Essential Tremor

Definition

Essential tremor (ET) is a common neurological disorder characterised by involuntary and rhythmic shaking, typically affecting the hands, but it can also affect the head, voice, and other parts of the body. It is often more noticeable during voluntary movements such as eating, writing, or drinking.

Aetiology

The exact cause of essential tremor is not known, but it is believed to involve genetic and environmental factors. Approximately half of the cases are familial, suggesting a genetic predisposition. The disorder is often inherited in an autosomal dominant manner.

Pathophysiology

The pathophysiology of essential tremor is not completely understood. It is thought to involve abnormal communication between certain areas of the brain, including the cerebellum, thalamus, and cortex. This disruption may lead to the characteristic rhythmic shaking of essential tremor.

Risk factors

Family history of essential tremor
Age (more common in individuals over 40)

Signs and Symptoms

Involuntary, rhythmic shaking, particularly in the hands
Tremor that worsens with voluntary movement and stress
Difficulty with fine motor tasks (e.g., writing, drawing)
Head nodding or shaking
Voice tremor

Red Flags

Tremor associated with other neurological symptoms (e.g., weakness, changes in sensation)
Rapid onset of tremor
Tremor occurring in younger individuals without a family history

Investigations

Clinical history and physical examination, focusing on the characteristics of the tremor
Neurological examination to rule out other conditions (e.g., Parkinson's disease)
Blood tests to exclude metabolic causes (e.g., thyroid function tests)
Neuroimaging (MRI or CT scan) if there are atypical features or red flags

Management

Primary Care Management:

Propranolol (a beta-blocker) is often the first-line treatment, starting at 40 mg twice daily and titrating up as needed
Primidone (an anticonvulsant) may be used if propranolol is ineffective or contraindicated, starting at 50 mg at night and gradually increasing
Topiramate and gabapentin can be considered as alternative medications
Referral to a neurologist if symptoms are severe, not responsive to initial treatments, or if there are diagnostic uncertainties

Example Management for Essential Tremor:

A patient presenting with essential tremor may be started on propranolol 40 mg twice daily, increasing the dose gradually based on response and tolerability. If tremors persist despite optimal dosing, primidone may be introduced, starting at 50 mg at night and titrating up. The patient should be referred to a neurologist if symptoms significantly impact daily activities or if there is no improvement with first-line treatments.

References:

NICE. (2023). Essential Tremor: Management. Retrieved from https://cks.nice.org.uk/topics/tremor/management/
NHS. (2023). Essential Tremor. Retrieved from https://www.nhs.uk/conditions/essential-tremor/
National Institute of Neurological Disorders and Stroke (NINDS). (2023). Essential Tremor Information Page. Retrieved from https://www.ninds.nih.gov/Disorders/All-Disorders/Essential-Tremor-Information-Page
O'Sullivan, S. B., & Schmitz, T. J. (2016). Physical Rehabilitation. 6th ed. F.A. Davis Company.
Ropper, A. H., & Samuels, M. A. (2019). Adams and Victor's Principles of Neurology. 11th ed. McGraw-Hill Education.