Examination of a Patient with Essential Tremor
Essential tremor (ET) is the most common cause of postural and kinetic tremor arising from a primary neurologic disorder with an estimated worldwide prevalence of 5%. The incidence of ET increases with age but often affects young individuals. ET is also referred to as familial tremor when there is a family history which is present in about 50% of cases. ET appears to be genetically heterogeneous. Although genetic linkage studies have discovered a genetic basis for ET in several affected families, the genetic basis for ET has not been identified in the vast majority of cases. The pathological basis for ET remains uncertain, although postmortem cerebellar Purkinje cell abnormalities have been found in some patients.
KeywordsDeep Brain Stimulation Essential Tremor Affected Family Worldwide Prevalence Pathological Basis
Exam of patients w. essential tremor.mp4 (MP4 63,703KB)
Clip 1: the patient is examined using the essential tremor rating assessment scale (TETRAS). He displays mild postural tremor of his extended hands, delayed appearance of large amplitude tremor of right hand in the “wing-beating” posture, a tremor drawing spirals with his left hand more affected than the right hand, tremor positioning a pen point above a target, and writing tremor. Clip 2: another patient with ET is examined using TETRAS. He exhibits voice tremor, head tremor, and tremor of his hands while extended and in the wing-beating position. Drawing of a spiral, positioning a pen point above a target, and writing are all tremulous.
- 4.Elble R, Comella C, Fahn S, the Tremor Research Group. The essential tremor rating assessment scale (TETRAS). Mov Disord. 2008;23 Suppl 1:S357.Google Scholar