What is Laryngeal Dystonia

TL;DR: Laryngeal dystonia, often referred to as spasmodic dysphonia, is a rare neurological disorder characterized by involuntary muscle spasms in the larynx (voice box) that interrupt normal speech. It is a focal dystonia that specifically affects the coordination of vocal cord muscles, leading to a strained, shaky, or breathy voice quality.

What is laryngeal dystonia and how does it affect the body?

Laryngeal dystonia is a task-specific movement disorder where the brain sends abnormal signals to the muscles of the vocal cords. While the vocal cords themselves are anatomically healthy, the spasms prevent them from vibrating normally during speech. Because this condition is specific to the act of speaking, individuals often find that their voice sounds perfectly normal during non-speech activities like laughing, crying, or singing.

What are the primary types of laryngeal dystonia?

Clinicians generally categorize laryngeal dystonia into three distinct subtypes based on how the vocal cords react during spasms:

• Adductor laryngeal dystonia: The most common form, where the vocal cords slam shut involuntarily, causing a strained, strangled, or "choked" voice quality.


• Abductor laryngeal dystonia: A rarer form where the vocal cords pull apart, resulting in a breathy, whispered, or weak-sounding voice.


• Mixed laryngeal dystonia: A combination of both adductor and abductor symptoms, leading to an unpredictable voice quality.

How common is laryngeal dystonia and who does it affect?

Laryngeal dystonia is considered a rare condition, with estimated prevalence rates ranging from 1 to 5 per 100,000 individuals worldwide. Onset typically occurs in adulthood, most commonly between the ages of 30 and 50. While both men and women are affected, clinical data suggests a slightly higher prevalence in women. There is no specific geographic predisposition, and it is observed globally across all ethnic populations.

What causes laryngeal dystonia and how is it different?

The exact cause of laryngeal dystonia remains unknown, though it is understood to be a form of basal ganglia dysfunction within the central nervous system. Unlike common voice disorders caused by vocal nodules, polyps, or muscle tension dysphonia, laryngeal dystonia is a neurological movement disorder. Differentiation is key; a specialist, typically a laryngologist or neurologist, must rule out structural damage to the vocal cords to confirm a diagnosis of laryngeal dystonia.

Next steps

• Consult a movement disorder specialist or a fellowship-trained laryngologist for a formal evaluation.


• Connect with the 4 community members on DiseaseMaps.org who are currently managing laryngeal dystonia.


• Consider speech-language pathology focused on voice rehabilitation to develop compensatory strategies.


• Inquire about botulinum toxin (Botox) injections, which are the gold-standard treatment for managing laryngeal dystonia symptoms.

Medical disclaimer: This content is for informational purposes only and does not constitute professional medical advice, diagnosis, or treatment. Always seek the advice of your physician with any questions regarding a medical condition.

References

• NIH Genetic and Rare Diseases Information Center (GARD): Spasmodic Dysphonia


• Orphanet: Focal Dystonia (including Laryngeal Dystonia)


• National Spasmodic Dysphonia Association (NSDA)


• PubMed: Clinical Overview of Laryngeal Dystonia and Treatment Modalities