Adductor Spasmodic Dysphonia

Adductor Spasmodic Dysphonia

Adductor Spasmodic Dysphonia (ADSD) is a neurological voice disorder characterized by involuntary spasms of the vocal cords during speech. These spasms cause the vocal cords to close tightly, resulting in a strained, strangled voice quality. ADSD is the most common form of spasmodic dysphonia, a group of disorders affecting the laryngeal muscles.

Pathophysiology

ADSD is believed to be a focal dystonia, a type of movement disorder that affects specific muscles. The exact cause of ADSD is not fully understood, but it is thought to involve abnormal functioning of the basal ganglia, a group of structures in the brain that help control movement. The spasms in ADSD specifically affect the adductor muscles of the vocal cords, which are responsible for bringing the vocal cords together during speech.

Symptoms

The primary symptom of ADSD is a voice that sounds strained or strangled. Patients may also experience:

• Intermittent breaks in the voice
• Effortful speech
• Vocal fatigue
• Difficulty with certain sounds or words

The severity of symptoms can vary, and they may worsen with stress or fatigue.

Diagnosis

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

• A detailed medical history
• Laryngeal examination using laryngoscopy
• Voice assessment

Differential diagnosis is important to distinguish ADSD from other voice disorders such as muscle tension dysphonia or vocal cord paralysis.

Treatment

There is no cure for ADSD, but several treatment options can help manage symptoms:

Botulinum Toxin Injections

Botulinum toxin (Botox) injections into the affected muscles are the most common treatment for ADSD. The toxin temporarily weakens the muscles, reducing spasms and improving voice quality. Injections typically need to be repeated every 3-6 months.

Voice Therapy

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

Surgical Options

In some cases, surgical interventions such as selective laryngeal adductor denervation-reinnervation (SLAD-R) may be considered.

Prognosis

While ADSD is a chronic condition, many patients achieve significant improvement in voice quality with treatment. Ongoing management is often necessary to maintain voice function.

Also see

• Spasmodic Dysphonia
• Laryngeal Dystonia
• Voice Disorders
• Botulinum Toxin Therapy