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Disease Profile

Primary orthostatic tremor

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)

OT; Shaky leg syndrome; Orthostatic tremor, primary;


Nervous System Diseases


Primary orthostatic tremor (POT) is a rare, progressive movement disorder that causes unsteadiness when standing still, due to a rapid tremor affecting the legs and trunk.[1][2] The tremor is sometimes described as having “shaky legs,” and it improves or disappears when walking, sitting, or lying down.[1][2][3] This may cause people with POT to attempt to sit again or walk immediately after standing, for fear of falling.[2][3] People with POT may also experience tiredness, physical exhaustion, muscle stiffness or weakness, and/or pain.[3][4] Symptoms tend to gradually worsen over time and may lead to the need for a mobility aid such as a cane, scooter, or wheelchair.[1][3][4]

The diagnosis of POT relies on a clinical exam as well as a specialized test called a surface electromyogram (EMG), which measures electrical activity in the muscles.[3] The cause of POT is not completely understood, but the disorder is thought to involve dysfunction of the brain’s ability to regulate nerve signals that control muscle activity.[1][3] Some researchers believe that POT is a type of essential tremor.[3]

Treatment usually involves medications used to control seizures (anticonvulsants) such as clonazepam or gabapentin. In some cases, treatment may include medications used for Parkinson’s disease (levodopa or pramipexole), and/or botulinum toxin (Botox) injections in the leg muscles. More than one therapy may be tried before finding one that helps.[3] POT does not appear to alter life expectancy. However, quality of life for people with POT may be severely impaired due to physical symptoms, fear of falling, and uncertainty about the course of the disorder.[1]


This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Medical Terms Other Names
Learn More:
80%-99% of people have these symptoms
EMG abnormality
Muscle spasm
30%-79% of people have these symptoms
Muscle ache
Muscle pain

[ more ]

5%-29% of people have these symptoms
Abnormality of extrapyramidal motor function


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

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    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

      In-Depth Information

      • 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.
      • PubMed is a searchable database of medical literature and lists journal articles that discuss Primary orthostatic tremor. Click on the link to view a sample search on this topic.


        1. Czernecki V, Broussolle E, Bonnet C, Falissard B, Jahanshahi M, Vidailhet M, Roze E. Health-Related Quality of Life Is Severely Affected in Primary Orthostatic Tremor. Front Neurol. January 15, 2018; 8:747. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5775514/.
        2. Lenka A, Pal PK, Bhatti DE, Louis ED. Pathogenesis of Primary Orthostatic Tremor: Current Concepts and Controversies. Tremor Other Hyperkinet Mov (N Y). November 17, 2017; 7:513. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5712672/.
        3. Jankovic J. Primary Orthostatic Tremor. National Organization for Rare Disorders (NORD). 2017; https://www.rarediseases.org/rare-disease-information/rare-diseases/byID/1133/viewAbstract.
        4. Living with orthostatic tremor. National Tremor Foundation. https://tremor.org.uk/orthostatic-tremor.html. Accessed 1/17/2019.