Dyskinesia refers to a category of

movement disorder Movement disorder refers to any clinical syndrome with either an excess of movement or a paucity of voluntary and involuntary movements, unrelated to weakness or spasticity. Movement disorders are synonymous with basal ganglia or extrapyramidal ...

s that are characterized by involuntary muscle movements, including movements similar to

tic A tic is a sudden, repetitive, nonrhythmic motor movement or vocalization involving discrete muscle groups.American Psychiatric Association (2000)DSM-IV-TR: Tourette's Disorder.''Diagnostic and Statistical Manual of Mental Disorders'', 4th ed., ...

s or

chorea Chorea (or choreia, occasionally) is an abnormal involuntary movement disorder, one of a group of neurological disorders called dyskinesias. The term ''chorea'' is derived from the grc, χορεία ("dance"; see choreia), as the quick movem ...

and diminished voluntary movements. Dyskinesia can be anything from a slight tremor of the hands to an uncontrollable movement of the upper body or lower extremities. Discoordination can also occur internally especially with the respiratory muscles and it often goes unrecognized. Dyskinesia is a symptom of several

medical disorder A disease is a particular abnormal condition that negatively affects the structure or function of all or part of an organism, and that is not immediately due to any external injury. Diseases are often known to be medical conditions that a ...

s that are distinguished by their underlying cause.

Types

Medication-induced dyskinesias

Acute dystonia is a sustained muscle contraction that sometimes appears soon after administration of

antipsychotic Antipsychotics, also known as neuroleptics, are a class of psychotropic medication primarily used to manage psychosis (including delusions, hallucinations, paranoia or disordered thought), principally in schizophrenia but also in a range of ...

medications. Any muscle in the body may be affected, including the jaw, tongue, throat, arms, or legs. When the throat muscles are involved, this type of dystonia is called an acute

laryngospasm Laryngospasm is an uncontrolled or involuntary muscular contraction (spasm) of the vocal folds. The condition typically lasts less than 60 seconds, but in cases partial blocking it may last 20 to 30 minutes and hinder inspiration, while exhala ...

and is a medical emergency because it can impair breathing. Older antipsychotics such as

Haloperidol Haloperidol, sold under the brand name Haldol among others, is a typical antipsychotic medication. Haloperidol is used in the treatment of schizophrenia, tics in Tourette syndrome, mania in bipolar disorder, delirium, agitation, acute psychosi ...

Fluphenazine Fluphenazine, sold under the brand name Prolixin among others, is a high-potency typical antipsychotic medication. It is used in the treatment of chronic psychoses such as schizophrenia, and appears to be about equal in effectiveness to low-pote ...

are more likely to cause acute dystonia than newer agents. Giving high doses of antipsychotics by injection also increases the risk of developing acute dystonia. Methamphetamine, other

amphetamines Substituted amphetamines are a class of compounds based upon the amphetamine structure; it includes all derivative compounds which are formed by replacing, or substituting, one or more hydrogen atoms in the amphetamine core structure with sub ...

and dopaminergic stimulants including

cocaine Cocaine (from , from , ultimately from Quechua: ''kúka'') is a central nervous system (CNS) stimulant mainly used recreationally for its euphoric effects. It is primarily obtained from the leaves of two Coca species native to South Ameri ...

and

pemoline Pemoline, sold under the brand name Cylert among others, is a stimulant medication which has been used in the treatment of attention-deficit hyperactivity disorder (ADHD) and narcolepsy. It has been discontinued in most countries to due to rare ...

can produce choreoathetoid dyskinesias; the prevalence, time-frame and prognosis are not well established. Amphetamines also cause a dramatic increase in choreoathetoid symptoms in patients with underlying

such as Sydenham's, Huntington's, and Lupus. Long-term use of amphetamines may increase the risk of Parkinson's disease (PD): in one

retrospective study A retrospective cohort study, also called a historic cohort study, is a longitudinal cohort study used in medical and psychological research. A cohort of individuals that share a common exposure factor is compared with another group of equival ...

with over 40,000 participants it was concluded that amphetamine abusers generally had a 200% higher chance of developing PD versus those with no history of abuse; the risk was much higher in women, almost 400%. There remains some controversy as of 2017.

Levodopa-induced dyskinesia Levodopa-induced dyskinesia (LID) is a form of dyskinesia associated with levodopa (l-DOPA), used to treat Parkinson's disease. It often involves hyperkinetic movements, including chorea, dystonia, and athetosis. In the context of Parkinson's dis ...

(LID) is evident in patients with Parkinson's disease who have been on levodopa () for prolonged periods of time. LID commonly first appears in the foot, on the most affected side of the body. There are three main types that can be classified on the basis of their course and clinical presentation following an oral dose of : * Off-period dystonia – correlated to the

akinesia Hypokinesia is one of the classifications of movement disorders, and refers to decreased bodily movement. Hypokinesia is characterized by a partial or complete loss of muscle movement due to a disruption in the basal ganglia. Hypokinesia is a sym ...

that occurs before the full effect of sets in, when the plasma levels of are low. In general, it occurs as painful spasms in the foot. Patients respond to therapy. * Diphasic dyskinesia – occurs when plasma L-DOPA levels are rising or falling. This form occurs primarily in the lower limbs (though they can happen elsewhere) and is usually dystonic (characterized by apparent rigidity within muscles or groups thereof) or

ballistic Ballistics may refer to: Science * Ballistics, the science that deals with the motion, behavior, and effects of projectiles ** Forensic ballistics, the science of analyzing firearm usage in crimes ** Internal ballistics, the study of the proc ...

(characterized by involuntary movement of muscles) and will not respond to dosage reductions. * Peak-dose dyskinesia – the most common form of levodopa-induced dyskinesia; it correlates with the plateau plasma level. This type usually involves the upper limbs more (but could also affect the head, trunk and respiratory muscles), is choreic (of chorea), and less disabling. Patients will respond to reduction but may be accompanied by deterioration of

parkinsonism Parkinsonism is a clinical syndrome characterized by tremor, bradykinesia (slowed movements), rigidity, and postural instability. These are the four motor symptoms found in Parkinson's disease (PD), after which it is named, dementia with Lewy b ...

. Peak-dose L-DOPA-induced dyskinesia has been suggested to be associated with cortical dysregulation of dopamine signaling.

Chronic or tardive

Late-onset dyskinesia, also known as

tardive dyskinesia Tardive dyskinesia (TD) is a disorder that results in involuntary repetitive body movements, which may include grimacing, sticking out the tongue or smacking the lips. Additionally, there may be rapid jerking movements or slow writhing movemen ...

, occurs after long-term treatment with an

drug such as

haloperidol Haloperidol, sold under the brand name Haldol among others, is a typical antipsychotic medication. Haloperidol is used in the treatment of schizophrenia, tics in Tourette syndrome, mania in bipolar disorder, delirium, agitation, acute psychosi ...

(Haldol) or

amoxapine Amoxapine, sold under the brand name Asendin among others, is a tricyclic antidepressant (TCAs). It is the N-demethylated metabolite of loxapine. Amoxapine first received marketing approval in the United States in 1992 (approximately 30 to 40 ...

(Asendin). The symptoms include tremors and writhing movements of the body and limbs, and abnormal movements in the face, mouth, and tongue including involuntary lip smacking, repetitive pouting of the lips, and tongue protrusions.

Rabbit syndrome Rabbit syndrome is a rare form of extrapyramidal side effect of antipsychotic drugs in which perioral tremors occur at a rate of approximately 5 Hz. Rabbit syndrome is characterized by involuntary, fine, rhythmic motions of the mouth along a ...

is another type of chronic dyskinesia, while orofacial dyskinesia may be related to persistent replication of Herpes simplex virus type 1.

Non-motor

Two other types,

primary ciliary dyskinesia Primary ciliary dyskinesia (PCD) is a rare, autosomal recessive genetic ciliopathy, that causes defects in the action of cilia lining the upper and lower respiratory tract, sinuses, Eustachian tube, middle ear, Fallopian tube, and flagella of sper ...

and biliary dyskinesia, are caused by specific kinds of ineffective movement of the body, and are not

References

Works cited

External links

{{Nervous and musculoskeletal system symptoms and signs Symptoms and signs: Nervous system Parkinson's disease Neurological disorders Extrapyramidal and movement disorders