Spasmodic Dysphonia & Vocal Tremor
What is spasmodic dysphonia?
Spasmodic dysphonia (SD) is a focal DYSTONIA (aberrant muscle movement) that is activated only with speech. There are two types of SD; aDductor and aBductor SD.
- ADductor spasmodic dysphonia causes the vocal fold (cords) to have difficulty opening of letting go of a sound during speech resulting in a strained, strangled sounding voice with breaks.
- ABductor spasmodic dysphonia causes difficulty opening the vocal folds which makes it difficult to start the next sound, resulting in a voice with breathy breaks.
- Mixed spasmodic dysphonia is when these two types of SD co-occur
What is tremor?
Tremor is an involuntary, rhythmic contraction of a muscle/s that cause the affected parts of the body to shake. Tremor can be an isolated disorder for example Intention/Essential Tremor or be a symptom of other neurological disorders, for example Parkinson’s Disease. Tremor can be treated with beta-blocking drugs, anti-seizure medications, Botox, tranquilizers or dopamine in the case of Parkinson’s. In some cases, tremor may also be treated with placement of a Deep Brain Stimulator (DBS).
- Vocal Tremor is rhythmic contractions in muscles of voice production resulting in shaking of the vocal mechanism which we hear as shaking in the voice.
Speech-Language Pathology Evaluation
Our Speech-Language Pathologists have specialty training in these conditions.
Assessment will include:
- A detailed history collection
- Laryngeal Function Studies consisting of computerized voice analysis and airway measures
- Behavioral voice and communication analysis
- Tailored assessment techniques to further assess for the presence of these conditions
- Stimuability trials
Treatment
Spasmodic Dysphonia Treatment
- The gold standard treatment for SD is Botox injections into the muscle that experiences the dystonia. This can result in a weak or breathy voice, temporarily. Injections typically need to be repeated every 3 to 6 months.
- Voice therapy is often a part of the overall treatment plan, to maximize healthy vocal function and allow patients to prolong time between injections.
Vocal Tremor Treatment
- Treatment generally consists of medication, if appropriate and / or Botox injections to the vocal mechanism.
- Voice therapy is often a part of the overall treatment plan, to maximize healthy vocal function and allow patients to prolong time between injections.
Additional Information
- National Institute of Neurological Disorders and Stroke:
- National Institute on Deafness and Other Communication Disorders – Spasmodic Dysphonia:
- National Spasmodic Dysphonia Association: