3. Introduction
◦ Shaky legs syndrome
◦ First coined in 1984 by Heilman
◦ Earlier descriptions of this entity date back to 1970 when Pazzaglia et al. reported on three
patients with a peculiar disorder only occurring on standing.
◦ Rare and intriguing
◦ Unsteadiness when standing that is relieved when sitting or walking
◦ Fast tremor of 13–18 Hz in the legs, trunk, and, sometimes, the arms
◦ Primary (idiopathic) OT with or without postural arm tremor, and those with “OT plus,” in whom
there are additional associated movement disorders, mainly parkinsonism.
Adebayo, P. B. (2016). Orthostatic tremor: current challenges and future prospects. DEGENERATIVE NEUROLOGICAL AND NEUROMUSCULAR DISEASE, 6, 17-24.
Benito-León, J., & Domingo-Santos, Á. (2016). Orthostatic Tremor: An Update on a Rare Entity. Tremor and Other Hyperkinetic Movements, 6, 411. http://doi.org/10.7916/D81N81BT
4. Epidemiology
◦ Onset: 6th decade of life
◦ Female: male 4:1
◦ Mostly sporadic
◦ Early onset OT
Piboolnurak P, Yu QP, Pullman SL. Clinical and neurophysiologic spectrum of orthostatic tremor: case series of 26 subjects. Mov Disord. 2005;20(11):1455–1461.
Yaltho TC, Ondo WG. Orthostatic tremor: a review of 45 cases. Parkinsonism Relat Disord. 2014;20(7):723–725.
Benito-León, J., & Domingo-Santos, Á. (2016). Orthostatic Tremor: An Update on a Rare Entity. Tremor and Other Hyperkinetic Movements, 6, 411. http://doi.org/10.7916/D81N81BT
5. Risk Factors / Etiology
Benito-León, J., & Domingo-Santos, Á. (2016). Orthostatic Tremor: An Update on a Rare Entity. Tremor and Other Hyperkinetic Movements, 6, 411. http://doi.org/10.7916/D81N81BT
6. Pathophysiology
◦ Cerebello-thalamocorticospinal loop
◦ Central oscillator at posterior fossae
◦ Spinal cord may generate 16 Hz tremor
◦ Tremulous disruption of proprioceptive afferent activity from the legs causing a cocontraction of
the leg muscles to increase stability
◦ Dopaminergic system
◦ Neurodegenerative process
Adebayo, P. B. (2016). Orthostatic tremor: current challenges and future prospects. DEGENERATIVE NEUROLOGICAL AND NEUROMUSCULAR DISEASE, 6, 17-24.
Benito-León, J., & Domingo-Santos, Á. (2016). Orthostatic Tremor: An Update on a Rare Entity. Tremor and Other Hyperkinetic Movements, 6, 411. http://doi.org/10.7916/D81N81BT
7. Clinical Manifestation
◦ Unsteadiness during stance
◦ Tremor
◦ Leg pain
◦ Mostly also affecting other body parts
◦ Symptoms decrease by sitting, walking, or leaning against the wall
Benito-León, J., & Domingo-Santos, Á. (2016). Orthostatic Tremor: An Update on a Rare Entity. Tremor and Other Hyperkinetic Movements, 6, 411. http://doi.org/10.7916/D81N81BT
8. Clinical Examination
◦ High frequency tremor (13-18 Hz)
◦ Palpate gastrocnemius or quadriceps muscles (fine amplitude rippling)
◦ Easily felt than seen due to the high frequency
◦ Knee tremor
◦ Auscultation using a stethoscope of the gastrocnemius muscles can sometimes reveal a
characteristic of barely audible noise akin to the sound of distant rotor blades of a helicopter.
Benito-León, J., & Domingo-Santos, Á. (2016). Orthostatic Tremor: An Update on a Rare Entity. Tremor and Other Hyperkinetic Movements, 6, 411. http://doi.org/10.7916/D81N81BT
9. Electromyography
Benito-León, J., & Domingo-Santos, Á. (2016). Orthostatic Tremor: An Update on a Rare Entity. Tremor and Other Hyperkinetic Movements, 6, 411. http://doi.org/10.7916/D81N81BT
11. Laboratory and Imaging
◦ Thyroid function tests,
◦ Serum protein electrophoresis to rule out gammopathies,
◦ Vitamin B12 levels,
◦ Diagnostic studies to exclude Wilson’s disease (e.g. serum ceruloplasmin),
◦ Brain MRI
Lee HM, Kwon DY, Park MH, Koh SB, Kim SH. Symptomatic orthostatic tremor with progressive cognitive impairment in spinal cord lesions. Clin neurol Neurosurg. 2012;114:1329–1331. doi:10.1016/j.clineuro.2012.03.021.
12. Time Course and Progression
◦ Slowly progressive
◦ Spatial spread
◦ May proceed to develop other neurological conditions, especially PD and essential tremor.
◦ Other neurological disorders that have been documented in patients with OT include dementia with
Lewy bodies, ataxic disorders, restless leg syndrome, orofacial dyskinesia, and periodic limb
movement in sleep.
◦ QOL:Physical functioning, physical role limitations, social functioning, and emotional role limitations
were the predominantly impaired domains of quality of life depression
Adebayo, P. B. (2016). Orthostatic tremor: current challenges and future prospects. DEGENERATIVE NEUROLOGICAL AND NEUROMUSCULAR DISEASE, 6, 17-24.
13. Differential Diagnosis
◦ Essential tremor,
◦ Parkinson’s disease,
◦ Restless leg syndrome,
◦ Lumbar stenosis,
◦ Psychogenic balance disorders.
Gerschlager W, Munchau A, Katzenschlager R, et al. Natural history and syndromic associations of orthostatic tremor: a review of 41 patients. Mov Disord. 2004;19:788–795. doi: 10.1002/mds.20132.
Piboolnurak P, Yu QP, Pullman SL. Clinical and neurophysiologic spectrum of orthostatic tremor: case series of 26 subjects. Mov Disord. 2005;20:1455–1461.
Pfeiffer G, Hinse P, Humbert T, Riemer G. Neurophysiology of orthostatic tremor. Influence of transcranial magnetic stimulation. Electromyogr Clin Neurophysiol. 1999;39:49–53
14. Treatment
◦ Non-pharmacological:
◦ Portable stools
◦ A tripod walking stick
◦ Weight reduction
◦ Patient and family education
◦ Deep brain & spinal stimulation
Benito-León, J., & Domingo-Santos, Á. (2016). Orthostatic Tremor: An Update on a Rare Entity. Tremor and Other Hyperkinetic Movements, 6, 411. http://doi.org/10.7916/D81N81BT
15. Treatment
Benito-León, J., & Domingo-Santos, Á. (2016). Orthostatic Tremor: An Update on a Rare Entity. Tremor and Other Hyperkinetic Movements, 6, 411. http://doi.org/10.7916/D81N81BT
16. Summary
◦ Rare movement disorder
◦ Neurological vs non-motor features
◦ Treatment including non-pharmacological, pharmacological, and deep brain/spinal stimulation.
