Central nervous system
Central nervous system

Chronic motor tic disorder

Definition:
A disorder characterized either by rapid, recurrent, uncontrollable movements or by vocal outbursts (but not both) that have been present nearly every day for more than a year without a period free of the problem longer than three months. These repeated uncontrollable bursts of activity or speech are called tics.

Alternative Names:
Chronic vocal tic disorder

Causes, incidence, and risk factors:

Chronic motor or vocal tic disorder is more common than the better-known Tourette's Syndrome. About 1 to 2% of the population is affected. This condition is rare, however, compared to the common short-lived childhood tic (transient tic disorder), which occurs and then stops without treatment within a year.

Tics appear to get worse during emotional stress and are absent during sleep. It is thought that all types of chronic tics are variants of Tourette's Syndrome and have an underlying genetic cause. The gene or genes involved have not been discovered yet.

Symptoms:
  • Vocalizations (grunts, throat clearing, abdominal or diaphragmatic contractions)
  • Facial grimacing
  • Excessive blinking
  • Rapid, recurrent movement of the arms, legs, or other areas

These symptoms (or any combination of them present in an affected person) can be voluntarily suppressed for a relatively brief lenght of time. A sensation of relief is experienced when these movements have been carried out. Tics can also be suggestible, may persist during all stages of sleep, and may exacerbate with stress, heat, excitement, and fatigue.

Signs and tests:
Diagnosis of a tic is generally made during physical examination. No tests are usually necessary.
Treatment:

Treatment of chronic motor or vocal tic disorder depends on its severity, the distress it causes to the patient, and the effects the tics have on school or job performance. Medication and psychotherapy are used only when there is substantial interference with ordinary activities.

Drugs used to treat tics (dopamine blockers, such as pimozide and risperidone) have a limited rate of success and a relatively high level of side effects.

Expectations (prognosis):
The prognosis for children who develop this disorder between the ages of 6 to 8 is good. Symptoms may last 4 to 6 years and then stop without treatment in early adolescence. When the disorder begins in older children and there is no remission or reduction of symptoms well into the 20s, a chronic, life-long disorder may be anticipated.
Complications:
There are usually no complications.
Calling your health care provider:
There is usually no need to see the health care provider for a tic unless it is severe or becomes disruptive to the child's life. If there is a question whether the movements are really a tic (as opposed to a seizure, for example), consult with your health care provider.

Review Date: 5/17/2002
Reviewed By: Alberto Espay, M.D., Department of Neurology, Toronto Western Hospital, University of Toronto, Toronto, Ontario, Canada. Review provided by VeriMed Healthcare Network.
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