Gal Levy, M.Sc., CCC-SLP | Article

Spasmodic Dysphonia (SD) or “Stuttering of the Vocal Cords”.

This article will shed some light on:

Spasmodic Dysphonia (SD) or “stuttering of the vocal cords”.

What is SD?

Laryngeal Dystonia or as it called Spasmodic Dysphonia is an organic voice
disorder caused by dysfunction of center neurological integration
that produces spasm of the vocal cords. Spasmodic dysphonia causes
the voice to break or to have a tight, strained or strangled quality.
There are three different types of spasmodic dysphonia: adductor
spasmodic dysphonia (closed glottis), abductor spasmodic dysphonia
(open glottis) and mixed spasmodic dysphonia.

In adductor spasmodic dysphonia, sudden involuntary muscle movements or
spasms cause the vocal cords to slam together and stiffen. By that
make it difficult for the them to vibrate and produce voice. Words
are often cut off or difficult to start, speech may be choppy and
sound similar to stuttering. The voice is commonly described as
strained or strangled and full of effort.

Mixed spasmodic dysphonia involves muscles that open the vocal folds as well as
muscles that close the vocal folds and therefore has mixed features
of both above – mentioned syndromes.

Surprisingly, all 3 conditions are usually absent while doing vegetative phonation,
whispering, crying, laughing, singing, speaking at a high pitch
,speaking when just woke up from a sound sleep or after drinking
alcoholic beverages ( SD is the only
voice disorder for which I am allowing my patients to drink some
alcohol!) As in many other voice disorders, Stress and nervousness,
will make the muscle spasms even more severe.

SD is another mysterious voice disorder, the cause is yet unknown.
Because the voice can sound normal at times, spasmodic dysphonia was
once thought to be psychogenic, but as reported by NIDCD ( The
National Institute of Deafness and other Communication Disorders),
research has revealed increasing evidence that most cases of
spasmodic dysphonia are in fact neurogenic and may co-occur with
other movement disorders such as blepharospasm (excessive eye
blinking and involuntary forced eye closure), tardive dyskinesia
(involuntary and repetitious movement of muscles of the face, body,
arms and legs), oromandibular dystonia (involuntary movements of the
jaw muscles, lips and tongue), torticollis (involuntary movements of
the neck muscles), or tremor (rhythmic, quivering muscle movements).

NIDCD also reports that spasmodic dysphonia may run in families and is thought to be
inherited. Research has identified a possible gene on chromosome 9
that may contribute to the spasmodic dysphonia that is common to
certain families. Spasmodic dysphonia can affect anyone between 30
and 50 years of age. More women appear to be affected by spasmodic
dysphonia than are men.

Treatment for SD?
The “triangle” ENT –Neurologist – SLP is usually on the front line in diagnosing
and treating the symptoms of SD. There is presently no known cure for
spasmodic dysphonia. Current treatments only help reduce the

SLP- Voice therapy may reduce some symptoms, especially in mild cases. Voice Therapy and
Vocal Cords special physiotherapy may also support a better voice
while undergoing the post effects of treatment of choice – see

ENT- has 2 common options, One: an operation that cuts one of the nerves of the vocal
folds (the recurrent laryngeal nerve) thus improving the voice for
several months to several years.

Two: injections of very small amounts of botulinum toxin (botox) directly into the
affected muscles of the larynx. Botulinum toxin is produced by the
Clostridium botulinum bacteria. This is the bacterium that occurs in improperly canned
foods and honey. The toxin weakens muscles by blocking the nerve
impulse to the muscle. The botox injections generally improve the
voice for a period of three to four months after which the voice
symptoms gradually return. Reinjections are necessary to maintain a
good speaking voice. Initial side effects that usually subside after
a few days to a few weeks may include a temporary weak, breathy voice
or occasional swallowing difficulties – this will be the best time
to refer the patient to speech therapy , as was mentioned above.
Botox may relieve the symptoms of both adductor and abductor
spasmodic dysphonia, and is considered to be the main line of defense
against SD.