This disorder related to vocal malfunction can have a sudden or gradual onset (developing over months or years). It can be triggered following an upper respiratory tract infection or as a consequence of the individual's emotional reaction. It can affect notes, vocal pitch and quality, or just a vocal parameter. It can result in aphonia when the cords, very tense, are in an abducted position, or in dysphonia, when they are adducted causing a real disability for the person who has to speak or a simple annoyance. It may be aggravated by medical conditions or as a development of a compensatory response to another underlying problem.
Despite all the labels given to this disorder, one thing is certain: the patient is using his voice incorrectly, specifically he is incorrectly using the muscles responsible for vocal production, creating changes in the acoustic signal.
Common causes are vocal abuse and poor use of the larynx and vocal cords. Some medications, some chronic clinical conditions (e.g. reflux) and exposure to pollutants/irritants contribute to the problem, as do changes in physical-emotional state.
Some professions (teachers, speakers, singers and other voice professionals) and even football fans appear to have a greater risk of developing muscle tension dysphonia due to the high vocal demands.
As previously mentioned, the effects on the voice and larynx can be different and with different severity. These are measured perceptually, acoustically and aerodynamically. The most common vocal signs are: hoarseness, blowing, stridor, peaks and/or pauses in phonation. Speaking softly is sometimes more difficult than speaking loudly.
The most common symptoms related to vocal fatigue are irritation and dryness of the throat, frequent desire to clear the throat.
At the same time there are visible and appreciable signs of excessive muscular tension in the upper triangle and larynx.
Laryngostroboscopic results show a wide range of anomalies ranging from incorrect chordal closure, lateral ventricular and supraglottic compression, antero-posterior compression, chordal width, mucosal wave, closure rhythm, symmetry and periodicity of the vibrational cycles.
Osteopathic treatment for these disorders has been found to be very useful and valid (Liebermann, Carlile) for reducing or eliminating muscle tension dysphonia. Resolution times are related to the chronicity of the problem, the number and complexity of the compensatory schemes triggered, and the onset.