Spasmodic Dysphonia

by , last modified on 4/13/21.


Spasmodic dysphonia is a type of dystonia in which there are involuntary muscle spasms or contractions of the muscles involved in voice production. This disorder is similar to the involuntary eyelid twitches of blepharospasm. Spasmodic dysphonia should not be, but is often confused with muscle tension dysphonia or tremor. There are generally 2 types of spasmodic dysphonia: ABductor and ADductor (Listen to samples or video on this topic).

ADductor dysphonia is when the vocal cords comes together suddenly while talking resulting in voice stops and effortful speech. Often, the voice chokes off. Counting from 80 to 89 is harder than counting from 60 to 69. Stressful situations often exacerbate the condition. ABductor dysphonia is when the vocal cords suddenly moves apart while talking resulting in loss of voice (breathy). These patients find counting from 60 to 69 harder than counting from 80 to 89.

ABductor dysphonia is not as common as ADductor dysphonia. Other difficult phrasing tasks are listed below.

Difficult Phrases for ADductor Spasmodic Dysphonia
Difficult Phrases for ABductor Spasmodic Dysphonia
Counting from 80 to 89
Counting from 60 to 69
"We mow our lawn all year."
"Peter will keep at the peak."
"We eat eels every day."
"The puppy bit the tape."
"A dog dug a new bone."
"When he comes home, we'll feed him."
"Where were you one year ago?"
"Tap the tip of the cap, please."
"We rode along Rhode Island Avenue."
"Keep Tom at the party."
"Eeee eee eee."
"See see see."

Below this paragraph are audio clips of 2 patients with ADductor spasmodic dysphonia. The first clip is a reading passage where one can hear a mild waver to her voice. The second clip is when she tries to speak all of the "difficult phrases" for ADductor spasmodic dysphonia which accentuates the voice-weighted aspects of the words known to trigger spasms resulting in vocal fluency loss. As expected, she did much better vocalizing the difficult phrases for ABductor spasmodic dysphonia in the 3rd audio clip which accentuates voiceless weighted words which minimize spasms. If she had ABductor spasmodic dysphonia, the reverse would have been true. The last audio clip is of a different patient with a severe case of ADductor spasmodic dysphonia

Mild case of ADductor spasmodic dysphonia
Standard Passage (note very mild loss of vocal fluency)
ADductor Passages (note the vocal quality is less fluent)
ABductor Passages (note the improved fluency)
Severe case of ADductor spasmodic dysphonia Standard Passage

Treatment with BOTOX

There have been many different treatment modalities developed to try and address spasmodic dysphonia including voice therapy, surgery, as well as BOTOX injections. Only BOTOX has been found to be consistently helpful. I personally feel that voice therapy is a useful adjunct to BOTOX injections, but typically ineffective by itself.

Spasmodic dysphonia is treated by injecting BOTOX into the affected muscles of the voicebox. BOTOX is currently considered the standard of care. BOTOX injection is accomplished under EMG guidance through a space between the voicebox and top of the windpipe (cricothyroid space). There are different techniques to inject BOTOX. The way Dr. Chang performs this procedure is with the patient sitting up in a chair after the area is numbed with local anesthetic for patient comfort.

The whole process takes less than 5 minutes to perform. A video demonstrating the technique I use to inject BOTOX is shown below as well as here.

The amount of BOTOX injected is unique to each patient and there is no such thing as standard injection amount to produce relief. Generally speaking, most patients require between 0.8 and 2 units of BOTOX to each side for affect. The amount is titrated at each visit until the precise amount that works for a given patient is found. This may take around 3 treatments before the appropriate amount is figured out.

As BOTOX lasts only around 3 months (though in rare case, may last as long as 6 months), repeat injections are necessary. However, generally speaking, the duration of relief may last slightly shorter with smaller amounts and longer with larger amounts of BOTOX injected.

Side Effects With BOTOX Treatment

There are side effects. In fact, if there are no side effects, the BOTOX injection either didn't work, or the beneficial effects will last for only a very short time. Usually after an injection for a patient with ADductor type spasmodic dysphonia, the patient has a "Mickey-Mouse" breathy voice for about 1 week, though it can last as long as 4 weeks. Patients with ABductor type will have side effects of shortness of breath and a "tight" sounding voice for a similar time period. There may be problems swallowing for both types, though not severe. Voice normalization occurs after this period. Occasionally, there may not appear to be any change and repeat injection may be needed earlier than usual.

KEY POINT! Generally speaking, a large dose of BOTOX injected will result in longer-lasting relief, BUT the side effects are more severe and longer-lasting as well (though always resolve). Smaller amounts of BOTOX injected minimizes the side effects, but relief would last for a shorter period of time requiring more injections per year. The goal is to find the right balance of side effect duration and normal voice duration. For most people, 1 week of side effects with 3 months of normal voice duration provides the perfect balance between side effects and duration of normal voice.

Factors to Consider With BOTOX Treatment

There are many factors to consider when deciding what the appropriate amount of BOTOX to inject is. If one is a voice professional, it may be important to have a good voice with minimal side effects. This person may elect to go with smaller BOTOX injection amounts to minimize side effects understanding that more injections may be needed in a given year compared to another person who feels it more important to minimize the number of trips to the doctor and therefore elects to go with a larger BOTOX amount with the understanding that side effects may be significant for a longer period of time.

Another factor to consider is insurance. Though all insurance companies cover this treatment, some insurance companies will pay for only a certain maximum number of injections per year. Check with your insurance company to see if this applies to you. For those who are uninsured or otherwise unable to afford treatment, click here.

BOTOX injections for SD and other forms of head & neck dystonias are performed every Friday afternoon by Dr. Chang after an initial patient evaluation.

For more information on this disorder, check out the information at NIDCD and NSDA.

Surgical and Other Treatment Options for Spasmodic Dysphonia

Though BOTOX is the standard of care and most commonly performed treatment for spasmodic dysphonia, there are new surgical options being developed including DeRe, Myectomy, and Thyroplasty. Dr. G. Berke at UCLA offers DeRe and has had good results. However, long-term (5-10 years out) results are unknown and any complications are permanent. Dr. J. Koufman in New York City offers thyroarytenoid myectomy, but less than a dozen patients have undergone this procedure (published in the literature) and results beyond a few years are unknown.

Some have tried voice therapy which does prolong the effects of BOTOX injections. However, it has limited utility by itself with individuals having great difficulty translating therapy exercises into daily social conversation. Also, one has to constantly work at it. As such, I consider speech therapy to be only an adjunctive treatment to BOTOX injections.

Financial Assistance

Reimbursement assistance for those who are uninsured or otherwise unable to afford BOTOX can be found here ( Or call 1-800-44-BOTOX, option 6. The form you will be required to complete can be downloaded here. The ICD-9 code to be stated for coverage should be 333.83. ICD-9 478.75 will be denied.

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Christopher Y. Chang, Chabot P, Thomas JP. Relationship of Botulinum Dosage to Duration of Side Effects and Normal Voice in Adductor Spasmodic Dysphonia. Otolaryngology-Head & Neck Surgery. 136(6):894-899, 2007. Link

Christopher Y. Chang, Chabot P, Thomas JP. Chapter: Age as a Factor in Responses to Botulinum Toxin Injection in Adductor Spasmodic Dysphonia Patients. Laryngeal Diseases. Nova Science Publishers, 2010. ISBN:978-1-60876-107-4. Link

Christopher Y. Chang, Chabot P, Walz CM. Current Practices of Physicians Treating Adductor Spasmodic Dysphonia in the United States. ENT Journal. 88(5):Online, 2009. PMID: 19444777

Books describing voice therapy techniques to address spasmodic dysphonia:

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