Functional Volume Reduction

Functional dysphonia (FD) is the inability of structurally normal vocal cords to fulfil the appropriate sound production function. In other words, it can be defined as inappropriate or incorrect use of a normal vocal organ. In order to make this diagnosis, the patient must be evaluated in a clinic experienced in voice disorders in the light of all necessary examinations. This patient group constitutes 10-40% of voice disorder patients (1). Although the signs and symptoms of FD may vary greatly, most patients may be seen following upper respiratory tract infection. It is more common in women than men. It is usually transient and the response to treatment is variable.

In FD, various aspects of the voice may be adversely affected. There may be disturbances in voice intensity, pitch or overall quality, and in rare cases the patient may be unable to produce a voice ( Functional aphonia ). Psychological factors and stress can cause the onset or worsening of FD symptoms.

There are many definitions used for or instead of clinical conditions similar to functional dysphonia. These include psychogenic, conversion, hysterical, hyperfunctional, muscle tension and abuse (misuse) dysphonia (2-6).

It is believed that inappropriate contractions of small muscles in the larynx (voice box) play a role in the pathophysiology of functional dysphonia. In various studies, it has been stated that one or more of the following mechanisms may play a role in these contractions (1):

1. Technically incorrect voice use due to the necessity of excessive voice use (2-4)
2. Learned vocal adaptation is required after upper respiratory tract infection (5)
3. Increased tension in the laryngeal and pharyngeal (throat, pharynx) muscles due to voice problems caused by laryngopharyngeal reflux (7,8)
4. Overcorrection of voice problems due to small vocal cord pathologies (such as nodules, polyps) or insufficiencies (9)
5. Excessive tension in the larynx due to personality traits or psychological reasons (10,11)

The diagnosis of FD can be made after a detailed examination of the ear, nose, throat, head and neck region, examination of the larynx by both conventional and current (endoscopic, videolaryngostroboscopic) methods, and other tests (such as voice analysis, diagnostic voice therapy, laryngeal electromyography) to be performed in the voice laboratory when necessary.

If left untreated, FD may adversely affect the quality of life of the person and may lead to organic pathologies (such as vocal cord nodules) if it continues.

The treatment of functional dysphonia is carried out with voice therapy methods that aim to teach the individual appropriate vocal behaviour and apply it in daily life, and various medications used when necessary. Methods that the patient can apply on his/her own to significantly increase the success of treatment include adequate fluid intake, humidification of the breathing air, avoidance of smoking, reduction of general stress, speaking with appropriate voice and breathing support and avoiding the habit of frequent throat clearing (12). Making these precautions a habit is also very useful in preventing recurrence of FD problems.