Essential tremor (ET) is the most common movement disorder. It typically presents with bilaterally symmetric hand tremor of 4–8 Hz which is present during postural changes. The tremor is also present during action and absent at rest. A family history is positive in one-half of patients. It is felt to have an autosomal dominant inheritance. The tremor of ET is more symmetric than the tremor of Parkinson’s disease (PD). Rigidity and bradykinesia are not seen. ET often involves the upper extremities, head, and voice. It can interfere with fine motor movements such as the use of eating utensils and handwriting. There is no significant response to dopaminergic medications. The tremor tends to worsen with time. It is worsened by emotional factors and, in some patients, temporarily improved by consumption of alcohol.
References and Readings
- Cersosimo, M. C., & Koller, W. C. (2004). Essential tremor. In R. L. Watts & W. C. Koller (Eds.), Movement disorders (2nd ed., pp. 431–458). New York: McGraw-Hill.Google Scholar