May 4, 2015: Rapid-Onset Dystonia Parkinsonism
May 4, 2015
Rapid-Onset Dystonia Parkinsonism
Rapid-Onset Dystonia Parkinsonism, DYT12, is a rare movement disorder characterized by the acute onset of both dystonia and parkinsonian features. Mutations to the Na+/K+- ATPase alpha three subunit have been associated with DYT12, located within the ATP1A3 gene on chromosome 19. The disorder is inherited in an autosomal dominant fashion, affecting a small population of families. Typical onset is in the second to third decades and is often the result of a significant physiological stressor, whether physical or psychological. Dystonia typically affects bulbar musculature resulting in speech and swallowing difficulties, as well as focal limb muscles. Bradykinesia and postural instability are the most frequent parkinsonian manifestations observed. Although tremor is less common, it can be seen mutation negative cases with a higher prevalence. A rostrocaudal gradient of symptoms, affecting the face more than arm more than leg, is commonly seen in mutation positive cases of DYT12. Typical dopaminergic therapy is usually not successful in DY12 in comparison to the dopa-responsive dystonias. Genetic testing remains the gold standard for diagnosis.
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Submitted by James Addington, M.D. Resident Physician, Department of Neurology, University of Virginia
Disclosures: Dr. Addington is a member of the Residents & Fellows Section of Neurology.