Orthostatic Tremor: An Update on a Rare Entity.

Area of Science:

• Neurology
• Movement Disorders

Background:

• Orthostatic tremor (OT) is an understudied movement disorder.
• Limited research exists compared to Parkinson's disease or essential tremor.

Approach:

• Systematic literature review of "orthostatic tremor" and "shaky leg syndrome" in PubMed (1966-2016).
• Included 219 entries, supplemented by author files.

Key Points:

• OT is rare, with understanding based on small case series.
• Evidence suggests OT is progressive and clinically heterogeneous (primary/secondary).
• Broader features include cerebellar signs, cognitive impairment, and personality changes.
• Neuroimaging reveals anatomical/functional changes, potentially indicating neuronal loss.

Conclusions:

• OT may represent a disease family unified by leg tremor but with diverse causes and clinical presentations.
• Further research is crucial to elucidate the pathogenesis of orthostatic tremor.