Dyskinesia can be a stand-alone condition. However, typically, it is associated with brain injury, antipsychotic medications, or the long-term use of levodopa, a drug involved in the management of Parkinson's disease.
Treating dyskinesia usually involves medications or surgically repairing the underlying cause.
- Dyskinesia symptoms start out as minor shakes, tics, or tremors, usually in someone's dominant hand or foot.
- The many types of dyskinesia are associated with separate sets of causes.
- In many cases, it is not treated unless symptoms are severe.
- Where caused by disorders like autism, behavioral therapy may also be helpful.
The most common cause of dyskinesia is damage or injury to the brain.
Involuntary movement is the chief symptom of dyskinesia.
Symptoms worsen gradually over time, although they can develop suddenly or intensify following brain damage or injury.
Each type of dyskinesia causes specific symptoms that are normally unique so that the different kinds can be distinguished.
The cause of dyskinesia is almost always altered brain chemistry, or brain damage, specifically, injury to the region of the brain called the basal ganglia where voluntary movement and learned habits are controlled.
The preferred course of treatment for each type of dyskinesia largely depends on the reason for the change that has occurred in the brain.
Common types of dyskinesia include:
Levodopa-induced or Parkinson's dyskinesia
An estimated 50 percent of people with Parkinson's disease who are being treated with levodopa develop dyskinesia within 4–5 years.
Common symptoms include:
- writhing or wriggling
- head bobbing
About half of those with levodopa-induced dyskinesia (LID) do not find their symptoms troublesome enough to treat.
A common symptom of Parkinson's disease is tremors in the hands.
Tremors are defined by a rhythmic movement. Common types of tremor include:
- Static or resting: When tremors occur in a relaxed, resting, and fully supported limb. It is usually associated with Parkinson's disease and multiple sclerosis (MS).
- Kinetic or action and intention: This is when tremors occur during movement of an upper body part, normally the arm or hand. It is usually associated with MS, vascular disease, tumors, and cerebellar degeneration conditions.
- Postural: This type is when tremors happen while a limb is not being moved and that continue once it is moved. Postural tremors are caused by physiological factors, such as alcohol abuse, antidepressants, and heavy metal poisoning. They can also be caused by neurological conditions, for example, Wilson's disease.
Dystonia is defined as sustained muscle contractions, often involving repetitive, abnormal twisting movements or postures.
Some people with dystonia also experience blepharospasms, or continuous, involuntary blinking, and writer's cramp or an inability to write because of an abnormal arm or hand posture.
Chorea is defined by continuous, sudden, jerky movements that are each held for a few seconds. The limbs, head, and face are commonly affected. Symptoms can occur on one side of the body, or alternate between both sides randomly.
Chorea is usually a side effect of certain medications. Those known to cause chorea include:
- antiepileptic medications
- Parkinson's medications
- antipsychotic medications
A person can also acquire chorea. Causes of acquired chorea include:
- rheumatic fever
- Lyme disease
- bacterial endocarditis
- Creutzfeldt-Jakob disease (CJD)
- pregnancy or hormone replacement therapy
- childhood cardiac surgery
- severe vitamin B-1 and B-12 deficiency
- most toxins
- conditions affecting the central nervous system, for example, cerebral palsy
Tardive or delayed dyskinesia
Medication for conditions such as bipolar disorder and schizophrenia may cause dyskinesia as a side effect.
These medications work by blocking dopamine, which interrupts cellular communication.
Older antipsychotics are thought to cause more of a risk of dyskinesia than newer ones. They include:
Random, uncontrollable symptoms of tardive dyskinesia include:
- rapid blinking
- waving of the arms or hands
- sticking out the tongue
- random movement of the lips, tongue, or jaw
- sometimes movement in the limbs, fingers, and toes
- swaying movements of the hips or torso in severe cases
- difficulty breathing, also in severe cases
Individuals with schizophrenia specifically were 31.2 times more likely to develop the condition.
Additional factors that increase the risk of tardive dyskinesia include:
- being female
- being over 55 years of age
- being of Asian or African-American heritage
- the abuse of drugs and alcohol
This type of dyskinesia is defined by sudden, usually repetitive, muscle spasms and jerks.
Myoclonus types of dyskinesia cause symptoms that are severe enough to be disabling.
Common types of myoclonus dyskinesia include:
- Progressive myoclonic encephalopathy.
- Static myoclonic encephalopathy, normally caused by oxygen cutoff to the brain.
- Myoclonic epilepsies, normally affecting older women with symptoms limited to one part of the body, often the face.
- Benign essential myoclonus, where symptoms usually begin in childhood or adolescence and affect most of the body, causing spasms up to 50 times per minute.
This type is defined by abnormal twisting of the neck and head, usually tipping the head in one direction and rotating the chin the opposite way. It is caused by a shortened sternocleidomastoid muscle and can develop at any age.
Ballism is defined by wild, often violent throwing or flinging of the arms or legs.
Depending on their severity, spasms may be powerful enough to cause mild to severe injury, predominately shoulder, hip, or knee dislocation.
Ballism normally affects multiple limbs and both sides of the body. Hemiballism affects just one side or limb.
All types of ballism are typically caused by cerebrovascular events that include brain injury, asphyxia (suffocation), or stroke.
This type is defined by slow, turning, curving, or bending, writhing movements, most often in the fingers, toes, and hands. The tongue, arms, legs, and neck can also be affected.
Athetosis is usually caused by brain damage, specifically caused by a lack or loss of oxygen or blood supply.
Stereotypies and tics
These dyskinesia are defined by stereotyped or repetitive, useless movements or muscle twitches. An individual may have some initial level of control over these movements, even an ability to reduce them.
Because of this, some medical professionals do not consider stereotypies and tics to be a type of dyskinesia.
Depending on the severity, the symptoms of stereotypies and tics range from mildly irritating to disabling. Types include:
- Simple tic: Defined by a sudden rapid muscle twitch in the same spot.
- Common motor stereotypies: Defined by repetitive, aimless but often ritualized motions.
- Complex, multiple tics or stereotypies: Defined by extensive severe tics or twitches. Especially when associated with Tourette's syndrome, symptoms may include random, inappropriate, actions, such as outbursts of swearing.
In some rare cases, complex stereotypies and tics can develop from the use of certain drugs.
The specific treatment plan used for an individual depends on the type of dyskinesia and the severity or extent of symptoms.
If reducing or stopping the use of dyskinesia-causing medications do not stop symptoms, there are few other courses of treatment available.
Choosing an appropriate medication can also be challenging, given that many medications that help control muscle spasms are also known to cause dyskinesia.
Aside from medications, injections of botulinum toxin or Botox may help reduce or limit involuntary movements, especially those affecting the face.
Deep brain stimulation or DBS is a procedure where electrodes are placed in the brain to correct movement and control posture. DBS is considered most effective in people with cases of genetic or idiopathic dyskinesia, the latter being where there is no known cause.
Behavioral treatment studies have suggested that certain movements and stereotypies may be early diagnostic markers of autism in infants.