Torsion dystonia

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Torsion dystonia
Other namesDystonia musculorum deformans
Specialty Neurology   OOjs UI icon edit-ltr-progressive.svg

Torsion dystonia, also known as dystonia musculorum deformans, is a disease characterized by painful muscle contractions resulting in uncontrollable distortions. This specific type of dystonia is frequently found in children, with symptoms starting around the ages of 11 or 12. It commonly begins with contractions in one general area such as an arm or a leg that continue to progress throughout the rest of the body. It takes roughly 5 years for the symptoms to completely progress to a debilitating state.

Contents

Causes

The disease is caused by a genetic disorder which results in a defect in a protein called Torsin A. [1] A mutation in the DYT1 gene causes the loss of an amino acid, glutamic acid, in the Torsin A protein. Torsin A is an evolutionarily conserved AAA+ ATPase. The defective protein disrupts communication in neurons that control muscle movement and muscle control. This mutation is most usually inherited from a parent but can occur spontaneously. [2] The disease is caused by a dominant allele, meaning that the person affected needs only one copy of the mutated DYT1 gene to have symptoms. [3] However, only 30 to 40 percent of those that do have the gene actually have symptoms, leading researchers to believe that there are other factors involved. [4]

Diagnosis

Classification

Several types of torsion dystonia affect different areas of the body. However, it is unknown if the gene that causes Early-onset torsion dystonia is responsible for the other dystonias as well.

Treatment

There is no cure for torsion dystonia. However, there are several medical approaches that can lessen the symptoms of the disease. The treatment must be patient-specific, taking into consideration all of the previous and current health complications. The doctor who creates the treatment must have intimate knowledge of the patient's health and create a treatment plan that covers all of the symptoms, focusing on the most chronic areas.

The first step for most with the disorder is some form of physical therapy in order for the patient to gain more control over the affected areas. The therapy can help patients with their posture and gain control over the areas of their body that they have the most problems with.

The second step in the treatment process is medication. The medications focus on neurotransmitters that control muscle movement. The medications on the market today are anticholinergics, benzodiazepines, baclofen, dopaminergic agents/dopamine-depleting agents, and tetrabenazine. [5] Each medication is started on a low dosage and gradually increased to higher doses as the disease progresses and the side effects are known for the individual.

A more site-specific treatment is the injection of botulinum toxin. It is injected directly into the muscle and works by preventing the release of acetylcholine, resulting in flaccid paralysis of the muscle. The injections are not a treatment for the disease but are a means to control its symptoms. [6]

Surgery may be considered for patients who do not respond to oral medications or injections. The type of surgery performed is specific to the type of dystonia that the patient has[ citation needed ]. A systematic review found that some patients benefit from deep brain stimulation (DBS) surgery, but the studies may have been subject to financial bias. [7]

Prevalence

The disease is more commonly found amongst Ashkenazi Jews. The occurrence of torsion dystonia in the Ashkenazi Jewish population as stated by the Department of Epidemiology and Public Health of Yale University School of Medicine in New Haven, Connecticut; "Reports dating to the beginning of this century describe Ashkenazi Jewish (AJ) families with multiple cases of ITD either in siblings (Schwalbe 1908; Bernstein 1912; Abrahamson 1920) or in parents and offspring (Wechsler and Brock 1922; Mankowsky and Czerny 1929; Regensberg 1930). The first comprehensive evaluation of the mode of inheritance of ITD in Jewish and non-Jewish families was described by Zeman and Dyken (1967), who concluded that the disorder was inherited as an autosomal dominant with incomplete penetrance in both populations. Although they concluded that the gene frequency was higher in the AJ population than in non-Jews, no difference in the mode of inheritance or disease mechanism was construed."[ citation needed ]

Research

A 1969 study of torsion dystonia patients found an average IQ 10 points higher than controls matched for age, sex, and ethnic background. [8]

References

  1. Ozelius, L. J.; Hewett, J. W.; Page, C. E.; Bressman, S. B.; Kramer, P. L.; Shalish, C; De Leon, D; Brin, M. F.; Raymond, D; Corey, D. P.; Fahn, S; Risch, N. J.; Buckler, A. J.; Gusella, J. F.; Breakefield, X. O. (1997). "The early-onset torsion dystonia gene (DYT1) encodes an ATP-binding protein". Nature Genetics. 17 (1): 40–8. doi:10.1038/ng0997-40. PMID   9288096. S2CID   29095964.
  2. Hjermind, L. E.; Werdelin, L. M.; Sørensen, S. A. (2002). "Inherited and de novo mutations in sporadic cases of DYT1-dystonia". European Journal of Human Genetics. 10 (3): 213–6. doi: 10.1038/sj.ejhg.5200782 . PMID   11973627.
  3. Risch, N. J.; Bressman, S. B.; Deleon, D; Brin, M. F.; Burke, R. E.; Greene, P. E.; Shale, H; Claus, E. B.; Cupples, L. A.; Fahn, S (1990). "Segregation analysis of idiopathic torsion dystonia in Ashkenazi Jews suggests autosomal dominant inheritance". American Journal of Human Genetics. 46 (3): 533–8. PMC   1683634 . PMID   2309703.
  4. NIH GHR
  5. Cloud, L. J.; Jinnah, H. A. (2010). "Treatment strategies for dystonia". Expert Opinion on Pharmacotherapy. 11 (1): 5–15. doi:10.1517/14656560903426171. PMC   3495548 . PMID   20001425.
  6. Delnooz, C. C.; Van De Warrenburg, B. P. (2012). "Current and future medical treatment in primary dystonia". Therapeutic Advances in Neurological Disorders. 5 (4): 221–40. doi:10.1177/1756285612447261. PMC   3388529 . PMID   22783371.
  7. Rodrigues, Filipe B; Duarte, Gonçalo S; Prescott, David; Ferreira, Joaquim; Costa, João (2019). "Deep brain stimulation for dystonia". Cochrane Database of Systematic Reviews. 2019 (1) CD012405. doi:10.1002/14651858.CD012405.pub2. ISSN   1465-1858. PMC   6353249 . PMID   30629283.
  8. Eldridge, R.; Harlan, A.; Cooper, I.; Riklan, M. (1970). "Superior Intelligence in Recessively Inherited Torsion Dystonia". The Lancet. 295 (7637): 65–67. doi:10.1016/S0140-6736(70)91848-9. PMID   4188627.

Further reading