Tourette syndrome is a complex neurological disorder that is characterized by repetitive, sudden, uncontrolled (involuntary) movements and sounds (vocalizations) called tics. Tourette syndrome is named for Georges Gilles de la Tourette, a French physician and neurologist, who first described this disorder in 1885. A variety of genetic and environmental factors likely play a role in causing Tourette syndrome. A small number of people with Tourette syndrome have been found to have mutations involving the SLITRK1 gene. The syndrome is believed to be linked to problems in certain areas of the brain, and the chemical substances (dopamine, serotonin, and norepinephrine) that help nerve cells talk to one another.
It is estimated that about 1% of the population has Tourette syndrome. Many people with very mild tics may not be aware of them and never seek medical help. Tourette syndrome is four times as likely to occur in boys as in girls. Although Tourette syndrome can be a chronic condition with symptoms lasting a lifetime, most people with the condition experience their worst symptoms in their early teens, with improvement occurring in the late teens and continuing into adulthood.
Tics — sudden, brief, intermittent movements or sounds — are the characteristic sign of Tourette syndrome. They can range from mild to severe. Severe symptoms might significantly interfere with communication, daily functioning and quality of life. The early symptoms of Tourette syndrome are almost always noticed first in childhood, with the average onset between the ages of 3 and 9 years.
Tics are classified as:
- Simple tics. These sudden, brief and repetitive tics involve a limited number of muscle groups.
- Complex tics. These distinct, coordinated patterns of movements involve several muscle groups.
Tics also can involve movement (motor tics) or sounds (vocal tics). Motor tics usually begin before vocal tics do. But the spectrum of tics that people experience is diverse.
Example of simple tics
- Eye blinking and other eye movements
- Facial grimacing
- Shoulder shrugging, and head or shoulder jerking
- Simple vocalizations might include repetitive throat-clearing, sniffing/snorting, grunting, or barking sounds
Example of complex tics
- Facial grimacing combined with a head twist and a shoulder shrug
- Sniffing or touching objects
Complex vocal tics include words or phrases.
Perhaps the most dramatic and disabling tics include motor movements that result in self-harm such as punching oneself in the face or vocal tics including coprolalia (uttering swear words) or echolalia (repeating the words or phrases of others). Some tics are preceded by an urge or sensation in the affected muscle group, commonly called a premonitory urge. Some individuals with Tourette syndrome will describe a need to complete a tic in a certain way or a certain number of times in order to relieve the urge or decrease the sensation
In addition, tics can:
- Vary in type, frequency and severity
- Worsen if you're ill, stressed, anxious, tired or excited
- Occur during sleep
- Change over time
- Worsen in the early teenage years and improve during the transition into adulthood
Although the cause of Tourette syndrome is unknown, current research points to abnormalities in certain brain regions (including the basal ganglia, frontal lobes, and cortex), the circuits that interconnect these regions, and the neurotransmitters (dopamine, serotonin, and norepinephrine) responsible for communication among nerve cells. Given the often complex presentation of Tourette syndrome, the cause of the disorder is likely to be equally complex.
In 2005, scientists discovered the first gene mutation that may cause some cases of Tourette syndrome. This gene, named SLITRK1, is normally involved with the growth of nerve cells and how they connect with other neurons. The mutated gene is located in regions of the brain (basal ganglia, cortex, and frontal lobes) previously identified as being associated with Tourette syndrome.
Non-genetic, environmental, post-infectious, or psychosocial factors—while not causing Tourette's—can influence its severity. Autoimmune processes may affect tic onset and exacerbation in some cases. In 1998, a team at the US National Institute of Mental Health proposed a hypothesis based on observation of 50 children that both obsessive–compulsive disorder (OCD) and tic disorders may arise in a subset of children as a result of a poststreptococcal autoimmune process. Children who meet five diagnostic criteria are classified, according to the hypothesis, as having Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections (PANDAS). This contentious hypothesis is the focus of clinical and laboratory research, but remains unproven.
Some forms of OCD may be genetically linked to Tourette's. A subset of OCD is thought to be etiologically related to Tourette's and may be a different expression of the same factors that are important for the expression of tics. The genetic relationship of ADHD to Tourette syndrome, however, has not been fully established.
Tourette syndrome cannot be prevented but understanding the risks
Risk factors for Tourette syndrome include:
- Family history. Having a family history of Tourette syndrome or other tic disorders might increase the risk of developing Tourette syndrome.
- Sex. Males are about three to four times more likely than females to develop Tourette syndrome.
There's no specific test that can diagnose Tourette syndrome. The diagnosis is based on the history of your signs and symptoms.
The criteria used to diagnose Tourette syndrome include:
- Both motor tics and vocal tics are present, although not necessarily at the same time
- Tics occur several times a day, nearly every day or intermittently, for more than a year
- Tics begin before age 18
- Tics aren't caused by medications, other substances or another medical condition
A diagnosis of Tourette syndrome might be overlooked because the signs can mimic other conditions. Eye blinking might be initially associated with vision problems, or sniffling attributed to allergies.
Both motor and vocal tics can be caused by conditions other than Tourette syndrome. To rule out other causes of tics, your doctor might recommend:
- Blood tests
- Imaging studies such as MRI
People with Tourette syndrome often lead healthy, active lives. However, Tourette syndrome frequently involves behavioral and social challenges that can harm your self-image. The overall prognosis is positive, but a minority of children with Tourette syndrome have severe symptoms that persist into adulthood. People with Tourette syndrome often lead healthy, active lives. However, Tourette syndrome frequently involves behavioral and social challenges that can harm your self-image.
Conditions often associated with Tourette syndrome include:
- Attention-deficit/hyperactivity disorder (ADHD)
- Obsessive-compulsive disorder (OCD)
- Autism spectrum disorder
- Learning disabilities
- Sleep disorders
- Anxiety disorders
- Pain related to tics, especially headache
- Anger-management problems
There's no cure for Tourette syndrome. Treatment is aimed at controlling tics that interfere with everyday activities and functioning. When tics aren't severe, treatment might not be necessary.
Medications to help control tics or reduce symptoms of related conditions include:
- Medications that block or lessen dopamine. Fluphenazine, haloperidol (Haldol) and pimozide (Orap) can help control tics. Possible side effects include weight gain and involuntary repetitive movements. Tetrabenazine (Xenazine) might be recommended, although it may cause severe depression.
- Botulinum (Botox) injections. An injection into the affected muscle might help relieve simple vocal tic.
- ADHD medications. Stimulants such as methylphenidate (Concerta, Ritalin, others) and medications containing dextroamphetamine (Adderall XR, Dexedrine, others) can help increase attention and concentration. However, for some people with Tourette syndrome, medications for ADHD can exacerbate tics.
- Central adrenergic inhibitors. Medications such as clonidine (Catapres) and guanfacine (Tenex) — typically prescribed for high blood pressure — might help control behavioral symptoms such as impulse control problems and rage attacks. Side effects may include sleepiness.
- Antidepressants. Fluoxetine (Prozac, Sarafem, others) might help control symptoms of sadness, anxiety and OCD.
- Antiseizure medications. Recent studies suggest that some people with Tourette syndrome respond to topiramate (Topamax), which is used to treat epilepsy.
- Behavior therapy. Cognitive Behavioral Interventions for Tics, including habit-reversal training, can help you monitor tics, identify premonitory urges and learn to voluntarily move in a way that's incompatible with the tic.
- Psychotherapy. In addition to helping you cope with Tourette syndrome, psychotherapy can help with accompanying problems, such as ADHD, obsessions, depression or anxiety.
- DBS (Deep Brain Stimulation). For severe tics that don't respond to other treatment, DBS might help. DBS involves implanting a battery-operated medical device in the brain to deliver electrical stimulation to targeted areas that control movement.