Dystonia (generalised and focal) !

A movement disorder in which muscles contract on their own, twisting a body part into abnormal postures, such as the neck, eyelids or hand.

Updated 2026-11-01

Structures involved

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Why it happens

What it is

A movement disorder with sustained or intermittent involuntary muscle contractions that cause abnormal, often twisting and repetitive movements, postures or both. It is often triggered or worsened by voluntary action and may be relieved by a "sensory trick" (geste antagoniste). It can involve one body part (focal), adjacent parts (segmental) or the whole body (generalised). Common focal forms are cervical dystonia, blepharospasm, spasmodic dysphonia and writer's cramp.

Who gets it

Dystonia is the third most common movement disorder after essential tremor and Parkinson disease. Focal adult-onset dystonias are the most frequent, usually starting between 40 and 60 years; cervical dystonia and blepharospasm are more common in women. Generalised inherited forms usually begin in childhood. In Colombia and Latin America many cases are seen in neurology clinics; secondary dystonia from cerebral palsy, drugs and Wilson disease is also common.

Causes

Idiopathic or isolated focal dystonia in adults
Inherited forms: DYT1 (TOR1A) early-onset generalised dystonia, dopa-responsive dystonia (GCH1)
Drug-induced: acute dystonic reactions and tardive dystonia from dopamine-blocking drugs (antipsychotics, metoclopramide)
Brain injury: cerebral palsy, perinatal hypoxia, stroke, trauma, encephalitis
Neurodegenerative and metabolic diseases: Wilson disease, Parkinson disease, Huntington disease, progressive supranuclear palsy

Risk factors

Family history (autosomal dominant genes with reduced penetrance)
Exposure to dopamine receptor-blocking drugs
Repetitive skilled hand use (musicians, writers)
Perinatal brain injury
Female sex for cervical dystonia and blepharospasm

Pathophysiology

Dystonia is viewed as a network disorder involving the basal ganglia (mainly putamen and globus pallidus), cerebellum, thalamus and sensorimotor cortex. Loss of surround inhibition lets unwanted neighbouring muscles contract together with the intended ones (co-contraction and overflow). Abnormal sensorimotor integration and maladaptive plasticity explain why sensory tricks help and why highly practised tasks can trigger task-specific dystonias.

Classification

By body distribution: focal, segmental, multifocal, hemidystonia, generalised
By age at onset: childhood, adolescence, adult
By aetiology: isolated (genetic or idiopathic), combined with other movement disorders, acquired (drugs, brain injury)
Focal types: cervical dystonia (spasmodic torticollis), blepharospasm, oromandibular, laryngeal (spasmodic dysphonia), writer's cramp and musician's dystonia

Symptoms and signs

Cervical dystonia: head turning, tilting, forward or backward pulling, often with neck pain and head tremor
Blepharospasm: excessive blinking and forced eyelid closure, sometimes causing functional blindness
Writer's cramp: cramping and abnormal posture of the hand only while writing
Spasmodic dysphonia: strained, broken voice
Generalised dystonia: twisting of the trunk and limbs, often starting in a foot or leg in children
Improvement with a sensory trick, such as touching the chin or cheek
Worsening with stress and fatigue; disappears during sleep

Diagnosis

Clinical: Diagnosis is clinical, based on the pattern of abnormal postures and movements, sensory tricks and task specificity. A careful drug history is essential.
Tests: Slit-lamp examination for Kayser-Fleischer rings, serum ceruloplasmin and urinary copper in anyone with onset before about 50 years to exclude Wilson disease. Genetic testing in early-onset or familial cases. A trial of levodopa in childhood-onset dystonia to detect dopa-responsive dystonia.
Imaging: Brain MRI in acquired, unilateral, rapidly progressive or combined forms, looking for basal ganglia lesions, stroke or metal deposition. MRI is normal in most isolated dystonias.

Differential diagnosis

Musculoskeletal torticollis (sternocleidomastoid fibrosis, atlantoaxial subluxation)
Tics (Tourette syndrome)
Essential tremor and parkinsonism
Functional (psychogenic) dystonia
Hemifacial spasm and myokymia (eyelid)
Focal seizures

Goal of treatment

Reduce involuntary contractions, pain and disability and improve posture and function; treat the cause when one is found.

Treatment

Procedure: Botulinum toxin injections into the overactive muscles are first-line for focal dystonias such as cervical dystonia, blepharospasm and spasmodic dysphonia, repeated every few months.
Medical: Oral anticholinergics (trihexyphenidyl) mainly in young patients with generalised dystonia; benzodiazepines and baclofen as adjuncts. Every child with dystonia deserves a levodopa trial for dopa-responsive dystonia. Acute drug-induced dystonia responds rapidly to parenteral anticholinergic or antihistamine drugs.
Surgical: Deep brain stimulation of the globus pallidus internus for disabling generalised, segmental or refractory cervical dystonia, especially DYT1 dystonia.
Rehabilitation: Physiotherapy, sensory retraining, speech therapy for dysphonia and occupational adaptations for task-specific dystonia.
Follow-up: Nursing priorities in status dystonicus: airway, temperature, hydration, CK and kidney function, and pain control in intensive care.

Complications

Chronic neck pain and cervical spine degeneration with radiculopathy
Functional blindness in severe blepharospasm
Swallowing and speech problems
Contractures and scoliosis in generalised dystonia
Status dystonicus with rhabdomyolysis and kidney failure
Depression, anxiety and social isolation

Prognosis

Adult-onset focal dystonias rarely spread beyond one or two adjacent regions and often respond well to botulinum toxin; spontaneous remissions occur in a minority of cervical dystonia cases. Childhood-onset forms more often generalise. Dopa-responsive dystonia has an excellent outcome with treatment.

Prevention

Cautious use of dopamine-blocking drugs and early recognition of drug reactions
Genetic counselling in inherited forms

Test yourself

Think of the answer, then tap the question to see it.

A patient's head turns involuntarily to one side and improves when she touches her chin. What is this and what is the sign called?

Cervical dystonia; the relief from touch is a sensory trick (geste antagoniste).

What is first-line treatment for most focal dystonias?

Botulinum toxin injections into the affected muscles.

Which treatable disease must be excluded in dystonia beginning before about age 50?

Wilson disease (ceruloplasmin, urinary copper and slit-lamp examination).

Which drug test should every child with dystonia receive?

A levodopa trial, to detect dopa-responsive dystonia.

Which deep brain stimulation target is used for refractory dystonia?

The globus pallidus internus.

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Educational information, not medical advice. For any symptom, see a health professional.

Sources: Dystonia | MedlinePlus (MedlinePlus (U.S. National Library of Medicine), 2025).

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Representative model, for educational purposes only.

Putamen highlighted on the Durgical 3D model