M05.09.04 Tourette Syndrome

Tourette syndrome (TS) is a neurodevelopmental disorder characterized by the presence of multiple motor and vocal tics. It is essential to understand its features, genetic factors, associated conditions, and treatment options.

Key Characteristics

• Definition: TS is defined by the presence of multiple motor and vocal tics that occur many times per day or intermittently for more than one year.
• Gender Prevalence: Affects males more frequently than females, with a ratio of approximately 3:1.

Onset and Tic Types

• Mean Onset: Typically occurs around age 7; symptoms must appear before age 18.
• Tic Classification:
  • Simple Tics: Rapid, repetitive muscle contractions (e.g., blinking, head jerking).
  • Complex Tics: More ritualistic and purposeful movements (e.g., jumping, touching).

Genetic Factors

• Genetic Transmission: There is evidence of genetic transmission, with approximately 50% concordance in monozygotic (identical) twins.

Neurobiological Aspects

• Dopamine Levels: TS has been associated with increased levels of dopamine, a neurotransmitter involved in movement and behavior.

Associated Conditions

• Attention-Deficit/Hyperactivity Disorder (ADHD): Many individuals with TS also present with symptoms of ADHD.
• Obsessive-Compulsive Disorder (OCD): TS is often associated with OCD, another neurodevelopmental disorder.

Treatment Options

Points to Remember

• TS is characterized by both motor and vocal tics that must last for over a year.
• Onset typically occurs before the age of 18, with a peak around age 7.
• Genetic factors play a significant role, as evidenced by twin studies.
• The disorder is frequently comorbid with ADHD and OCD.
• Treatment options include haloperidol, pimozide, and clonidine.

References

1. Tourette Syndrome Association. (n.d.). Retrieved from Tourette Association
2. Scharf, J. M., & Moore, P. (2017). Genetics of Tourette syndrome: Recent advances. Current Neurology and Neuroscience Reports, 17(7), 52. DOI: 10.1007/s11910-017-0770-7
3. Wang, H., et al. (2015). The role of dopamine in Tourette syndrome: A review. Neuroscience & Biobehavioral Reviews, 56, 167-177. DOI: 10.1016/j.neubiorev.2015.07.014