The term "laryngeal paralysis" is most commonly associated with animals, specifically dogs and horses. Veterinary medicine recognizes this condition as potentially serious as it can cause interference with breathing to the point of emergency. In humans, a similar condition called laryngeal nerve paralysis, is recognized as causing similar problems. In either case, laryngeal paralysis most simply refers to paralysis of the muscles of the larynx that normally contract and expand during breathing. In other words, the normal function of the larynx is interrupted by the muscles’ inability to function properly.
Laryngeal paralysis in animals is not particularly common, but occurs mostly in larger breed dogs. It can be an inherent condition that affects puppies, but most cases seem to indicate the problem occurring in older dogs for reasons largely unknown. The paralysis can occur gradually over time, posing problems with breathing and panting, and is often indicated by noisy breathing and obvious distress. Ultimately, the animal’s distress in breathing can lead to suffocation if veterinary treatment, which may involve oxygen, sedation, and intubation, is not received. Laryngeal paralysis in animals may or may not be corrected by surgery, and some animals will continue to suffer from an ineffective airway.
In humans, laryngeal nerve paralysis is most often the result of a tumor, cancer of the larynx or a postoperative condition. In the case of postoperative laryngeal paralysis, this condition is associated with thyroid surgery, though is considered an uncommon complication. Patients may have either unilateral or bilateral laryngeal nerve paralysis. Unilateral refers to only one side being affected, while bilateral refers to both. Unilateral laryngeal nerve paralysis, or unilateral vocal fold paralysis, may not be evident immediately and may only present as hoarseness or change in voice, but worsens over a matter of days to weeks. Conversely, the symptoms of bilateral laryngeal nerve paralysis are more immediate and may include respiratory distress or aspiration.
To better understand what happens when part of the larynx suffers from paralysis, one would have to study the anatomy of the larynx. As a part of the respiratory system, the larynx acts as a passageway between the pharynx and the
trachea. More commonly heard of in humans, laryngitis is the
inflammation
of the larynx that results in sore throat, hoarseness or loss of voice, and difficult or painful swallowing. However, the inflammation that is present does not cause the muscles within the larynx to cease to function as with laryngeal paralysis. For more information about this condition in animals, consult your veterinarian. For questions or concerns about the function of the larynx, or symptoms of conditions and diseases of the larynx, consult a physician.