Overview | Understanding the Disorder | Symptoms | Diagnosis | Treatment

Image "A"Key Glossary Terms

Spasmodic Dysphonia (SD)
A voice disorder resulting from involuntary movements (spasms) of the voice box muscles.

A nervous system problem that causes involuntary movement; dystonia is not a psychological problem; SD is a type of dystonia

Adductor SD (Ad-SD)
Spasms in muscles that close vocal folds, which interrupt speech and cause strained or strangled voice breaks

Abductor SD (Ab-SD)
Spasms in muscles that open vocal folds, which interrupt speech and cause breathy or soundless voice breaks


What are the symptoms of SD?

Spasms of the vocal folds cause the typical voice changes of SD – a strained strangled voice for Ad-SD, and breathy voice or soundless breaks in Ab-SD. These are represented below.


  • “Smooth” movement of voice box muscles
  • Fluid voice

Adductor SD

  • “Closure type”: vocal folds come together with too much force, interrupting speech
  • Strained, strangled voice

Abductor SD

  • “Open type”: Vocal folds move apart, interrupting speech
  • Breathy voice or soundless breaks in voice

Mixed Spasmodic Dysphonia: Combination of Symptoms

Patients with mixed SD have voice changes typical of adductor SD and abductor SD.

  • There is no characteristic voice sound for mixed SD, but a careful evaluation of the voice will identify both the strained, strangled voice characteristics of adductor SD and the breathy voice or soundless voice breaks of abductor SD.

Pattern of Symptoms
Severity of Symptoms Varies

  • The severity of the symptoms usually varies from day to day–and even over the course of a single day.
  • Sometimes, voice may be normal, while at other times it is abnormal.

Anxiety Usually Worsens Voice Problem

  • Anxiety or fatigue causes symptoms to be more noticeable.
  • Speaking to strangers, public speaking, or speaking in unaccustomed situations often make symptoms worse, probably because all of these situations increase anxiety.

Telephone Conversations Tough

  • Most people with SD report that using the telephone is especially difficult.

Being Calm Can Improve Symptoms

  • Symptoms are usually mildest in familiar situations.
  • A glass of wine or beer can improve symptoms.

Voice Problems are Task-Specific

SD, like most focal dystonias, is task-specific. Voice problems occur only during specific voice tasks.

  • In the case of SD, this is virtually always conversational speech.
  • The singing voice may remain normal.

Other Symptom Patterns

  • Sometimes, symptoms will disappear in highly emotional situations, such as when the affected person is extremely upset, angry, or laughing.
  • Swallowing and breathing, the other important functions of the larynx, are almost never affected.

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Patient education material presented here does not substitute for medical consultation or examination, nor is this material intended to provide advice on the medical treatment appropriate to any specific circumstances.

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