# Tremor and Movement Disorders

> Tremor and movement disorders for NEET-PG Medicine covering chorea, dystonia, myoclonus, tics and hemiballismus, localised by site and clinical pattern.

- Canonical URL: https://prepelephant.com/topics/neet-pg/medicine/tremor-and-movement-disorders
- Exam / course: NEET-PG · Subject: Medicine
- Publisher: PrepElephant (https://prepelephant.com) — Prepared and reviewed by the PrepElephant Academic Review Team
- First published: 2026-10-08
- Last updated: 2026-10-08
- Reference basis: Adams and Victor's Principles of Neurology; Bradley's Neurology in Clinical Practice; Harrison's Principles of Internal Medicine
- How to cite: "Tremor and Movement Disorders", PrepElephant, https://prepelephant.com/topics/neet-pg/medicine/tremor-and-movement-disorders

## Direct answer

Tremor and movement disorders are classified by the pattern of abnormal movement and by the site of the lesion that produces it. Rest tremor suggests Parkinson disease, action tremor suggests essential tremor, and intention tremor suggests cerebellar disease. Chorea and dystonia arise from striatal and pallidal circuits, hemiballismus from a contralateral subthalamic lesion, and myoclonus and tics from cortical or subcortical circuits.

## What you must remember

- **Rest tremor:** a 4 to 6 Hz pill-rolling tremor that lessens with voluntary movement, typical of Parkinson disease.
- **Action tremor:** postural and kinetic tremor that worsens with movement and improves with a small amount of alcohol, typical of essential tremor.
- **Intention tremor:** tremor that worsens as the target is approached, with dysmetria, from cerebellar lesions.
- **Chorea:** irregular, flitting movements from striatal disease, seen in Huntington disease, Sydenham chorea and levodopa toxicity.
- **Dystonia:** sustained or patterned contractions from putaminal and pallidal disease, improved by a sensory trick and responsive to botulinum toxin.
- **Myoclonus:** brief, shock-like jerks from cortical or brainstem sources, seen in Creutzfeldt-Jakob disease.
- **Tics:** brief, suppressible movements preceded by a premonitory urge, typical of Tourette syndrome.
- **Hemiballismus:** violent flinging movements of one limb from a contralateral subthalamic nucleus lesion, most often a small stroke.

## A localisation pathway for an unfamiliar involuntary movement

A 24-year-old man develops a tremor, a fixed posture of the hand and a change in mood over a year, with a history of liver disease. Work through the movement in five steps, narrowing the site before accepting a label.

1. **Describe the movement precisely:** Note whether it is rhythmic or irregular, at rest or on action, present in sleep or not (most involuntary movements fade in sleep), and whether a sensory trick changes it.
2. **Suspect Wilson disease in young dystonia:** A fixed, twisting posture that improves with touching the chin is dystonia, which in a young adult prompts a search for Wilson disease. Low serum ceruloplasmin, raised 24-hour urinary copper and slit-lamp examination for Kayser-Fleischer rings form the initial screen, with liver tests and MRI for basal ganglia change.
3. **Review the drug history:** A tremor in a patient with a history of antipsychotic use needs a drug review, because acute dystonia and tardive dyskinesia are drug-induced. Metoclopramide blocks striatal dopamine receptors and carries the same risk.
4. **Test for essential tremor:** A tremor that is postural, familial and improved by alcohol points to essential tremor, where propranolol or primidone are the usual first drugs.
5. **Localise the site:** Each step narrows the localisation from striatum to cerebellum to cortex.

## Where the examiner tests localisation rather than names

The most frequent error is naming a movement by its look rather than its site.

- **Trap:** naming a tremor from its appearance alone, such as calling an intention tremor Parkinson disease — **Correct:** a tremor at rest and one on action are opposite clues, and an intention tremor points to the cerebellum even when it looks like Parkinson disease.
- **Trap:** confusing myoclonus with tremor — **Correct:** myoclonus is a brief jerk that a sudden movement or stimulus can trigger, while tremor is rhythmic.
- **Trap:** assuming tics and chorea behave alike — **Correct:** tics are briefly suppressible and preceded by a premonitory urge, whereas chorea and dystonia cannot be voluntarily suppressed, which is a classic viva point.
- **Trap:** accepting a psychiatric or drug label for dystonia with liver disease — **Correct:** a young patient with dystonia and liver disease should prompt a check for Wilson disease first.

Hemiballismus is a stroke syndrome of older patients, so the examiner expects the subthalamic nucleus to be named rather than the striatum.

## Frequently asked questions

### What is the difference between rest tremor and essential tremor?

Rest tremor is a 4 to 6 Hz tremor that is most obvious at rest and lessens with action, typical of Parkinson disease. Essential tremor is a postural and kinetic tremor that appears on action, often improves with a small amount of alcohol, and responds to propranolol or primidone.

### Which investigation screens for Wilson disease in a young patient with dystonia?

Wilson disease in a young patient with dystonia is screened with serum ceruloplasmin, 24-hour urinary copper and slit-lamp examination for Kayser-Fleischer rings. Liver function tests and MRI, which may show basal ganglia signal change, support the diagnosis and guide the next steps.

### Why is metoclopramide linked to tardive dyskinesia?

Metoclopramide is linked to tardive dyskinesia because it blocks dopamine D2 receptors in the striatum, as antipsychotic drugs do. Prolonged use, particularly in older patients, can produce orofacial dyskinesia that may persist after the drug is stopped.

### Which movement disorder follows a stroke in the subthalamic nucleus?

Hemiballismus follows a stroke or haemorrhage in the contralateral subthalamic nucleus, producing violent flinging movements of one limb. It often settles over weeks, but dopamine-blocking drugs may be used if the movements are severe.