How does the larynx work?
The laryngeal muscles receive commands from the branches of the vagus nerve, the main of which is the recurrent laryngeal nerve. On the left, it descends into the chest and goes around the aortic arch, on the right - the subclavian artery, after which it rises back to the larynx along the thyroid gland. This long path makes the nerve vulnerable on many levels. Damage leads to the fact that the fold occupies an intermediate position and does not participate in closure. With a unilateral lesion, a healthy fold partially compensates for the defect; with a bilateral lesion, breathing suffers.
- The recurrent nerve passes through the chest
- The left nerve is longer and more vulnerable
- Involvement at the level of the brain, neck or chest
- Unilateral paresis - voice suffers
- Bilateral paralysis - breathing suffers
- Temporary and permanent form possible
Causes and risk factors
In the first place are surgical interventions in the area where the nerve passes: operations on the thyroid and parathyroid glands, esophagus, chest organs, carotid arteries, and spine from the anterior approach. The second large group is tumors: cancer of the thyroid gland, lung, esophagus, mediastinal lymphoma. The nerve may suffer from aortic aneurysm, left atrium enlargement, after intubation and prolonged ventilation, neck injuries, viral infections, as well as stroke and neurological diseases.
- Surgeries on the thyroid gland and neck
- Surgeries on the chest and esophagus
- Tumors of the lung, thyroid gland, mediastinum
- Aortic aneurysm and heart disease
- Neck injuries and intubation
- Viral infections and neuropathies
- Stroke and diseases of the nervous system
Symptoms
With unilateral damage, the voice becomes weak, quiet, with pronounced aspiration, and quickly becomes exhausted when speaking; the person does not have enough air to speak and has to inhale frequently. Choking when drinking liquids is common, as the larynx protects the airways less well. The cough becomes sluggish and silent. With bilateral paralysis, the voice may remain relatively good, but the folds are close to each other, and noisy labored breathing comes to the fore, increasing with exertion.
- Weak breathy voice
- Fatigue when speaking
- Lack of air to speak
- Choking on liquid
- Silent, ineffective cough
- Noisy breathing in bilateral paralysis
- Shortness of breath on exertion
Diagnostics
First, the very fact of impaired mobility is confirmed: endoscopy of the larynx is performed, assessing the position of the folds during breathing and phonation. Then they must look for the cause along the entire course of the nerve. They do an ultrasound of the thyroid gland and soft tissues of the neck, a computed tomography scan of the chest from the base of the skull to the level of the aorta, and, if necessary, an MRI of the brain. Additionally, thyroid function is assessed and infections and systemic diseases are excluded. If a tumor is suspected, endoscopy of the esophagus is prescribed.
- Endoscopy of the larynx with assessment of mobility of the folds
- Ultrasound of the thyroid gland and neck
- CT scan of the chest along the nerve
- MRI of the brain for neurological symptoms
- Thyroid function assessment
- Endoscopy of the esophagus for suspected tumor
- Assessing swallowing and risk of aspiration
Treatment and recovery
Tactics depend on the cause, duration and side of the lesion. If the nerve is not crossed, recovery is possible within several months, so during this period the underlying disease is treated and classes with a phonopedist are carried out, which help the healthy fold compensate for the defect. For persistent unilateral paralysis, injection of filler into the fold or surgery to shift it to the midline is used, which significantly improves the voice and reduces choking. With bilateral paralysis, the main task is to ensure breathing.
- Treatment of the underlying disease
- Observation and voice rehabilitation for up to a year
- Lessons with a phonopedist
- Injection plasty of the vocal fold
- Surgery to medialize the fold
- Interventions to widen the lumen in bilateral paralysis
- Teaching safe drinking and swallowing
