Vocal cord palsy

definition

The term vocal cord paresis describes paralysis of the muscles that move the vocal cords in the larynx. The result is that the vocal folds, which are set up in pairs, are restricted in their movement and thus speaking and possibly breathing are difficult. There are a number of small muscles in the larynx that help move and tension the vocal cords. If the nerves that control these muscles are damaged, vocal cord paresis occurs. This can occur unilaterally and bilaterally, with bilateral vocal cord paresis being an emergency due to the obstruction of the airways.

causes

The causes of vocal cord paresis can be very diverse. What they all have in common is that as a result nerve supply the muscles involved is disturbed. Run as the most common causes direct nerve damage to a vocal cord paresis. The affected nerve is the Recurrent laryngeal nerve (short: recurrent nerve), which is present on both sides and controls almost all larynx muscles on one side. During surgical interventions on the thyroid or the Carotid artery this nerve can be injured because of the close anatomical relationships, resulting in a so-called Recurrent palsy results. Therefore, this complication is always pointed out before such operations.
Other operations on the neck such as for the treatment of tumor diseases on the larynx or in the esophagus can damage the nerve. The tumor itself can also cause vocal cord paresis. Another cause of vocal cord palsy is one Bulging of blood vessels, Aneurysm called. On the carotid artery or the aorta located, these can irritate the recurrence.In addition, any injuries or trauma in the neck area are possible causes of vocal cord paresis. In addition, as part of a Stroke Areas of the brain that control the larynx may be affected. In rare cases, inflammation and viral diseases have been observed as causes of vocal cord paresis

Symptoms

Vocal cord palsy causes a number of typical symptoms. For the proper formation of the language that is complete closure of the vocal folds necessary, which is not possible with vocal cord paresis. The leading symptom is hoarseness, which occurs in unilateral vocal cord paralysis, which is more common than bilateral. One side of the vocal folds function normally, while the other is paralyzed and does not resonate properly with voice formation. This causes a hoarseness that can be both mild and very pronounced.

In the bilateral vocal cord paresis speaking is actually not possible. The bigger problem, however, is that the airways can be severely narrowed or even obstructed by the paralysis on both sides, which is too massive Shortness of breath can lead.

Diagnosis

A detailed questioning of the patient is often sufficient for the diagnosis of vocal cord paresis. Are of particular interest Previous operations on the neck and some of them very much pronounced hoarseness. The ENT doctor can then do a Larynxoscopy during which the movement and position of the vocal folds can be assessed. To the Exclusion of throat cancer Computed tomography (CT) or magnetic resonance imaging (MRI) may be useful.

Paramedian position

A term from the diagnosis of vocal cord paresis that is often used is the so-called Paramedian position. The term paramedian position describes the position of the vocal cords in the context of a vocal cord paresis, in which the closure of the vocal cords is not entirely possible and one side comes to lie slightly next to (para) the middle (median). This is a clear indication of a Damage to the recurrent laryngeal nerve. The paramedic position can be seen during laryngoscopy and is important in the differential diagnosis of vocal cord paresis, since other positions of the vocal folds such as the intermediate position (central) or lateral position (side) indicate other disorders.

left vocal cord paresis

Vocal cord paresis can occur on both sides or on one side. It occurs on the left when a surgical intervention was made on the left neck or a tumor infiltrated the left recurrent nerve. A special feature of left vocal cord paresis is that the nerve on the left has a slightly different course than on the right. He pulls down here deeper under the aortic archso that on this side also bulges or tears of the aortic arch, like a Aortic aneurysm can cause left vocal cord paresis. Likewise, processes in the lung affect the nerve on the left.

right-sided vocal cord paresis

On the right side, the course of the extends N. laryngeus recurrens nothing all the way into the rib cage, so the chances of affecting the nerve are slightly less than on the left side. aorta and lungs are not in contact with the nerve on the right. Of course, all processes, interventions and injuries on the neck can affect the nerves. If there is unilateral vocal cord paresis, the symptoms can be observed largely regardless of whether the damage is on the left or right.

therapy

If there is vocal cord paresis, the therapy initially depends on the cause. The goal is always to bring the vocal folds back together as closely as possible. For example, compression of the recurrent nerve by a Tumor or aneurysm the cause of vocal cord paresis, therapy consists in the Removal of these restrictive processes. Often the vocal cord palsy recovers over time.
If the nerve was injured during an intervention or if there is irreversible paralysis, further therapy measures must be initiated. The plays a major role in this Speech therapy, which almost every patient with vocal cord paresis uses. The language is improved here with special exercises. If this is not successful either, a invasive therapy be useful. Special substances can be injected under the affected side of the vocal fold to bring it closer to the center. There are also operative techniques in which with the help of a stamp (Thyreoplasty according to Isshiki) one side pushed further towards the middle or with seams (Arytenoid adduction) is pulled in that direction. These methods are at the unilateral vocal cord paresis makes sense.
The rare bilateral paralysis of the vocal folds may require one in an emergency Tracheal incisionTo avoid suffocation, in the course of a Expansion of the vocal folds become necessary.

Speech therapy

In most cases of vocal cord paresis, speech therapy is an important pillar of treatment. With the help of special exercises, under professional guidance from the speech therapist, the patient can train his vocal folds to such an extent that a clear improvement of the voice is possible, up to and including complete recovery. Speech therapy for vocal cord paresis is particularly promising when the nerve has not been completely severed. The goals of speech therapy are to stimulate the muscles in the larynx and prevent wasting away, as well as to train the healthy side of the vocal folds beyond the normal range so that it extends over the middle to the paralyzed side. Normal speech can be generated by closing the glottis

Duration

It is difficult to give a general indication of the duration of a vocal cord paresis because it depends on the root cause, the Extent of damage and the Type of treatment depends. The vocal cord paresis treated with speech therapy should be significantly improved within one to one and a half years. If the constriction that was removed was the cause, it may only last a few months if the nerve has not been severed. In some cases, however, a certain life-time Hoarseness and restriction of speech exist.