Tardive dyskinesia Health Article

Definition

Tardive dyskinesia is a neurological disorder consisting of abnormal, involuntary body movements caused by certain medicines. It is usually associated with long-term use of medicines for treating schizophreniaand other psychotic disorders.

Description

Tardive means "late" and dyskinesia means "abnormal movements." It refers to abnormal body movements that occur after a person has been taking a certain medicine for a long period of time. It sometimes starts after the medicine has been discontinued. In the early stages, the movements may be so subtle that neither the person nor the people around him or her notice them. For instance, the person may blink rapidly or lick their lips often. In later stages, the movements become noticeable and may affect the person's physical abilities.

Other types of tardive dyskinesia can occur. In tardive dystonia, there are abnormal contractions of the neck and shoulder muscles. In tardive akathisia, the person feels restless all the time.

Causes

It is not altogether certain what causes tardive dyskinesia. The medicines that cause it affect how nerve impulses are transmitted across gaps between nerve cells (synapses). They do this in part by blocking a chemical made by the body called dopamine. After a while, the nerves seem to become hypersensitive to dopamine. Stimulation by even a little bit of dopamine may cause the abnormal movements.

The medicines most commonly associated with tardive dyskinesia include:

• Antipsychotic medicines used to treat schizophrenia and other psychoses. These are also known as neuroleptic medicines.
• Levodopa or L-dopa, which is used to treat Parkinson's disease (although high doses of L-dopa may actually help control tardive dyskinesia).
• Antiemetic medicines used to control nausea and vomiting.
• Tricyclic antidepressants used to treat depression and other mood disorders.
• Other medicines that block dopamine.

Symptoms

Symptoms of tardive dyskinesia include:

• involuntary movements of the face, including frowning, blinking, smiling, lip licking, mouth puckering, biting or chewing, clenching the jaw, sticking out the tongue, or rolling the tongue around in the mouth
• involuntary movements of the hands, arms, feet, or legs, such as twitching the hands or tapping the feet
• trunk movements, such as rocking, twisting, or squirming
• grunting or trouble speaking because of involuntary movements of the diaphragm

Movements may be rapid or slow and complicated. They are usually irregular and do not follow a pattern.