Mr Malcolm Baxter (ENT surgeon) and A/Prof Sanjay Raghav(Neurologist) are doing Voice clinic for Spasmodic Dysphonia and similar disorders for more than 10 years.
Maybe you have heard someone whose voice sounds tight, strangled, broken, whispery, or otherwise “not quite right.” It may be your own voice or that of someone you know. You may be trying to determine what is wrong, or a doctor may have already diagnosed the condition as Spasmodic Dysphonia (SD) or Laryngeal Dystonia.
Spasmodic dysphonia belongs to a family of neurological disorders called dystonias. A dystonia is a movement disorder that causes muscles to contract and spasm involuntarily. Dystonias can be generalized, affecting the entire body, or focal, affecting only a specific area of the body or group of muscles.
Following Parkinson’s disease and essential tremor, dystonia is the third most common movement disorder. The most common focal dystonia, cervical dystonia, causes the neck to twist or contort. Other dystonias can cause abnormal, involuntary blinking or spasm of the eyelids (blepharospasm), inappropriate contractions of the hand muscles (writer’s cramp), or uncontrolled movements from spasms in any of the muscles of the face, jaw, or tongue (oromandibular dystonia).
Certain dystonias, including SD, are task-specific, meaning that the muscles spasm only when they are used for particular actions and not when they are at rest. When a person with SD attempts to speak, involuntary spasms in the tiny muscles of the larynx cause the voice to break up, or sound strained, tight, strangled, breathy, or whispery. The spasms often interrupt the sound, squeezing the voice to nothing in the middle of a sentence, or dropping it to a whisper. However, during other activities, such as breathing and swallowing, the larynx functions normally.
Spasmodic dysphonia is estimated to affect approximately 10 Million people worldwide, but this number may be somewhat inaccurate due to ongoing misdiagnosis or undiagnosed cases of the disorder. Although it can start at any time during life, SD seems to begin more often when people are middle-aged. The disorder affects women more often than men. Onset is usually gradual with no obvious explanation. Symptoms usually occur in the absence of any structural abnormality of the larynx, such as nodules, polyps, carcinogens, or inflammation. People have described their symptoms as worsening over an approximate 18-month period and then remaining stable in severity from that point onward. Some people have reported brief periods of remission, however this is very rare and the symptoms usually return.
Diagnosing Spasmodic Dysphonia is difficult since the voice can vary significantly and the symptoms can present very similarly to other conditions such as Voice Tremor or Muscular Tension Dysphonia (a very common voice problem). This can lead to increased frustration and anxiety in the person with the condition and delays in accessing effective treatment. Initially you will be assessed by team of ENT surgeon, Mr Malcolm Baxter and Movement Disorder Specialist A/Prof Sanjay Raghav for Stroboscopy & neurological examination and then, if appropriate, for treatment with Botulinum toxin injections
Oral medications include benzodiazepines which act as muscle relaxants, anticholinergics and anti-epileptic drugs. These medications have been used with limited success.
Botulinum toxin remains the treatment of choice for most people with spasmodic dysphonia. Extremely small amounts of this widely used and clinically safe substance are injected into the affected laryngeal muscles, which reduces the overactivity of the muscles by weakening them.
It can provide significant (although temporary) relief from symptoms and marked improvement in voice quality. Botox acts by weakening the overactive muscles for approximately two to six months, after which further injections are needed throughout the person’s life.
There are possible initial side effects such as mild swallowing difficulties or a weak voice but for most it is well tolerated. Where the pharynx, palate and tongue are involved Botulinum toxin is not so successful.
In many cases, a trial of voice therapy with a speech pathologist is also offered prior to or with Botulinum toxin.
Surgery: there have been many surgical procedures performed for SD with varying success.
These include surgical separation of the vocal cords (thyroplasty) and various other procedures to cut part of the nervous supply to the muscles of the larynx.
A Speech Pathologist can assess the type of dysphonia and teach strategies to improve voice production and projection as well as giving advice on any swallowing difficulties.
Alternative therapies: if you are considering alternative therapies you should discuss them with your specialist beforehand to ensure they are not contraindicated in your condition.
Voice tremor is a neurological disorder that causes a regular wavering of the voice, not unlike an exaggerated singer’s vibrato, except that it occurs during speech as well as during singing. This disorder is one subtype of a neurological disorder called essential tremor, and it should be distinguished from another neurological disorder that sometimes includes a tremor component and consequent wavering in the voice laryngeal dystonia. Sometimes Botulinum toxin can help in this condition as well along with voice therapy.
Link for Spasmodic Dysphonia Video: