Orthostatic tremor.

Orthostatic tremor is characterised by a feeling of unsteadiness that is accompanied by a high frequency (13-18 Hz) tremor of the legs when standing, and which is relieved by sitting or walking. We describe a typical patient whose condition gradually progressed so that eventually he could no longer stand still. We discuss the clinical features, management and pathogenesis, and highlight the need for awareness of this condition because the diagnosis is often missed or delayed.