Hoarseness

What are the symptoms of vocal fold disease?

Paralysis of the vocal fold muscles can manifest itself in very different ways.

Paralysis of the vocal fold muscles can manifest itself in very different ways. The most common symptom of unilateral vocal fold paralysis is hoarseness. The voice sounds a little hoarse and raspy. Speaking is also much more strenuous for the patient, as an excessive amount of air is exhaled. This is because vocal fold paralysis is also accompanied by a lack of glottal closure. However, complete vocal fold closure is important for speech. When speaking, the normal speaking voice is produced in such a way that – similar to a woodwind instrument – a large amount of air pressure is required to produce the normal speaking voice. If the glottis is too wide, much more air than usual is passed through the glottal slit. As a result, those affected experience voice fatigue much more quickly after speaking for a long time. Respiratory problems can also be present in vocal fold paralysis. Too little air on exertion, noisy breathing (stridor) and ineffective or weak coughing. Another symptom of vocal fold paralysis is diplophonia. This means that the voice sounds as if it were gurgling. It is not uncommon for vocal fold paralysis to cause swallowing problems. Swallowing food, drinks or even saliva can then cause coughing.

What is vocal fold paresis?

The paralysis (paresis) of the vocal folds results from incorrect nerve signals to the muscles of the larynx (laryngeal muscle). Vocal fold paralysis can affect you at any age, from birth to old age. Women and men are equally affected, and the causes are manifold. The impact on those affected varies and depends on their occupation. A weak vocal cord paralysis can mean the end of a singer’s career, but has virtually no effect on the work of a programmer.

What are the causes of vocal fold paralysis?

The causes of the paralysis can indicate whether the dysfunction is only temporary or permanent. If the cause is reversible, surgical treatment is usually not recommended due to the likelihood of a quick recovery. Despite advances in diagnostic techniques, in half of all cases of vocal cord paralysis, specialists are unable to identify the cause. Due to the unknown cause, these cases are referred to as “idiopathic”. In idiopathic vocal fold paralysis, the disease could be the result of viral infections of the laryngeal nerves (recurrent laryngeal nerve and superior laryngeal nerve) or the vagus nerve, although this cannot be proven in most cases. Known causes of the disease are

(1) Viral infections: Inflammation caused by viruses could spread to the vagus nerve or its branches to the larynx (recurrent laryngeal nerve and superior laryngeal nerve) and injure them. Systemic diseases – i.e. diseases that affect the entire organism and impair the nerves in the body – can also affect the laryngeal nerves.
(2) Tumors of the skull base, neck and chest: Tumors, whether benign or malignant, can grow around the nerves and exert pressure on the nerves. This can lead to various types of paralysis.
(3) Accidental injury during the operation: Operations in the neck or chest area could unintentionally result in recurrent nerve palsy (paralysis of the recurrent laryngeal nerve). Recurrent paresis can generally occur during operations in the head, at the base of the skull and on the side of the neck.
(4) Complications of endotracheal intubation: Recurrent nerve injuries can also occur when the breathing tubes (intubation tubes) are used for anesthesia and/or artificial respiration. However, this type of injury is rare, given the frequency of operations under anesthesia.
(5) Blunt neck or chest trauma: Any type of deep, hard impact to the neck and chest area could injure the recurrent laryngeal nerve. Very strong impacts and blows to the neck, for example after accidents, can also injure the recurrent laryngeal nerve.

Which nerves are affected by vocal fold paresis?

The movements of the vocal folds are the result of coordinated contractions of various muscles. These are controlled by the brain through certain nerves. The following nerves receive signals:

The superior laryngeal nerve, which transmits the signals to the cricothyroid muscle, is located between the cricoid cartilage and the thyroid cartilage. As the cricothyroid muscle determines the tension of the vocal cords for high notes during singing, paralysis of the superior laryngeal nerve results in a change in vocal pitch and can cause problems when singing, which are particularly noticeable when intoning higher notes with a soft transition. In some cases, patients with vocal fold paralysis can speak normally but only sing with distortion.

The recurrent laryngeal nerve (Nervus laryngeus recurrens) transports signals to the laryngeal muscles, which open and close the vocal folds when breathing or coughing, so that the vocal cords vibrate and speech can be produced. The recurrent laryngeal nerve is also important for the swallowing function. The recurrent laryngeal nerve runs from the neck down into the chest cavity and from there back into the neck to the larynx. Due to its length and because it is connected to the larynx via a “detour”, there are many reasons for injuries. Infections and tumors of the brain, neck, chest or larynx, as well as complications from operations in the head, neck or chest can injure, stretch or put pressure on the nerve. Consequently, the recurrent laryngeal nerve is involved in most cases of vocal cord paralysis and paresis. As the recurrent laryngeal nerve is the only nerve that supplies the internal laryngeal muscles for vocal cord opening, paralysis of a recurrent laryngeal nerve leads in particular to vocal fold arrest. The vocal fold is then almost in the midline. This is noticeable in the patient through hoarseness.

How is vocal fold paralysis diagnosed?

The ENT specialist will carry out a full examination and then question you about your symptoms and lifestyle (voice use, alcohol/tobacco consumption). The examination of the larynx is carried out to determine whether one or both vocal cords (vocal folds) are affected. Determining this is important for further treatment. However, further investigations may also be necessary, as there is a very long list of diseases that can result in nerve damage. These tests include blood tests, X-rays, CT scans, MRIs and endoscopic examinations under anesthesia.

What treatment options are there for the vocal folds?

The two treatment strategies to improve speech function are voice therapy, the equivalent of physical therapy for large muscle paralysis, and phonosurgery, a procedure in which the vocal cords are repositioned and trimmed to improve vocal function. Voice therapy is usually the first step in treatment. Once this therapy has been completed, the decision on surgical intervention is made depending on the severity of the symptoms, the patient’s voice requirements, the position of the paralyzed vocal cords, the prospect of recovery and the cause of the paralysis.
In principle, any hoarseness that lasts longer than four weeks should be clarified by an ENT specialist.