What is
spasmodic dysphonia?
Spasmodic dysphonia, also called laryngeal dystonia, is
a voice disorder. It is characterized by involuntary spasms
or movements in the muscles of the larynx, which causes
the voice to break, and have a tight, strained, or strangled
sound.
Difficulties that result from spasmodic dysphonia range
from occasional problems with saying a word or two to complete
inability to communicate.
Spasmodic dysphonia most often affects women, particularly
between the ages of 30 and 50.
What are the different types of spasmodic dysphonia?
There are three types of spasmodic dysphonia:
• adductor spasmodic
dysphonia
Characterized
by sudden involuntary spasms that cause the vocal cords
to slam together
and stiffen. The spasms interfere with vibration of the
vocal cords and
production of sound is difficult. Stress can make spasms
more severe.
Speech sounds
are strained and full of effort. Spasms do not occur when
whispering,
laughing, singing, speaking at a high pitch, or speaking
while breathing
in.
• abductor spasmodic dysphonia
Characterized
by sudden involuntary spasms that cause the vocal cords
to open. Vibration
cannot occur when cords are open so production of sound
is difficult. Also, the open position allows air to escape
during speech.
Speech sounds
are weak, quiet, and whispery. Spasms do not occur when
laughing or singing.
• mixed spasmodic
dysphonia
Characterized
by symptoms of both adductor and abductor spasmodic dysphonia.
What causes spasmodic dysphonia?
The exact cause of spasmodic dysphonia is not known. Most
cases are believed to be caused by a nervous system disorder,
and may occur with other movement disorders. Spasmodic
dysphonia may be a genetic disorder, or may begin following
an upper respiratory infection, injury to the larynx,
a long period of voice use, or stress.
How is spasmodic dysphonia diagnosed?
In addition to a complete medical history and physical
examination, examination of the vocal folds by fiberoptic
nasolaryngoscopy may be performed. This procedure involves
using a lighted tube, passed though the nose into the
larynx to evaluate movement of the vocal folds during
speech.
Treatment for spasmodic dysphonia:
Specific treatment will be determined by the physician(s)
based on:
• patient's age, overall
health, and medical history
• extent of the disease
• expectations for
the course of the disease
• patient's tolerance
for specific medications, procedures, or therapies
• patient's opinion
or preference
The goal of treatment is to reduce symptoms of the disorder.
Surgery to cut one of the nerves of the vocal fold has
been used, as well as counseling. Some success has been
achieved with the injection of the botulinum toxin directly
into the affected muscles of the larynx.
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Voice and Speech
Speech is a complex process
that starts with muscle movement, which involves:
• phonation
(voice)
•
respiration (breathing process)
• articulation (throat,
palate, tongue, lips, and teeth)
These muscle movements are initiated, coordinated,
and controlled by the brain, and monitored through
hearing and touch.
Voice production, or phonation, is generating and
modulating sound as part of the speech process.
Voice is created in the vocal cords (or vocal folds)
of the larynx.
The larynx, often referred to as the voice
box, is a two-inch long tube-shaped organ
located in the neck at the top of the trachea (windpipe).
The cartilage in front of the larynx is sometimes
called the "Adam's apple."
The vocal cords (or vocal folds) are two bands of
muscle that form a "V" shape inside the
larynx.
The area of the larynx where the vocal cords are located
is called the glottis. The area above the cords is
called the supraglottis, and the area below the cords
is called the subglottis. The epiglottis is a flap
at the top of the trachea that closes over the larynx
to protect it from food that is swallowed into the
esophagus.
Breath enters the body through the nose or mouth,
and then travels to the larynx, trachea, and into
the lungs. It exits along the same path. Normally,
no sound is made by the vocal cords during breathing
or exhaling.
When a person talks, the vocal cords tighten, move
closer together, and air from the lungs is forced
between them. This makes them vibrate and produces
sound.
Source: National Institute on Deafness and Other Communication
Disorders
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