- Clinical science
Tourette syndrome is a severe neurological movement disorder characterized by tics, which are involuntary, repeated, intermittent movements or vocalizations. It is a genetic disorder that commonly presents in boys and is often associated with attention deficit hyperactivity disorder (ADHD) or obsessive-compulsive disorder (OCD). Diagnosis is based upon multiple motor tics and at least one vocal tic, lasting for longer than a year, and the exclusion of other suspected medical conditions. Treatment is symptomatic and includes behavioral therapy and dopamine antagonists. Approximately 50% of cases resolve by adulthood.
- Sex: ♂ > ♀
- Age of onset: usually 2–15 years of age
Epidemiological data refers to the US, unless otherwise specified.
- Hypothesized to be a combination of environmental, social, psychological, and genetic factors
- Autosomal dominant inheritance is possible (rare)
- Sudden and rapid involuntary, intermittent, nonrhythmic movements or vocalizations without any recognizable purpose
- Temporarily suppressible
- An urge or sensation preceding the tic is relieved by its onset.
|Vocal tics|| |
|Motor tics|| || |
Clinical diagnosis based on all of the following:
- Other Tic disorders
- Sporadic transient tic disorder (occurs in up to 25% of normal children)
- Persistent motor tic disorder or persistent vocal tic disorder
Stereotypic movement disorder
- Stereotypic, uncontrolled, repetitive movements lasting ≥ 4 weeks
- More common in children, especially boys, with neurological disorders and developmental retardation
- Inlcudes rocking movements, hair pulling, hair twisting, and self-destructive behavior (e.g., head banging, picking at skin, hitting oneself)
- Seizures (see )
The differential diagnoses listed here are not exhaustive.
- Support: Counseling and education (caregivers and patients)
- Indicated for mild, nondisabling symptoms
- Involves habit reversal training or Comprehensive Behavioral Intervention for Tics (CBIT)
- Indicated for severe or refractive cases despite behavioral therapy
- Alpha-adrenergic agonists: guanfacine; (often first-line therapy), clonidine (very sedating)
- Typical neuroleptic drugs: pimozide; or haloperidol (FDA-approved but may cause )
- Atypical neuroleptic drugs: risperidone (increasingly preferred because of fewer side effects)
- Dopamine depleting drugs: tetrabenazine (may be used as first-line therapy to avoid side effects of neuroleptic drugs i.e., dopamine blockade)
Treatment of associated conditions (i.e., ADHD or OCD) can improve symptoms!
- Symptoms peak during adolescence and improve during adulthood.
- May resolve spontaneously by 18 years of age (50% of cases)