Chronic motor tic disorder
Key points
- Tics are repeated, uncontrollable bursts of activity or speech.
- Chronic motor or vocal tic disorder is more common than the better-known Tourette's Syndrome.
- These symptoms (or any combination of them present in an affected person) can be voluntarily suppressed for a relatively brief length of time.
- Diagnosis of a tic is generally made during physical examination.
Alternative names
Chronic vocal tic disorder; tic - chronic motor tic disorder
Definition
Tics are repeated, uncontrollable bursts of activity or speech. Chronic motor tic disorder is characterized by rapid, recurrent, uncontrollable movements OR by vocal outbursts (but not both).
To be diagnosed with the disorder:
- The person has had the tics nearly every day for more than a year
- The person hasn't had a tic-free period longer than three months
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 length 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)
Written and revised by
David Cohen, M.D.
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