Essential Tremor Syndrome
- A postural (occurring with voluntary maintenance of a position against gravity) or kinetic (occurring during voluntary movement) flexion–extension tremor that is slow and rhythmic and primarily affects the hands, forearms, head, or voice with a frequency of 4 to 12 Hz
- Older patients tend to have lower frequency tremors, whereas younger patients exhibit frequencies in the higher range.
- May be familial, sporadic, or associated with other movement disorders
- Incidence and prevalence increase with age, but symptom onset can occur at any age.
- The tremor can be intermittent and exacerbated by emotional or physical stressors, fatigue, and caffeine.
- System(s) affected include neurologic, musculoskeletal, ear/nose/throat (ENT) (voice).
Essential tremor is the most common pathologic tremor in humans.
- Can occur at any age but bimodal peaks exist in the 2nd and 6th decades
- Incidence rises significantly after age 49 years.
The overall prevalence for essential tremor has been estimated between 0.4% and 0.9% but is increased in older patients with an estimated prevalence of 4.6% at age 65 years and up to 22% at age 95 years.
Etiology and Pathophysiology
- Suspected to originate from an abnormal oscillation within thalamocortical and cerebello-olivary loops, as lesions in these areas tend to reduce essential tremor
- Essential tremor is not a homogenous disorder; many patients have other motor manifestations and nonmotor features, including cognitive and psychiatric symptoms.
- Positive family history in 50–70% of patients; autosomal dominant inheritance is demonstrated in many families with poor penetrance. Twin studies suggest that environmental factors are also involved.
- A link to genetic loci exists on chromosomes 2p22–2p25, 3q13, and 6p23. In addition, a Ser9Gly variant in the dopamine D3 receptor gene on 3q13 has been suggested as a risk factor.
Commonly Associated Conditions
- Can be present in 10% of patients with Parkinson disease (PD); characteristics of PD that distinguish it from essential tremor include 3- to 5-Hz resting tremor; accompanying rigidity, bradykinesia, or postural instability; and no change with alcohol consumption
- Patients with essential tremor have a 4% risk of developing PD.
- Resting tremor, typically of the arm, may be seen in up to 20–30% of patients with essential tremor. Although action tremor is the hallmark feature of essential tremor, it is commonly found in patients with PD as well.
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Domino, Frank J., et al., editors. "Essential Tremor Syndrome." 5-Minute Clinical Consult, 27th ed., Wolters Kluwer, 2020. www.unboundmedicine.com/5minute/view/5-Minute-Clinical-Consult/116221/all/Essential_Tremor_Syndrome.
Essential Tremor Syndrome. In: Domino FJF, Baldor RAR, Golding JJ, et al, eds. 5-Minute Clinical Consult. Wolters Kluwer; 2020. https://www.unboundmedicine.com/5minute/view/5-Minute-Clinical-Consult/116221/all/Essential_Tremor_Syndrome. Accessed May 28, 2023.
Essential Tremor Syndrome. (2020). In Domino, F. J., Baldor, R. A., Golding, J., & Stephens, M. B. (Eds.), 5-Minute Clinical Consult (27th ed.). Wolters Kluwer. https://www.unboundmedicine.com/5minute/view/5-Minute-Clinical-Consult/116221/all/Essential_Tremor_Syndrome
Essential Tremor Syndrome [Internet]. In: Domino FJF, Baldor RAR, Golding JJ, Stephens MBM, editors. 5-Minute Clinical Consult. Wolters Kluwer; 2020. [cited 2023 May 28]. Available from: https://www.unboundmedicine.com/5minute/view/5-Minute-Clinical-Consult/116221/all/Essential_Tremor_Syndrome.
* Article titles in AMA citation format should be in sentence-case
TY - ELEC T1 - Essential Tremor Syndrome ID - 116221 ED - Domino,Frank J, ED - Baldor,Robert A, ED - Golding,Jeremy, ED - Stephens,Mark B, BT - 5-Minute Clinical Consult, Updating UR - https://www.unboundmedicine.com/5minute/view/5-Minute-Clinical-Consult/116221/all/Essential_Tremor_Syndrome PB - Wolters Kluwer ET - 27 DB - 5-Minute Clinical Consult DP - Unbound Medicine ER -