Summary
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.
Epidemiology
- Sex: ♂ > ♀ [1]
- Age of onset: usually 4–6 years of age (tics are most severe between 10–12 years of age and then decline during adolescence) [2]
Epidemiological data refers to the US, unless otherwise specified.
Etiology
- Hypothesized to be a combination of environmental, social, psychological, and genetic factors
- Associated conditions
- ADHD and/or OCD (most common)
- Learning disabilities
- Sleep disorders
- Conduct disorder and oppositional defiant disorder
- Mood and anxiety disorders
Clinical features
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Tics: 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.
Simple | Complex | |
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Vocal tics |
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Motor tics |
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Diagnostics
Tourette syndrome is a clinical diagnosis based on all of the following:
- Multiple motor tics and at least 1 vocal tic with a variable anatomical location, frequency, number, complexity, type, or severity over time
- Onset before 18 years of age
- Lasting > 1 year
- Not explained by other medical conditions or substance use (e.g., cocaine) [3]
Differential diagnoses
- Other tic disorders [4]
-
Sporadic transient tic disorder: a subtype of tic disorder particularly common in children, which manifests with motor or vocal tics that occur over a period of less than one year before resolving.
- Motor and/or vocal tics
- Age of onset: < 18 years
- Symptoms occur for less than 1 year (resolve spontaneously)
- Not explained by any other medical conditions or substance abuse
- Do not meet the criteria for Tourette syndrome
-
Persistent motor tic disorder or persistent vocal tic disorder are subtypes of tic disorder particularly common in children, which manifests with motor or phonic tics only.
- Motor or vocal tics (not both)
- Age of onset: < 18 years
- Persist > 1 year
- Not explained by any other medical conditions or substance abuse
- Do not meet the criteria for Tourette syndrome
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Sporadic transient tic disorder: a subtype of tic disorder particularly common in children, which manifests with motor or vocal tics that occur over a period of less than one year before resolving.
-
Stereotypic movement disorder
- Stereotypic, uncontrolled, repetitive movements lasting ≥ 4 weeks
- More common in children, especially boys, with neurological disorders and developmental retardation
- Includes rocking movements, hair pulling, hair twisting, and self-destructive behavior (e.g., head banging, picking at skin, hitting oneself) [5][6]
- Tardive dyskinesia
- Huntington disease
The differential diagnoses listed here are not exhaustive.
Treatment
- Support: counseling and education (for both caregivers and patients)
-
Behavioral therapy
- Indicated for mild, nondisabling symptoms
- Involves habit reversal training or Comprehensive Behavioral Intervention for Tics (CBIT)
-
Medical therapy [7]
- Indicated for severe or refractive cases despite behavioral therapy
- Alpha-adrenergic agonists: guanfacine; (often first-line therapy), clonidine (very sedating)
- Typical neuroleptic drugs: pimozide, haloperidol, fluphenazine (FDA-approved but may cause tardive dyskinesia)
- 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) [8]
- Deep brain stimulation (DBS): an alternative therapy in therapy refractory cases with severe tics [9]
Treatment of associated conditions (i.e., ADHD or OCD) can improve symptoms.
Prognosis
- Symptoms improve during adolescence. [2]
- May resolve spontaneously by 18 years of age (50% of cases) [10]