Definition

Tourette syndrome (TS) is a chronic, neurological disorder that is a member of a larger group of primary tic disorders. It is characterized by motor and vocal tics. Both motor and vocal tics must be present, though not necessarily at the same time. Tics must be present for more than one year, and its onset must be prior to age 18. Tics are rapid, involuntary movements or sounds that occur repeatedly.

Causes

In most cases, TS is inherited through a gene (or genes). However, some expressions of the gene may be milder tic disorders or obsessive-compulsive [2] symptoms with no tics. Sometimes there are no symptoms.

Some people with TS have no known family history of TS, tics, or obsessive-compulsive symptoms. Researchers are studying whether other factors, such as birth-related issues and autoimmune problems, may contribute to TS as well.

TS is one of the conditions grouped under the category Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal (or PANDAS). Studies suggests that, in some children, PANDAS are associated with Group A streptococcal or strep throat [3].

Researchers are studying whether the risk of PANDAS can be decreased by rapid treatment or prevention of strep infections. Also, studies need to be done to find out if some children are at a higher risk because of their genetic make-up. Overall, strep infection is common. So, if PANDAS are caused by the infection, then it's likely to occur rarely.

Other than this possible connection, the cause of tics is unknown. However, studies show that several brain [4] chemicals, called neurotransmitters, are involved. Dopamine and serotonin are the most likely. In addition, stress [5] and tension often increase tics.

Risk Factors

Tell your doctor if you have any of these risk factors:

• Family history of TS, other tic disorders, or obsessive-compulsive disorder
• Sex: male (three to four times more likely to be affected)
• Strep infection (may be a risk in some children)

There are many secondary causes of tics including:

• Hereditary disorders
• Carbon monoxide poisoning [6]
• Traumatic brain [4] injury
• Cerebral infections
• Medications
• Illicit drugs

Symptoms

Symptoms range from mild to severe, but most cases are mild. They can occur suddenly, and the length of time they last can vary. Tics may temporarily decrease with concentration or distraction. During times of stress [5], they may occur more often.

Tics are divided into motor and vocal, and then subdivided into simple and complex. The following are common examples:

• Motor tics
  
  • Simple—eye blinking, facial grimacing, head jerking, arm or leg thrusting
  • Complex—jumping, smelling, touching things or other people, twirling around
• Vocal tics
  
  • Simple—throat clearing, coughing, sniffing, grunting, yelping, barking
  • Complex—saying words or phrases that do not make sense in a given situation, saying obscene or socially unacceptable words (called coprolalia)

Many people with TS also have one or more of the following problems:

• Obsessions
• Compulsions and ritualistic behaviors
• Attention deficit disorder with or without hyperactivity [7] (ADD or ADHD)
• Learning disabilities
• Difficulties with impulse control
• Sleep disorders

While tics may occur throughout life, older teens may find that symptoms improve. In less than 10%-40% of cases, people have remission from symptoms.

Diagnosis

The doctor will ask about your symptoms and medical [8] history, and perform a physical exam. TS is diagnosed by observing the symptoms and reviewing when they began and how they progressed. There are no blood or neurological tests to diagnose TS. Some doctors may order an MRI scan [9] , CT scan [10] , EEG [11], or blood tests to rule out other disorders.

Treatment

Most people with TS do not need medical [8] treatment.

If you have a tic that disrupts daily activities, there are treatments—the most common being medication. However, the side effects may reduce how well the medication works.

No single [12] treatment is helpful for all people with TS, and treatment may not completely eliminate symptoms.

Prevention

There is currently no known way to prevent TS.