tourette's%20syndrome%20-and-%20other%20tic%20disorders
TOURETTE'S SYNDROME & OTHER TIC DISORDERS
Tics are sudden, rapid, non-rhytmic, repetitive, motor movements or vocalizations. The mean age of onset is approximately 5 years old.
Tourette's syndrome is the most common form of tic disorder.
There is a strong genetic component showing a 10- to 100-fold increase in the rates of tics and Tourette's syndrome among first-degree relatives of Tourette's syndrome patients.
Simple motor tics are restricted to a single or a few muscle groups and last less than a fraction of a second.
Complex motor tics involve larger muscle groups, usually last longer and appear purposeful and goal-directed.

Tourette's%20syndrome%20-and-%20other%20tic%20disorders Signs and Symptoms

Definition

Tics

  • Sudden, rapid, non-rhythmic, repetitive, motor movements or vocalizations
  • Mean age of onset is approximately 5 years with peak severity occurring between 10-12 years of age and declining in many children during adolescence
  • There is a strong genetic component showing a 10- to 100- fold increase in the rates of tics & Tourette  syndrome (TS) among 1st-degree relatives of Tourette syndrome patients

Etiology

Primary Causes of Tic Disorders

Inherited Tic Disorders

  • Tourette syndrome (TS)
  • Huntington’s disease
  • Primary dystonia
  • Neuroacanthosis

Sporadic Tics

  • Transient motor or phonic tics (<1 year duration)
  • Chronic motor or phonic tics (>1 year duration)
  • Adult-onset (recurrent tics)
  • Tourette syndrome

Secondary Causes of Tic Disorders

Primary Neurologic Disorders

  • Head trauma
  • Stroke
  • Encephalitis
  • Carbon monoxide poisoning
  • Neurosyphilis
  • Sydenham’s chorea
  • Hypoglycemia
  • Down syndrome
  • Tuberous sclerosis
  • Fragile X syndrome
  • Klinefelter’s syndrome
  • Chromosomal disorders
  • XYY karyotype
  • Duchenne’s disease
  • Hallervorden-Spatz disease
  • Creutzfeldt-Jakob disease

Primary Neuropsychiatric Disorders

  • Mental retardation
  • Schizophrenia
  • Asperger’s syndrome/autism

Drugs Which May Induce or Worsen Tics

  • Stimulants (eg Methylphenidate, Amphetamines, Pemoline)
  • Cocaine
  • Antipsychotics
  • Antidepressants
  • Anticonvulsants
  • Antihistamines
  • Lithium
  • Opioids & opioid withdrawal
  • Levodopa

Other movement disorders that need to be ruled out:

  • Eg myoclonic movements, torsion dystonia, chorea, stereotypies
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Dr. Richard Shek-Kwan Chang, 11 Oct 2018
A 38-year-old right-handed man had had epilepsy since 2 months of age. There was no relevant family history. Perinatal history was unremarkable. No other risk factors such as central nervous system infection or cerebral trauma were identified. Developmental history did not show major delay. His epilepsy was uncontrolled despite trying valproate, carbamazepine, clobazam, levetiracetam, oxcarbamazepine and perampanel.