Stereotypic movement disorder is characterized by repetitive, but non-functional motor behavior which has lasted at least 4 weeks. Drugs may sometimes cause this condition, but in this case, symptoms last for a shorter period of time or stop when the offending medication is discontinued.

Causes, incidence, and risk factors

The causes of this disorder, when it occurs in the absence of other conditions, are unknown. The movements appear to increase with stress , frustration, and boredom. Stereotypic movement disorder is more common among boys. Stimulants (such as cocaine and amphetamines) can prompt a severe, but short (a few hours) period of stereotypical movement behavior, which may include repetitive and purposeless picking, hand wringing, head tics, or lip biting. With chronic stimulant abuse, these periods may last longer, but they usually resolve with cessation of the drug use. Tourette's syndrome and autism can also cause this disorder.

Signs and tests

A clinical exam is usually sufficient to diagnose this disorder. Tourette's syndrome, stimulant abuse, autism, and other potential causes should be considered and appropriate tests conducted.

Treatment

Treatment should be centered around the symptom, cause, and child's age. The environment should be changed for those children who are self-injurious to make sure they are safe. Behavioral techniques and psychotherapy have been the most successful treatment modalities. Some medications may also help reduce stereotyped behavior. Naltrexone has been used with some success in reducing stereotyped self-injurious behavior, but research on this is only preliminary.

Expectations (prognosis)

Expectations vary based on the cause. Stereotypy due to drugs usually goes away on its own after a few hours. Stereotypy due to head trauma may be permanent. All forms of stereotypy can be lessened with medications.

Complications

The motor stereotypies do not generally progress to worse disorders, such as seizures. However, they may be sufficiently severe to interfere with normal social functioning. Childhood stereotypic movement disorders may be indicate underlying Tourette's syndrome, autism, or other disorders. In teens and adults, stereotyped movements can also be symptoms of stimulant abuse, which should be investigated.

Calling your health care provider

Call your health care provider if your child exhibits repeated, odd movements that persist longer than a few hours.