Partial (paresis) or complete loss (paralysis) of nerve function to voice box muscles results in abnormal vocal fold function, which affects the ability to speak and sing, and in some cases also affect breathing and swallowing functions. Attempts to compensate, oftentimes leads to voice tiring after prolonged use or vocal fatigue.
Temporary or Permanent
Interruption of the nerve input to voice box muscles may be temporary or permanent, partial or complete, affecting one or more voice box muscles.
Vocal fold paresis and paralysis comprise a range - from mild to severe - of abnormal voice box muscle functions due to varying degrees of abnormal nerve input.
A Frequently Missed Cause of Voice Disorders
Paresis of voice box muscles is oftentimes missed as the cause of a voice disorder because patient complaints can be very mild. For example, a patient with vocal fold paresis may only notice voice tiring after use, oftentimes at the end of the day (vocal fatigue).
Identification of Paresis and Paralysis Needs to be Carefully Done
- Absence of vocal fold movement or vocal fold immobility is highly suggestive of vocal fold paralysis but may also be due to other causes - hence thorough medical evaluation is necessary.
- Likewise, if the vocal folds do move, it does not eliminate nerve impairment as a cause of the voice disorder since vocal fold paresis may be present.
Two Key Tests Used To Identify Paresis and Paralysis
- Magnified viewing of vocal movement and position through a special scope or laryngoscopy can identify vocal fold abnormalities suggestive of vocal fold paralysis. (For more information, see Laryngoscopy/Stroboscopy.)
- Laryngeal electromyography or LEMG confirms the diagnosis of vocal fold paralysis and vocal fold paresis. (For more information, see LEMG.)
Identification of Cause
A Key to Treatment Plan
Since there are many causes of vocal fold paresis and paralysis, the cause for each patient needs to be evaluated systematically. As with all disorders, finding out the cause helps map out a treatment plan.
A Treatment Goal
Even when nothing can be done about the nerve damage causing vocal fold paresis or paralysis, improving the function of the vocal fold and voice can be addressed by the voice box surgeon-specialist (laryngologist).
Any and all airway problems require immediate attention.