The exact prevalence of POT is unknown, although it is estimated to affect < 1 per million individuals. It predominantly affects older adults > 50 years old, with women representing about 64% of cases.

The cause of primary orthostatic tremor is idiopathic (unknown). It is considered a neurologic disorder rather than a muscle disease, involving abnormal oscillator activity in the cerebellum or brainstem. POT may be a variation of another movement disorder called essential tremor, which is inherited in an autosomal dominant pattern, but research is still ongoing. Most cases are sporadic, occurring in people with no family history of the disorder.

POT appears as shaking and lack of balance when standing up, and is associated with an intense and disabling sense of unsteadiness, fear of falling, discomfort, dizziness, shaking, trembling sensations, and/or trembling of limbs and trunk. Symptoms while standing are reduced or abolished by walking, leaning on support, sitting, and lying down. Patients often shuffle, wobble, or seek support when standing. Despite feelings of imbalance, actual falls are relatively rare. Many patients develop anticipatory anxiety in situations requiring prolonged standing, such as waiting in line or social gatherings.

POT diagnosis is based on clinical examination and surface electromyography (EMG). A history of an inability to stand still, relieved by walking is the strongest initial indicator. EMG electrical activity measurements in weight-bearing muscles showing a tremor frequency > 12 Hertz are considered to be the “gold standard” criteria for establishing a diagnosis. Because the tremor is fast and difficult to see, POT is frequently misdiagnosed. Additional testing such as brain MRI or laboratory tests are often performed to rule out other conditions.

There is no cure for POT, and treatment focuses on symptom management. Responses to treatment vary greatly among patients.

• Medications: Clonazepam is considered a first-line treatment in reducing the amplitude of tremors;  anticonvulsant seizure medications like Gabapentin or Primidone are also commonly prescribed.

• Lifestyle and assistive devices such as use of a cane, walker, or carrying a portable folding stool can dramatically improve quality of life and provide immediate relief when out in public.

• Avoidance of prolonged standing.

• Physical therapy to improve balance.

• For severe, refractory cases where medications fail, surgical options such as deep brain stimulation (DBS) targeting the thalamus have been used.

POT is generally a slowly progressive disorder. Over time, the duration a person can stand still may decrease and the tremor may spread. Many patients achieve partial symptom control with medication. The inability to stand can make everyday tasks and social engagements highly challenging. The condition is not fatal and does not alter life expectancy.

1. Benito-León, J., & Domingo-Santos, Á. 2016. “Orthostatic Tremor: An Update on a Rare Entity.“ Tremor and other hyperkinetic movements (New York, N.Y.), 6, 411. https://doi.org/10.7916/D81N81BT.

2. National Organization for Rare Disorders (NORD):  Primary orthostatic tremor.

3. Orphanet:  Primary orthostatic tremor.

4. Cleveland Clinic: Essential tremor