Vocal Fold Paresis: A Well-Recognized Condition of Ambiguous Significance

When you figure that there are frequently asymmetries in laryngeal motion in the normal larynx, said Dr. Sulica, you begin to appreciate the difficulty in deciding whether a given finding is paresis or not.

Electromyography (EMG) is the only objective way to diagnosis vocal fold paresis, according to Dr. Sulica, and even with the use of this diagnostic tool, mild cases of paresis may be difficult to diagnose. Likening the ability of laryngoscopy to show small asymmetries that are not significant to the ability of electromyography to show nonsignificant small aberrations, Dr. Sulica emphasized that any hypotheses based on the current understanding of paresis are still based on very subjective findings and that more solid evidence is needed to discern which findings are meaningful.

It would be regrettable if vocal fold paresis became the new reflux, he said. Many symptoms that we can’t explain tend to be attributed to laryngopharyngeal reflux without a great deal of critical thinking.

Albert L. Merati, MD, Chief of Laryngology Service in the Department of Otolaryngology-Head and Neck Surgery at the University of Washington Medical Center in Seattle, believes, however, that the majority of laryngeal asymmetries in symptomatic patients are related to changes in the neurologic functioning of the larynx and therefore indicative of paresis. He bases this assertion on a few small studies that reviewed EMG findings in paresis patients (J Voice 2006;20:269-81; Am J Otolaryngol 2006;27:106-8).

His advice to otolaryngologists is to trust their endoscopy. If your patient has a symptom related to the vocal folds and you see an asymmetry by your examination, it is probably real, he said. The real question is what significance does this finding have?

Common symptoms of vocal fold paresis include mild hoarseness, increased phonatory effort, and limitation of pitch-all of which can get more pronounced when a person tries to project his or her voice, or after heavy voice use. Signs include loss of vocal range, soft voice, inability to project the voice, increased vocal roughness, and, sometimes, swallowing problems.

Emphasizing that these are the main symptoms of paresis of the motor nerves, Dr. Sulica also mentioned that other symptoms such as cough, throat clearing, and laryngospasm may indicate the less-explored condition of paresis of the sensory nerves.

Dr. Sulica, however, takes a more cautious approach to diagnosis and emphasizes the need for consistency among the symptoms and signs of paresis with the clinical history of the patient, and recommends electromyography to confirm the clinical suspicion of paresis. I understand very well that these aspects are not always in perfect agreement, he said, so there’s a role for clinical judgment as well.