Functional Disorders

One of the most common voice disorders we treat is muscle tension dysphonia (MTD). The root word phon means "sound". Phonation refers to the sound made by the voice. The term dysphonia means there is something wrong with the voice. However, muscle tension dysphonia can also refer to a voice that sounds normal, but causes pain, discomfort, or fatigue to the voice user. MTD is known as a functional disorder; that is, there is nothing structurally wrong with the voice. There are no nodules, polyps, paralysis, etc.. Rather, the muscles do not function properly, which causes poor sound, discomfort, or a sensation of increased effort.

Symptoms
Different individuals may have very different symptoms of MTD. In fact, MTD can mimic most structural voice disorders. One feature of MTD is that the voice can be normal sometimes, and very poor at other times. (With structural and neurological disorders, the cause is constant, so the voice is always impaired.)

Possible voice characteristics of MTD

• rough, hoarse, gravely, raspy, coarse
• weak, breathy, airy, leaky, backward, hollow
• strained, pressed, squeezed, tight, tense, choked, effortful
• jerky, shaky, halting
• suddenly cutting out, squeezing shut, breaking off, changing pitch, or fading away
• giving out gradually, or becoming weaker or more tense as voice use continues
• excessively high or low pitch
• inability to produce a loud voice
• inability to produce a clear voice
• inability to sing notes that used to be easy
• running out of breath more quickly than normal

Possible sensations of MTD

• pain or discomfort anywhere in the throat area associated with voice use
• a tight choking sensation associated with voice use
• a sensation of fatigue or effort that increases with voice use
• some area of the neck is tender to the touch
• a feeling of the need to clear the throat frequently
• a feeling of a lump in the throat

Causes
There are many specific, individual reasons why use of the vocal mechanism becomes abnormal. Some general causes are very common:

• prolonged illness
• continued voice use during laryngitis due to illness
• prolonged overuse
• prolonged underuse (such as after a surgery, or even after retirement)
• trauma, such as an injury, chemical exposure, or emotionally traumatic event

These may lead to an abnormal vocal response, causing the individual to compensate by using extra effort while talking.

The onset of MTD can be very subtle. The individual is usually unaware of the extra effort, but this extra effort typically recruits muscles that are not part of the larynx itself. The result may or may not be a stronger voice, but it can be the start of a vicious cycle where more and more effort is required. This cycle may continue for months or even years before the individual becomes aware that his or her voice is abnormal. The reason why some individuals adapt one style of muscle tension over another is unknown.

Treatment
Functional therapy is usually the only treatment available. BUT:

• should only be done after a thorough evaluation by ENT physician
• should be done with a certified speech language pathologist who specializes in voice disorders
• may require only a few sessions, or may take many months for complete relief, but generally some relief is gained within the first 4 to 6 sessions
• in the case of emotional stress, some counseling or stress management may be very helpful or even necessary

Occasionally, medical or surgical treatments may be tried.

• Botox injections may be useful in severe cases
• Surgery to reduce the size of ventricular folds has been tried but is not done at the Lions Voice Clinic
• Muscle relaxants are NOT useful for muscle tension dysphonia - the action of the drugs is not localized to the vocal mechanism, so in order to provide enough relaxation for the vocal mechanism, the individual is often unable to function for day to day living

Types of Muscle Tension Dysphonia
Muscle tension in the vocal mechanism can exhibit itself in many ways. Each individual is different. But here are a few common patterns:

• Anterior-Posterior Constriction
• Hyper Abduction
• Hyper Adduction
• Pharyngeal Constriction
• Ventricular Phonation
• Vocal Fold Bowing

For the purpose of this web site, we have categorized Muscle Tension Dysphonia into these patterns of muscle tension. However, there is not a one-to-one correspondence between the pattern of muscle tension and the sound of the voice or the experience of the individual. Any of the muscle tension patterns can result in a distinct and individual pattern of discomfort and/or poor voice quality. Also, treatment for Muscle Tension Dysphonia is highly individual, and depends more upon how the individual responds to retraining than upon the pattern of muscle tension. Everyone can improve with therapy, but the actual course of therapy varies greatly from person to person and from therapist to therapist.

Muscle tension pattern
The arytenoid cartilages bend forward during voice use, and/or the epiglottis bends backwards, causing the larynx to squeeze from front to back (anterior to posterior). As effort increases, the squeezing continues, causing a vicious cycle. The squeezing in a front-to-back direction may put pressure on the vocal folds such that they bow (see Vocal Fold Bowing), causing poor vibration. In extreme cases, especially in children, the arytenoids may actually vibrate against the epiglottis.

Sound of Voice
Ranges from normal to extremely squeezed and tight sounding. The voice may sound rough if the squeezing causes irregular vibration of the vocal folds. "Froggy" sound if arytenoids and epiglottis vibrate.

Complaints
May include:

• poor voice quality
• discomfort
• pain that increases with voice use but may be constant even during rest
• fatigue and decline of voice quality with voice use

Cause
Prolonged voice overuse, or continued voice use while vocal mechanism is impaired, or prolonged use of a tense style of speaking. Sometimes related to emotional stress. This can also be a normal pattern for the individual, similar to having poor posture; this pattern is seen in many individuals who do not have any voice symptoms.

Treatment:
Functional therapy.

Muscle tension pattern
The vocal folds do not come together to produce voice. They may appear to be pulled apart as the person phonates.

Sound of Voice
Weak, breathy, airy, very soft, hollow, breaks in voicing.

Complaints
Effort and fatigue from voice use; voice is ineffective.

Cause
Sometimes abnormality in vocal mechanism causes pain, leading to protective avoidance of voicing. This can also happen when someone is trying to protect their voice, such as after they had a lesion like nodules. An emotional or stress component is common.

Treatment
Functional therapy, often combined with psychotherapy. Occasionally, injections of a substance to bulk up the vocal folds and provide better closure are helpful as a temporary measure.

Muscle tension pattern
The vocal folds adduct (come together) very tightly, producing a valve that restricts airflow. The larynx may look normal on exam, but the sound and sensation are not.

Sound of Voice
Ranges from normal to extremely tight, pressed, squeezed, strangled, forced or effortful. Tension may be irregular, causing a stopping/starting or shaking effect.

Complaints
May include:

• poor voice quality
• effort and fatigue, usually increasing with continued voice use
• pain
• discomfort

Cause
Prolonged overuse or continued voice use when the vocal mechanism is impaired. Tense style of voice use can cause this pattern of muscle tension dysphonia to become habitual over time. An emotional component may be present.

Treatment
Functional therapy. Occasionally Botox injections are helpful.

Muscle tension pattern
Muscle of the pharynx (throat) contract excessively while talking, leaving the throat very constricted.

Sound of Voice
Ranges from normal to very tight or squeezed, may be tremulous, or may be backward and throaty sounding.

Complaints
May include:

• poor voice quality
• discomfort
• pain that increases with voice use but may be constant even during rest
• fatigue
• decline of voice quality with voice use

Cause
Prolonged voice overuse, or continued use while vocal mechanism is impaired, or prolonged use of a tense style of speaking. Sometimes emotional stress.

Treatment
Functional therapy.

Also called medio-lateral constriction, plica ventricularis, ventricular dysphonia, or false cord phonation.

Muscle tension pattern
The ventricular folds come together and vibrate instead of, or along with, the vocal folds. The ventricular folds, also known as the false vocal cords, are mounds of fleshy tissue just above the true vocal folds. Though the ventricular folds are not muscular, they can be brought together by other muscles (specifically swallowing muscles) and brought into vibration. However, they were not meant to vibrate, so they can't vibrate very fast (for high pitches) or very strongly (for loud sounds). Pressure from the ventricular folds can be strong enough to keep the true vocal folds from vibrating.

Sound of voice
The voice sounds very rough and strained, sometimes not quite human, limited in pitch and volume.

Complaints
May include:

• poor, very abnormal, voice quality
• fatigue, especially with attempts at loud voice use
• pain or dryness with voice use
• sometimes no discomfort at all

Cause
If the true vocal folds are impaired or cannot vibrate for some reason, the ventricular folds may be recruited. Most often, the cause is continued use of voice while true vocal folds are impaired. Sometimes, it could be extreme strain in response to a trauma, including emotional trauma.

Treatment
In extreme cases, medical or surgical treatments may be tried, but only after functional therapy has failed. In some cases, ventricular phonation is the best alternative if the true vocal folds will always be too impaired to vibrate.

Muscle tension pattern
The vocal folds don't come together to vibrate. Instead, they leave a gap, allowing air to leak through.

Sound of Voice
Weak, breathy, hollow, backward, sometimes rough or scratchy. Sometimes there is diplophonia, the sound as if two pitches are being produced at the same time.

Complaints

• Fatigue from voice use
• undependable voice
• sense of effort when talking
• poor volume
• voice gets weaker with continued talking.

Cause
Usually over exertion, sometimes when the individual is in poor condition (vocal fold bowing is sometimes referred to as presbylarynges, which means "the laryngeal status of old age"). This assumes that the vocal folds are bowed because the muscle in the vocal folds has atrophied (wasted away) due to old age. Senior citizens are often told that they must accept their voice quality as a natural part of getting old. Other times, surgery is offered to "plump up" the vocal folds in order to get them to come together again. In the Lions Voice Clinic, we see many individuals of all ages with vocal fold bowing. Also, the senior citizens we see with vocal fold bowing range in voice use from minimal to very heavy voice use. This suggests to us that bowing is not just caused by wasting away of the muscles. We believe it is more often caused by compensatory muscle tension, usually in the anterior-posterior direction, which squeezes the vocal folds apart.

Treatment
In the Lions Voice Clinic, we treat bowing successfully with functional therapy, in a wide variety of individuals. Occasionally a procedure to “plump up” the vocal folds is helpful. There are a number of different options, which we discuss with the patient to find the best possible outcome.