Benign Essential Tremor

Definition/diagnostic criteria Benign essential tremor (BET), also known as essential tremor (ET), is a neurological disorder characterised by rhythmic, involuntary shaking of a part of the body, most commonly the hands. It can also affect the head, voice and other body parts. Usually, the tremor is bilateral and other neurological signs are absent. Diagnosis is primarily clinical, based on the observation of tremor characteristics and the exclusion of other causes.

Epidemiology BET is one of the most common movement disorders. Its prevalence increases with age, affecting up to 4% of individuals aged ≥40. It is more prevalent in individuals with a family history of tremor, suggesting a genetic component. The condition affects both sexes equally.

Diagnosis
Clinical features: BET usually presents as a postural or kinetic tremor, affecting the hands and forearms symmetrically.

It can also involve the head (nodding or shaking), voice (quivering), and less commonly, the lower limbs. Stress, fatigue, and stimulants can exacerbate the tremor, whereas alcohol typically eases it. Importantly, the tremor typically spares the patient during rest (which helps distinguish it from Parkinson’s disease).

Investigations: Diagnosis is primarily clinical. However, when the clinical picture is unclear, further investigations may be considered.

This might include thyroid function tests to exclude hyperthyroidism, and in some cases, brain imaging to rule out other neurological conditions. The characteristic abnormalities in BET include postural and action tremors without pathological findings on neurological imaging.

Treatment The management of BET involves both pharmacological and non-pharmacological approaches.

• First-line pharmacological treatments include propranolol and primidone.
• Other drugs such as topiramate and gabapentin may be considered for patients who do not respond to or cannot tolerate first-line treatments.
• Non-pharmacological interventions include lifestyle changes, such as reducing caffeine intake and avoiding stress triggers.
• In severe cases, where pharmacotherapy is ineffective, surgical options such as deep brain stimulation may be considered.

Prognosis BET is a progressive condition, but the rate of progression varies significantly between individuals. While it is not a life-threatening condition, it can lead to significant functional impairment and affect the quality of life, especially in severe cases. Early intervention and appropriate management can help to control symptoms and improve the quality of life for those affected.