A tic is an unusual movement or sound that a person has little or no control over. It may include eye blinking, coughing, throat clearing, sniffing, facial movements, head movements, or limb movements, or making unusual sounds.
According to the Tourette Association of America, 1 in every 160 children in the United States may have Tourette's syndrome. It is thought to affect 200,000 Americans, and it affects males more than females.
The condition has been linked to damage or abnormalities in the basal ganglia of the brain.
Here are some key points about Tourette's syndrome. More detail is in the main article.
- A person with Tourette's syndrome will have physical and vocal tics lasting more than a year.
- It is a neurological disorder with symptoms that are made worse by stress.
- Treatment includes medication and behavioral therapy.
- Tourette's does not have serious complications, but it may be accompanied by other conditions, such as ADHD, and these can cause learning difficulties.
What is it?
Symptoms of Tourette's include frequent blinking, shaking the head, or clearing the throat.
Tourette's is one of a range of tic disorders that can involve transient or chronic tics. The tic can emerge at any age, but it most commonly appears between the ages of 6 and 18 years.
During adolescence and early adulthood, the tics will normally become less severe, but In 10 to 15 percent of cases, Tourette's can become worse as the person moves into adulthood.
For most people, the frequency and intensity of both minor and major tics tend to fluctuate. Tics may become more frequent and more intense when a person is facing physical, emotional, or mental stress.
Most people with Tourette's have normal intelligence and life expectancy.
The hallmark sign of Tourette's syndrome is a tic. This can range from barely noticeable to severe enough to make daily life challenging.
A facial tic, such as eye blinking, may be the first sign, but each person is different.
A tic may be:
- Physical: Motor movements include blinking or jerking the head or another part of the body.
- Phonic: The person may utter sounds, such as grunts or squeaks, and words or phrases.
There are two main classifications:
- Simple tic: This may involve moving just one muscle, or uttering a single sound. Movements are sudden, short lived, and often repetitive.
- Complex tic: The physical movements are more complex, and the phonic tics may include long phrases. Complex tics involve several muscle groups.
People with Tourette's have a combination of phonic and physical tics, which may be simple or complex.
Examples of simple physical tics may include:
- eye blinking
- eye darting
- grinding the teeth
- head jerking
- neck twisting
- nose twitching
- rolling the eyes
- rotating the shoulders
- shoulder shrugging
- sticking the tongue out
Examples of simple phonic tics may include:
- barking sounds
- clearing the throat
- yelling and screaming
Examples of complex physical tics may include:
- copropraxia, or making obscene gestures
- echopraxia, or miming the movements of other people
- head shaking
- hitting things
- jumping or hopping
- kicking things
- smelling objects
- touching oneself or others
Examples of complex phonic tics include:
- varying one's voice intonation
- echolalia, or repeating what other people say
- paliphrasia, or saying the same phrase over and over again
- coprolalia, which means uttering or shouting obscene words or phrases
Most people will experience unusual or uncomfortable sensations before the onset of a tic.
Types of advanced warning include:
- a burning feeling in the eyes that is only alleviated by blinking
- increasing tension in the muscles that can only be alleviated by stretching or twitching
- a dry throat that is only alleviated by grunting or clearing the throat
- itching in a limb or joint, where the only relief is achieved by twisting it
Situations that may cause tics to worsen include:
- anxiety or stress
- fatigue, or tiredness
- illness, especially a streptococcal infection
- a recent head injury
Medical News Today (MNT) asked the Tourette Association of America's Medical Advisory Board what advice they would give to parents who think their child may have Tourette's.
They told us:
"Tourette Syndrome is characterized by motor and vocal tics longer than 12 months. If this is the case, then start with a visit to the child's primary care physician for an evaluation. Talk to him or her to see if the tics are causing pain or discomfort, bothering him or her, or affecting schoolwork or desired activities.
The Association provide resources and support for people with Tourette's and for patents of children with the condition, including tools for parents and educators and information on how to find advocacy and support groups.
Causes and risk factors
The exact cause of Tourette's syndrome is unknown, but it appears to stem from a problem in the basal ganglia, the part of the brain that is responsible for involuntary movements, emotion, and learning.
Experts believe that abnormalities in the basal ganglia may cause an imbalance in levels of brain neurotransmitters, which transfer messages from one cell to another. Abnormal neurotransmitter levels may disrupt normal brain function, resulting in tics.
Tourette's syndrome is believed to have a genetic link and to be hereditary. A person who has a close family member with a tic is more likely to have one, too.
It also appears to be more common in infants who are born preterm.
Another theory is that a childhood illness may trigger tics. Infection with group A streptococcal bacteria has been linked with symptoms of Tourette's. It may be that the bacteria cause the immune system to produce antibodies that interact with brain tissue, and this brings about changes in the brain.
This could have implications for treatment, but more research is necessary.
There is no current test for Tourette's, so diagnosis depends on the signs and symptoms and medical and family history.
According to the Diagnostic and Statistical Manual of Mental Disorders Fifth edition (DSM-5), published by the American Psychiatric Association (APA), the following criteria must be present for a diagnosis of Tourette's:
- The person has two or more motor tics, for example, blinking or shrugging the shoulders and at least one vocal tic (for example, humming, clearing the throat, or yelling out a word or phrase), although they might not always happen at the same time.
- The person has had tics for at least a year. The tics can occur many times a day (usually in bouts) nearly every day, or off and on.
- The person has tics that began before the age of 18 years.
- The person has symptoms that are not due to taking medicine or other drugs or due to having another medical condition (for example, seizures, Huntington disease, or postviral encephalitis).
Other conditions that could produce similar symptoms include:
- allergies, if there is coughing and sniffing
- dystonia, a neurological condition that includes involuntary movements and prolonged muscle contraction, leading to twisting body motions, abnormal posture, and tremor
- restless leg syndrome, if movements affect the legs
- problems with vision, if the patient blinks a lot
Blood tests, a skin test, eye tests, and imaging tests can help rule out these and other medical conditions.
Treatment normally involves medication and non-pharmacological treatments. In rare cases, surgery may be an option.
Medication may include antihypertensives, muscle relaxants, or neuroleptics.
Antihypertensives are normally used to control high blood pressure, or hypertension, but they may help patients with mild to moderate symptoms of Tourette's, possibly by regulating neurotransmitter levels. One example is Clonidine. Side effects include diarrhea or constipation, dry mouth, headaches, dizziness, and fatigue.
Muscle relaxants help control physical tics by treating spasticity, when muscles become too stiff. Examples include baclofen and clonazepam. Side effects include drowsiness and dizziness. Patients taking muscle relaxants should not consume alcohol, and they may not be able to drive or use heavy machinery.
Neuroleptics block the effects of dopamine in the brain. They may be taken orally or by injection. They can treat moderate to severe symptoms. Some slow-release neuroleptics are injected only once every 2 to 6 weeks.
Adverse effects may include drowsiness, blurred vision, dry mouth, low libido, shaking, spasms, twitches, and weight gain. Some neuroleptics have more adverse effects than others.
If side effects are becoming a problem, the patients should tell their doctor. There may be other neuroleptics they could take.
Behavioral therapy is commonly used to help people with Tourette's. It can help change the patient's behavior patterns.
Studies have found that comprehensive behavioral intervention for tics (CBIT), a kind of cognitive behavioral therapy (CBT) may help children and adults with Tourette's syndrome. Therapy aims to treat symptoms by reversing habits.
Habit reversal is based on the idea that:
- patients are unaware of their tics
- the purpose of tics is to alleviate uncomfortable sensations before they occur
The therapist helps the patient monitor the pattern and frequency of their tics. Any sensations that are triggering the tics are also identified.
Once the patient is aware of the tic, they can develop an alternative and less noticeable way of relieving the uncomfortable sensations that are stirring. This is called a competing response.
For example, if an unpleasant sensation in the throat makes the person feel the need to grunt or clear their throat, they can learn to relieve the sensation by taking a series of deep breaths instead.
A study published in 2015 found that the kind of CBT used to reduce chronic tics in people with Tourette's syndrome can also change the way their brains work.
Another study published in 2015 found that a brain chemical known as GABA may help treat tics in people with Tourette's syndrome.
Habit reversal therapy often includes relaxation therapy. Stress or anxiety may make tics more severe and more frequent. Deep breathing and visualization may help relieve anxiety, often resulting in fewer and less severe tics.
Are there any alternative therapies?
Acupuncture and hypnosis have been proposed as possible therapies. A number of dietary factors have been suggested, such as a higher intake of vitamin B or vitamin D, but these have not been supported by research.
The Tourette Association Medical Advisory Board told MNT:
"There is no evidence at present for the use of any alternative therapies for the treatment of Tourette. Simply put, these have not been studied yet for Tourette."
However, exercise and a healthful diet can help reduce stress and enhance a sense of wellbeing, which may help reduce the severity and frequency of tics.
Surgery is usually only considered for adult patients with severe symptoms who have not responded well to other treatments.
Limbic leucotomy: An electric current or pulse of radiation is used to burn away a small part of the limbic system, which is responsible for some emotions, behavior and memory. This may resolve the problem partially or fully.
Deep brain stimulation (DBS): Electrodes are implanted permanently into parts of the brain known to be linked to Tourette's. They are connected to small generators that are implanted inside the body. An electronic pulse passes from the generator to the electrodes, stimulating different parts of the brain. This may help control the symptoms of Tourette's.
The long-term effects of DBS have not yet been proven.
Activities that may help include engaging in competitive sports, playing an enjoyable computer game, or reading an interesting book. However, overexcitement can be a trigger for some people, so some activities can have the opposite effect.
Many people learn how to control the tics when at work or school, for example, but suppressing tics may increase tension, until the tic can be expressed.
Over time, the types, frequency, and severity of tics may change. Tics tend to be most severe during the teenage years, but they often improve during early adulthood.
Tourette syndrome does not affect a person's intelligence, but learning difficulties can result if the person also has ADHD, OCD, or ASD.
A child with or without these additional conditions may also experience bullying at school, and this can make schooling harder, both socially and academically.
Schools can help by educating students about the condition, so that they can better understand a classmate who happens to have Tourette's.
The basal ganglia are also involved in habit learning, so people with Tourette's may have problems with learning through habit. This may affect skills such as writing, reading, or arithmetic.
A child with Tourette syndrome may need additional educational help.