Essential Tremor
Essential tremor is the most common movement disorder, characterized by a bilateral tremor that mainly affects the hands and arms and appears with posture (postural) and movement (kinetic). It often runs in families. Mild cases may not require treatment; medication is used when there is functional impairment, and surgical options such as deep brain stimulation (DBS) are used in resistant cases.
Last updated: 2026-06-07
Definition
Essential tremor is the most common movement disorder and is characterized by a bilateral tremor that becomes evident with posture (when the arms are held out) and with movement (when performing a task). The hands are most often affected, followed by the head, voice, jaw and, less commonly, the legs. There is usually no tremor at rest, or only minimal tremor; this feature is important in distinguishing it from Parkinson's disease. The frequency of the tremor increases with age.
Causes and Risk Factors
The exact mechanism of essential tremor is not fully understood, but abnormal oscillations in the cerebellum-thalamus-cortex motor networks of the brain are thought to play a role. A substantial proportion of patients have a familial (autosomal dominant) pattern of inheritance; if a parent is a carrier there is a chance of transmission to a child, although whether and at what age the disorder appears is variable. Cases without a family history (sporadic) are also common. Increasing age is the main risk factor.
Symptoms
The tremor is bilateral and may be symmetrical or asymmetrical, with one hand more affected. It appears when the arms are held out (postural) and during movements such as bringing a cup to the mouth, holding a pen or writing (kinetic). Functional impact ranges from mild (unnoticed) to severe (inability to write, spilling food while eating, inability to hold a cup). Some patients also have a head tremor (a 'yes-yes' or 'no-no' type) or a voice tremor (shaky speech). Stress, fatigue and caffeine increase the tremor, whereas alcohol temporarily reduces it in many patients; this response can be a diagnostic clue but alcohol is not a treatment.
Diagnosis
The diagnosis of essential tremor is based mainly on the clinical history and neurological examination. Typical findings are a bilateral postural and/or kinetic tremor, the absence (or minimal presence) of resting tremor, and the absence of other neurological signs (bradykinesia, rigidity, ataxia). Drawing spirals and writing tests demonstrate the tremor. Brain MRI is usually normal and is performed mainly to exclude secondary causes in atypical or rapidly progressive cases. A DaTscan is helpful in cases where it is difficult to distinguish from Parkinson's disease. Thyroid function tests (to exclude hyperthyroidism) and, in younger patients, investigation for Wilson's disease may be needed. The differential diagnosis includes Parkinson's disease, physiological tremor (stress, caffeine, some drugs), dystonia and cerebellar tremor.
Medical (Conservative) Treatment
A mild tremor that does not impair function may not require treatment. When there is functional impairment, medication is the first step. Propranolol (a beta-blocker) and primidone (an anticonvulsant) are the main first-line options and reduce the tremor markedly in many patients; they can be used together when needed. Propranolol must be evaluated carefully in conditions such as asthma, COPD, heart block and low blood pressure. Primidone can cause transient nausea, unsteadiness and drowsiness with the first dose. Gabapentin and topiramate are alternative options. Botulinum toxin injection can help with head and voice tremor. Medications reduce the tremor but may not eliminate it completely.
Surgical and Interventional Treatments
Surgical and interventional methods are considered in cases that are resistant to medication and cause serious functional loss. Deep brain stimulation (DBS) is based on delivering high-frequency stimulation through electrodes placed in the ventral intermediate (VIM) nucleus of the thalamus and is particularly effective for hand tremor; because it is adjustable and reversible, it is preferred for bilateral treatment. MR-guided focused ultrasound (MRgFUS) is an incision-free alternative that creates a targeted ablation in the thalamus, is usually applied on one side, and may be an option for patients who prefer not to undergo surgery or who are at high risk. Ablative surgeries such as thalamotomy, used in the past, have largely been replaced by DBS. The choice of method is made according to the patient's age, cognitive status and preferences.
Prognosis
Essential tremor is a slowly progressive, chronic condition. In most patients the aim is a marked reduction in tremor rather than its complete disappearance; with medication and, where appropriate, DBS, functional improvement and an increase in quality of life can be achieved. The tremor returns if treatment is stopped, so management is usually long-term. In some older patients, other neurological signs may be added to the tremor over time. Outcomes vary from person to person and cannot be guaranteed in advance.
References
- Greenberg MS. Greenberg's Handbook of Neurosurgery. 10th ed. Thieme; 2023:1841.
- Winn HR, ed. Youmans Neurological Surgery. 6th ed. Saunders; 2011:933-941.
- Zesiewicz TA, Elble RJ, Louis ED, et al. Evidence-based guideline update: treatment of essential tremor. Report of the Quality Standards Subcommittee of the American Academy of Neurology. Neurology. 2011;77(19):1752-1755.
- Bhatia KP, Bain P, Bajaj N, et al. Consensus Statement on the classification of tremors. From the task force on tremor of the International Parkinson and Movement Disorder Society. Mov Disord. 2018;33(1):75-87.
This article is for general information and does not replace a medical examination. Diagnosis and treatment decisions are individual.