Description

Tourette syndrome (TS) is a childhood-onset neurobehavioral disorder characterized by the presence of multiple motor and at least one phonic tic.

• Tics are sudden, brief, repetitive, stereotyped motor movements (motor tics), or sounds (phonic tics) produced by moving air through the nose, mouth, or throat.
• Patients can suppress their tics, but this often causes inner tension that eventually results in more forceful tics.
• System(s) affected: nervous

Epidemiology

Etiology and Pathophysiology

Recent neuroimaging and electrophysiology research have pointed to possible abnormalities in frontal cortical volume and its connectivity. This supports circuit dysfunction contributing to excess dopamine/glutamate signaling, which is thought to be significant contributor to tic generation, involving decreased inhibitory output from the basal ganglia, which results in an imbalance of inhibition and excitation in the motor cortex (2).

• Thought to result from a complex interaction between social, environmental, and multiple genetic abnormalities
• Controversial pediatric autoimmune neuropsychiatric disorder associated with streptococcal infection (PANDAS); TS/OCD cases linked to immunologic response to previous group A β-hemolytic Streptococcus (GABHS)

Risk Factors

• Risk of TS among relatives: 9.8–15%
• Low birth weight, maternal stress, nausea/vomiting in 1st trimester, maternal smoking (3)

Commonly Associated Conditions

• OCD (28–67%), ADHD (50–60%), conduct disorder, learning disabilities (23%)
• Depression/anxiety including phobias, panic attacks, and stuttering; increased risk of contemplating suicide (1)
• Impairments of visual perception, sleep disorders, restless leg syndrome, and migraine headaches
• Cardiometabolic disorders, especially obesity, circulatory system diseases, type 2 diabetes (50%) (4)