The cause of this disorder, when it occurs in the absence of other conditions, is unknown. The repetitive movements appear to increase with stress, frustration, and boredom. Stereotypic movement disorder is more common among boys than girls.

Stimulants such as cocaine and amphetamines can prompt a severe, but short period of stereotypic movement behavior. The behavior 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 may also cause this disorder.

• Rocking
• Head-banging
• Self-biting
• Nail-biting
• Hitting own body
• Handshaking or waving
• Mouthing of objects

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 should be centered around the symptoms, the cause, and the 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 methods.

Expectations vary based on the cause. Stereotypy (repetitive movements) 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.

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 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.

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