Spasmodic dysphonia

Spasmodic Dysphonia

Animation of vocal fold movement

Spasmodic dysphonia is a chronic voice disorder characterized by involuntary spasms of the laryngeal muscles, which cause interruptions in speech and affect the voice quality. It is a type of dystonia, a neurological movement disorder.

Types

Spasmodic dysphonia is classified into three main types based on the muscles affected:

Adductor Spasmodic Dysphonia

This is the most common form, where the muscles that bring the vocal folds together (adductors) spasm, causing the voice to sound strained or strangled.

Abductor Spasmodic Dysphonia

In this less common form, the muscles that separate the vocal folds (abductors) spasm, resulting in a breathy or whispery voice.

Mixed Spasmodic Dysphonia

This rare form involves both adductor and abductor spasms, leading to a combination of voice symptoms.

Symptoms

The primary symptom of spasmodic dysphonia is a voice that is interrupted by involuntary muscle movements. This can manifest as:

• Strained or strangled voice
• Breathy or whispery voice
• Intermittent breaks in speech
• Tremor in the voice

Causes

The exact cause of spasmodic dysphonia is unknown, but it is believed to involve abnormal functioning in the basal ganglia, a part of the brain that helps control movement. It may have a genetic component and can be triggered by stress or upper respiratory infections.

Diagnosis

Diagnosis of spasmodic dysphonia is typically made by a team of specialists, including an otolaryngologist, a neurologist, and a speech-language pathologist. The evaluation may include:

• Laryngoscopy to visualize the vocal folds
• Voice analysis
• Neurological examination

Treatment

There is no cure for spasmodic dysphonia, but several treatments can help manage the symptoms:

Botulinum Toxin Injections

Botulinum toxin injections into the affected muscles are the most common treatment, providing temporary relief by weakening the muscles and reducing spasms.

Voice Therapy

Voice therapy with a speech-language pathologist can help patients develop strategies to improve voice control and reduce strain.

Surgery

In some cases, surgical interventions such as selective laryngeal denervation-reinnervation may be considered.

Prognosis

Spasmodic dysphonia is a chronic condition that can significantly impact quality of life. While treatments can help manage symptoms, ongoing therapy is often necessary.

Related pages

• Dystonia
• Larynx
• Voice therapy