Rare Nephrology News

Disease Profile

Spasmodic dysphonia

Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.


US Estimated

Europe Estimated

Age of onset





Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.


Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.


dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.


recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.


Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.


Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.


Not applicable


Other names (AKA)

Abductor spasmodic dysphonia (type); Mixed spasmodic dysphonia (type); Adductor spasmodic dysphonia (type);


Congenital and Genetic Diseases; Nervous System Diseases; RDCRN


Spasmodic dysphonia is a disease caused by involuntary movements of one or more muscles of the voice box (larynx). Signs and symptoms may range from occasional difficulty saying a word or two to substantial difficulty speaking that interferes with communication. Spasmodic dysphonia causes the voice to have a tight, strained, or strangled quality. While the cause of spasmodic dysphonia is unknown, some researchers think it might be caused by problems with the basal ganglia in the brain.[1]

Some cases of spasmodic dysphonia occur along with other diseases that affect the nervous system such as movement disorders. Spasmodic dysphonia may be inherited, or it may occur after a trauma to the voice box such as an injury or a severe cold. Diagnosis of spasmodic dysphonia is based on an exam by a multidisciplinary team, including an otolaryngologist. This exam may include a videolaryngostroboscopy. Treatment may include surgery, Botox injections, and speech therapy.[1]


There is a wide range of speaking difficulty that may be associated with spasmodic dysphonia. Some affected individuals may occasionally struggle to say a word or two, while others may have substantial difficulty speaking that interferes with communication. Some types of speech, such as singing, laughing, or yelling, may be unaffected.[2] There are three different types of spasmodic dysphonia:[1]

  • Adductor spasmodic dysphonia: causes the vocal cords to close and stiffen, resulting in a strained voice
  • Abductor spasmodic dysphonia: causes the vocal cords to stay open, resulting in a weak and quiet voice
  • Mixed spasmodic dysphonia: causes the vocal cords to both open and close inappropriately, resulting in a mix of symptoms

While anyone can be affected, spasmodic dysphonia more often affects women and is more likely to begin between the ages of 30 and 50 years.[1] The onset of symptoms may be sudden or may be relatively mild and progress over a period of time.[2] Some individuals with the disease may have a tremor (shaking) in other body parts, such as the hands, or symptoms of another neurological disease.[3]


The cause of spasmodic dysphonia is unknown.[1][3][4] Some researchers think that spasmodic dysphonia is caused by problems with a structure in the brain called the basal ganglia. The basal ganglia control involuntary movements in the body, including the involuntary movements of the vocal cords. Specifically, it is thought that the chemical signals (neurotransmitters) in the basal ganglia do not work correctly in people who have spasmodic dysphonia. When the neurotransmitters do not work correctly, the basal ganglia cannot communicate with the voice box to tell the vocal cords when to move.[3][4]

For some people, the onset of symptoms may occur after an illness, after an injury affecting the voice box, or after a time of emotional stress. Other individuals with spasmodic dysphonia cannot identify a reason that they developed symptoms of the disease.[1][3]


Diagnosis of spasmodic dysphonia is based on clinical evaluation by a multidisciplinary team of healthcare providers. This team may include a speech-language pathologist who evaluates voice production and voice quality, a neurologist who rules out other neurological diseases that may cause spasmodic dysphonia, and an otolaryngologist who examines the vocal cords and their movements. A procedure called videolaryngostroboscopy is often performed to assess the vibration of the vocal cords. This procedure uses a very small camera to record if the vocal cords are vibrating correctly during speech.[3] Other procedures may include imaging of the brain using a CT scan or MRI to rule out other neurological disorders.[3]


The treatment for spasmodic dysphonia focuses on improving symptoms of the disease. Treatment options include speech therapy, Botox injections into the vocal cords, and surgery to try to fix the opening or closing of the vocal cords.[1][3] The exact treatment that will be available depends on the type of spasmodic dysphonia each affected individual has.[3]


Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

    Learn more

    These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

    Where to Start

    • The National Institute on Deafness and Other Communication Disorders (NIDCD) conducts and supports biomedical and behavioral research and research training in the normal and disordered processes of hearing, balance, smell, taste, voice, speech, and language. Click on the link to view information on this topic.
    • The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.

      In-Depth Information

      • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
      • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
      • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.


        1. Spasmodic Dysphonia. National Institute on Deafness and Other Communication Disorders (NIDCD). March 6, 2017; https://www.nidcd.nih.gov/health/spasmodic-dysphonia.
        2. Jinnah HA. Laryngeal Dystonia. National Organization for Rare Disorders. 2017; https://rarediseases.org/rare-diseases/laryngeal-dystonia/.
        3. Pitman MJ, Kamat AR, and Baredes S. Spasmodic Dysphonia. Medscape Reference. June 15, 2017; https://emedicine.medscape.com/article/864079-overview.
        4. Spasmodic Dysphonia: Causes. National Spasmodic Dysphonia Association. https://www.dysphonia.org/causes.php. Accessed 9/20/2017.
        5. Hintze JM, Ludlow CL, Bansberg SF, Adler CH, and Lott DG. Spasmodic Dysphonia: A Review. Part 1: Pathogenic Factors. Otolaryngology Head and Neck Surgery. August 1, 2017; https://www.ncbi.nlm.nih.gov/pubmed/28850801.

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