Primary Orthostatic Tremor

Timothy C. Hain, MD

Last updated 9/2008

Primary orthostatic tremor (OT) consists of rhythmical muscle contractions in the legs causing discomfort or unsteadiness while standing. It was first described by Heilman in 1984. The tremor is typically 12 to 18 Hz, with partial or complete cessation while walking or sitting.

It is presently controversial whether OT is a variant of essential tremor or
a diagnostic entity in its own right.

Diagnosis is usually obtained based on clinical evaluation combined with surface electromyogram (EMG). Posturography may also be used to screen for orthostatic tremor (Karlberg, 2005). Misdiagnosis is common and many patients are initially thought to have a non-organic (psychogenic) balance disorder. Frequency domain analysis of surface EMG or sway traces can diagnose this condition (Yarrow et al, 2001).

According to Pradalier and associates(2002), clonzepam is the preferred treatment for orthostatic tremor. Other drugs that may be effective include primidone and gabapentin (Neurontin). A recent small trial confirmed the effectiveness of gabapentin in tremor amplitude and improving quality of life (Rodrigues, 2005, 2006).

References

  • Karlberg M, Fransson PA et al. Posturography can be used to screen for primary orthostatic tremor, a rare cause of dizziness. Otol Neurotol. 26(6):1200-3, 2005.
  • Pradalier A, Apartis E, Vincent D, Campinos C.Rev Med Interne 2002 Feb;23(2):193-7 Related Articles, Links [Primary orthostatic tremor] [Article in French]
  • Rodrigues JP, Edwards DJ et al. Gabapentin can improve postural stability and quality of life in primary orthostatic tremor. Movement Disorders. 20(7):865-70, 2005.
  • Rodriques JP, Edwards DJ et al. Blinded placebo crossover study of gabapentin in primary orthostatic tremor. Movement Disorders. 20(7):900-5, 2006.
  • Yarrow et al. Force platform recordings in the diagnosis of primary orthostatic tremor. Gait and Posture 13(2001), 27-34