Dysphonia is a neurologic voice disorder that involves the involuntary movements of one or more muscles of the larynx or voice
box. Typically, the voice will have a tight, strained, or strangled quality. There are three types of spasmodic dysphonia: adductor spasmodic dysphonia, abductor
spasmodic dysphonia, and mixed spasmodic dysphonia. (Watterson, 1992)
are the features of each type of spasmodic dysphonia?
Spasmodic Dysphonia: The most common laryngeal distonia. Sudden involuntary muscle spasms or movements that lead to the slamming
together or stiffening of the vocal folds. Voice sounds strained or strangled,
and speech may sound choppy or as if the individual is stuttering. (Watterson, 1992).
Spasmodic Dysphonia: Involuntary spasms or muscle movements that cause the vocal folds to open. Vocal folds are unable to vibrate and allow air to escape. Voice sounds weak, quiet, and breathy. (Watterson,
Dysphonia: Has features of both adductor and abductor spasmodic dysphonia
Dysphonia: Spasms of the vocal folds during speaking which results in noisy and difficulty taking a breath.
What causes SD?
is not yet known exactly what
however most research
shows that most
of spasmodic dysphonia are
neurogenic and may occur with
other movement disorders. Some research shows spasmodic dysphonia is a result of a problem in the feedback loop between the brain and the larynx.
As recently as the 1970’s, most people thought SD was
in nature. However, research hasincreasingly
that is false. Some believe
spasmodic dysphonia may
be hereditary, and research has
identified a possible gene on chromosome
9 which is common to certain
families that may cause
How is SD diagnosed?
is typically made by a careful examination of the head and neck, and by identifying symptoms.
A team of professionals are used to rule out other pathologies and determine the presence of spasmodic dysphonia. This team includes a Speech-Language pathologist, a Neurologist, and an Otolarynoglogist.
are the treatment options available?
there is no cure for spasmodic dysphonia, however there are treatments to help reduce the symptoms of the disorder. An Otolaryngologist may perform surgery to cut the Recurrent Laryngeal Nerve of the vocal folds to cause
a temporary improvement, or a speech-language pathologist may issue voice therapy to help reduce mild symptoms.
The most common and promising treatment was developed in the late 1980’s that involves
weakening the muscles of the larynx. A very small amount of botulinum toxin (Botox)
is injected into the affected area in order to weaken the muscle and in turn weaken the severity of the spasm of the vocal