The clinical significance of dynamic laryngeal asymmetry has been a matter of debate. It is likely that there is some biological tolerance for asymmetry in vocal fold movement in contrast to systems like the extraocular muscles in humans, where discoordination carries a functional disadvantage. Altman restricts his discussion to the symptomatic patient, which is a wise qualifier. It is probably useful to attempt to specify symptoms and signs further because many vague examination findings and questionable features of the medical history have been ascribed to mild neurologic impairment of the vocal folds. These include (1) subjective perceptions such as globus and foreign body sensations; (2) poorly defined terms like “voice fatigue,” which can encompass such a breadth of clinical phenomena as to be of dubious utility in clinical discourse; and (3) single, nonrepeated asymmetric motions of the vocal folds. Much of the difficulty likely stems from the fact that signs and symptoms of neurologic dysfunction have been determined by clinical expectations or hypotheses rather than physiologic evidence over most of the history of laryngology, precisely because of a lack of a more objective means of diagnosis like electromyography. Over time and by dint of repetition, some of these have become widely accepted, and the symptomatology of certain types of laryngeal nerve dysfunction—superior laryngeal nerve palsy comes to mind as a particular example—has been confusing and difficult to use as a guide to clinical decision making. Some misconceptions have been corrected by careful research in the laboratory (eg, by Woodson1,2), but ambiguities remain.
Sulica L. LEMG and Laryngeal Asymmetry. Arch Otolaryngol Head Neck Surg. 2005;131(4):359-360. doi:10.1001/archotol.131.4.359-a