Involuntary movements (dyskinesias) include dystonia, chorea, athetosis, hemiballismus, myoclonus and tic.
Involuntary movements are often caused by an injury or disorder in the extrapyramidal system or are associated with degenerative brain disease.
Their aetiology is often unknown. Some patients have an underlying adverse drug effect, some a genetic cause, and a careful family history must therefore be taken.
Blood glucose, liver and thyroid values should be checked in primary health care.
Involuntary movements are often treatment resistant.
Dystonia
Dystonia is characterized by abnormal muscle tension causing malposition and jerky movements.
Based on their distribution, dystonias can be divided into focal, segmental, multifocal and generalized dystonias and hemidystonia.
Dystonia may be isolated or associated with another neurological symptom.
Focal dystonia
Occurs in just one area of the body.
Cervical dystonia appears in the neck-shoulder region, causing the head to turn to one side, tilt and/or jerk. The symptom may be associated with tremor or neck pain.
Blepharospasm is a bilateral compulsive need to blink or close the eyes.
Oromandibular dystonia affects the mouth, jaw or masticatory muscles. Compulsive movements of the mouth and jaw area are typical for oromandibular dystonia.
Spasmodic dysphonia, or laryngeal dystonia, is contraction of laryngeal muscles causing strained phonation or voice stoppages.
Task-specific dystonias are dystonias occurring in association with certain movements. The most common example of these is writer's cramp (mogigraphia). Similar symptoms may be seen in musicians, e.g. in piano or guitar players (musician's cramp).
They often develop when practising a precise, repetitive movement. Instrumental examinations do not show anything abnormal.
Involuntary unilateral twitching of facial muscles, sometimes involving one half of the face (not formally classified as dystonia).
Possible aetiological factors include the sequelae of facial palsy Peripheral Facial Paralysis, degeneration of the facial nerve or its compression by blood vessels in the brain stem area.
Generally caused by damage to the subthalamic nucleus or its nearby area, most commonly as a result of cerebral infarction. In such cases, the onset of symptoms is acute, and patients are usually elderly.
Hyperglycaemia may be associated with hemiballismus and chorea.
The ballistic movements affect the proximal muscles of the upper and lower extremities; the limbs are flung in a wide motion.
Treatment: haloperidol 1-2 mg three times daily will provide reasonable relief. Valproate 800-1 200 mg/day might be effective in some cases.
Generally, hemiballismus subsides within a few weeks from the cerebral event; however, symptoms may also persist.
Chorea and athetosis
Chorea denotes rapid arrhythmic movements and athetosis denotes distal writhing, "wormlike" involuntary movements. When they occur together, the condition is called choreoathetosis.
Choreoathetosis may be associated with cerebral palsy with basal ganglia involvement.
Sydenham's chorea occurs as a sequela of streptococcal infection and is an arteritis affecting the minor arteries of the basal ganglia region. The patients are children or adolescents. The disorder may be accompanied by rheumatic fever or carditis.
Huntington's disease (formerly Huntington's chorea, see Parkinson's Disease Dementia and Dementia with Lewy Bodies) is a dominantly inherited disease, causing progressive memory disorder with onset typically at middle age and chorea of variable severity. The chorea causes an arrhythmic, peculiar walking style typical for the condition.
Tardive dyskinesia associated with the use of antipsychotic drugs (see below) and the dyskinesia caused by dopaminergic drugs (see below) are mostly choreatic.
Autoimmune encephalitis has been found to be associated with chorea, dyskinesia and dystonia. Particularly if dyskinesia is associated with a decreased level of consciousness and other symptoms of encephalopathy, the patient may have NMDA receptor encephalitis.
There are often also other symptoms, such as ataxia, epilepsy and neuropsychiatric symptoms. Changes are commonly seen in cerebral MRI.
Tetrabenazine may alleviate chorea (its official indication is chorea in Huntington's disease). Haloperidol has also been used with good response.
In restless legs syndrome the patient has an unpleasant sensation or pain in the lower limbs, particularly at bedtime. The patient often needs to get out of bed to walk around.
The symptoms are either primary or may be associated with iron deficiency, uraemia, pregnancy or neuropathy.
In patients with long-standing Parkinson's disease levodopa often causes choreoathetoid movements (dyskinesias, see Parkinson's Disease) and painful muscle cramps (dystonias).
Antipsychotic drugs
The use of antipsychotics (including metoclopramide, prochlorperazine) is associated with several types of movement disorders.
Acute dystonia develops at the beginning of the drug treatment. Contortion of the extremities, head, face and eyes into unusual, even painful positions is characteristic. The condition is most common in young males.
The patient should avoid the drug that caused the condition.
Drug-induced parkinsonism Parkinson's Disease is common when large doses of antipsychotics are used. The condition is dose-dependent and generally reversible.
Akathisia Restless Legs and Akathisia is drug-induced motor restlessness; there is chiefly a compulsive need to move.
The most common agents inducing akathisia are antipsychotics (one in five users of traditional antipsychotics) and metoclopramide, sometimes also antidepressants.
Akathisia must be differentiated from restless legs (see above), where the patient finds it difficult to lie down and sleep. In akathisia the patient typically walks on the spot and finds it difficult to remain sitting still.
Reducing the dose or changing to a more suitable medication will relieve the symptoms. Alternative medication includes the second-generation antipsychotics (e.g. risperidone, olanzapine, quetiapine, clozapine).
Tardive dyskinesia is the most difficult movement disorder associated with antipsychotics, because it may become permanent. The symptoms are due to drug-induced dopamine receptor blockade.
In general, the syndrome develops after years of treatment with an antipsychotic agent, but it has been described as little as after six months of treatment.
The risk of tardive dyskinesia associated with the use of second-generation antipsychotics is apparently lower than with traditional antipsychotics.
The most typical manifestations are involuntary movements around the mouth, but the limbs and trunk can also be affected.
Typically, the symptoms appear or get worse when the dose of the antipsychotic is decreased. The elderly and female patients are at greater risk.
Other possible tardive phenomena include stereotypies, myoclonus, tremor, tic, parkinsonism, eye movement disordes and respiratory dyskinesia.
Treatment
If possible, antipsychotic medication should be withdrawn or be replaced with a second-generation antipsychotic drug if the patient is using a traditional one. After withdrawal, the involuntary movements initially often intensify but may gradually disappear over several weeks or months.
The most important remedy is prevention: i.e. avoidance of prolonged treatment with antipsychotics.
Paroxysmal dyskinesias
Recurrent paroxysmal dyskinesias without loss of consciousness
There is often an identifiable triggering factor.
Classification
Paroxysmal kinesigenic dyskinesia (PKD)
Paroxysmal non-kinesigenic dyskinesia (PNKD)
Paroxysmal exercise-induced dyskinesia (PED)
These differ in terms of the duration and frequency of attacks and triggering factors.
The attacks are of short duration and consist variably of choreoathetosis, dystonia and ballism.
Paroxysmal dyskinesias are often benign and respond to medication and to avoiding the triggering factor.
Other involuntary movements
Myoclonus denotes a brief muscle contraction. It may be physiological, e.g., jerks on falling asleep and hiccups (see Hiccup). It may be a familial phenomenon or it may be related to a number of neurological disorders, such as progressive myoclonal epilepsy and Creutzfeldt-Jakob's disease. Levetiracetam, valproate and clonazepam have been used for symptomatic treatment.
The opsoclonus myoclonus syndrome has been seen as a rare sequela of COVID-19. It involves irregular eye movements and sometimes ataxia in addition to myoclonus.
A tic is a brief, compulsive, stereotypic movement, most often in the face or neck. It may be associated with Tourette's syndrome Tic Disorders in Childhood. In contrast to chorea, tics can be transiently controlled Tic Disorders in Childhood.
Various types of tremor TremorEssential Tremor are also classified as movement disorders.
References
Krack P, Volkmann J, Tinkhauser G et al. Deep Brain Stimulation in Movement Disorders: From Experimental Surgery to Evidence-Based Therapy. Mov Disord 2019;34(12):1795-1810. [PubMed]
Chen C, Zheng H, Yang L et al. Chorea-ballism associated with ketotic hyperglycemia. Neurol Sci 2014;35(12):1851-5. [PubMed]
Hawley JS, Weiner WJ. Hemiballismus: current concepts and review. Parkinsonism Relat Disord 2012;18(2):125-9. [PubMed]
Balint B, Vincent A, Meinck HM et al. Movement disorders with neuronal antibodies: syndromic approach, genetic parallels and pathophysiology. Brain 2018;141(1):13-36. [PubMed]
Emamikhah M, Babadi M, Mehrabani M et al. Opsoclonus-myoclonus syndrome, a post-infectious neurologic complication of COVID-19: case series and review of literature. J Neurovirol 2021;27(1):26-34. [PubMed]