Tremors

A tremor is an involuntary, rhythmic shaking of a part of the body. It is a symptom rather than a diagnosis on its own, and it can have many different causes, some requiring no treatment at all, others reflecting a specific neurological condition.

Essential tremor is the most common movement disorder. It produces a rhythmic shaking, most often affecting the hands, though it can also involve the head, voice or legs. Unlike Parkinson’s disease, the shaking of essential tremor typically appears during activity rather than at rest (for example, while writing, holding a cup or bringing a spoon to the mouth).

Essential tremor is frequently hereditary, and many patients can identify a parent or grandparent with similar symptoms. It tends to worsen with movement, stress, fatigue and caffeine.

Essential tremor is sometimes described as “benign,” a word that can undersell its impact. It does not shorten life, but a tremor severe enough to prevent someone from signing their name, eating comfortably in public, or holding a phone to their ear can meaningfully affect daily life and confidence.

Because “tremor” describes many different conditions, identifying the underlying cause correctly is an essential first step, as different types of tremors respond to different treatments.

Tremor can also occur as a symptom of other, sometimes reversible, conditions, including cerebellar tremor (related to the brain’s coordination centre), physiological tremor (exaggerated by stress, fatigue, low blood sugar or an overactive thyroid), drug-induced tremor (a side effect of certain medications), and orthostatic tremor (a rare disorder that appears only on standing). Correctly identifying which type of tremor is present is a core part of evaluation.

Most patients with essential tremor are managed successfully with medication or simply monitor mild symptoms without treatment. A surgical evaluation is generally considered for patients whose tremor:

• Has not responded adequately to appropriate trials of medication
• Is significantly interfering with daily activities such as eating, writing, dressing or working
• Is affecting quality of life and confidence in social or professional situations

Surgical or device-based treatment is typically considered once first-line options have been tried without adequate benefit:

• Medication: propranolol and primidone are the established first-line treatments
• Botulinum toxin injections: an option in selected cases, particularly for head and voice tremor
• Physical therapy and assistive devices: including weighted utensils and adapted pens

When these measures no longer provide adequate control, two surgical options are generally discussed:

• MRgFUS: an incisionless treatment for medication-resistant tremor, usually performed on one side
• DBS: generally considered for moderate to severe tremor that has not responded to medication, particularly where both hands are significantly affected

Both DBS and MRgFUS target a small structure deep in the brain (the thalamus) involved in generating tremor. DBS uses an implanted, adjustable electrode connected to a pulse generator; MRgFUS creates a small, precisely placed lesion using focused ultrasound energy, without any incision or implant. The two procedures are described in detail on our Deep Brain Stimulation and MRgFUS pages, including guidance on how the choice between them is usually made.

• Detailed history, including family history and the pattern of when the tremor appears
• Neurological examination and standardized tremor rating
• Assessment of the impact on specific daily tasks
• High-resolution brain MRI; CT imaging where MRgFUS is being considered, to measure skull density (a factor that affects whether ultrasound can be focused effectively)
• Blood tests to exclude reversible causes, such as thyroid dysfunction

Both DBS and MRgFUS aim to meaningfully reduce tremor in the treated limb and improve the ability to carry out everyday tasks. Neither treatment is intended to eliminate every trace of tremor in all circumstances, and the degree of improvement varies between patients.

Each treatment carries its own risk profile, discussed in detail on the relevant procedure page. In general terms, DBS carries surgical risks associated with implanted hardware but is reversible and adjustable, while MRgFUS avoids implants and incisions but creates a permanent lesion, meaning that any persistent side effect cannot be reversed by adjusting a device.

Recovery, follow-up and, for DBS, programming are described on the respective treatment pages. Both pathways involve structured follow-up to assess benefit and manage any side effects.