and learn to maintain an open airway in about five to six weeks, she explained.
Patients are taught to breathe from the diaphragm with a relaxed upper body and shoulder area, alleviating tension in dysrhythmic breathing in the upper thoracic area, added Dr. Klaben. Breathing in through the nose will open the vocal folds to maximal abduction, she said. With athletes, we’ll have them start this type of breathing in a supine position, gradually move them to upright, and then work them on a treadmill or observe them while sprinting, she said.
The therapist may also use biofeedback that allows the patient to view the vocal folds while adducting during inspiration, said Dr. Mirza. With visualization, patients actually become aware of what happens to their vocal folds when they breathe in and out and learn to develop better control of their vocal fold movement, she said.
If the individual is being treated for laryngopharyngeal reflux, diet and behavioral changes, such as not eating prior to sprinting, may also be effective in the control of the condition, said Dr. Klaben.
To address anxiety resulting in excessive laryngeal tension, the speech-language pathologist can help patients combat negative self-talk with cognitive behavioral strategies, said Dr. Mathers-Schmidt. However, some circumstances require a referral to a psychologist, she noted.
Botox injections into the hyperadducting folds may help patients who do not respond to other forms of therapy, added Dr. Mirza. The effect of an injection may last for several months, she noted.
Overall, a multidisciplinary approach to PVFM treatment that includes otolaryngologists, speech pathologists, psychologists, and immunologists, who can address any asthma that might be present, is needed, concluded Dr. Mathers-Schmidt.
References
- Cukier-Blaj S, Bewley A, Aviv JE, Murry T. Paradoxical vocal fold motion: a sensory-motor laryngeal disorder. Laryngoscope 2008;118(2):367-70.
- Murry T, Tabaee A, Owczarzak V, Aviv JE. Respiratory retraining therapy and management of laryngopharyngeal reflux in the treatment of patients with cough and paradoxical vocal fold movement disorder. Ann Otol Rhinol Laryngol 2006;115(10):754-8.
©2009 The Triological Society