Chronic Motor Tic Disorder

What chronic motor tic disorder is

A tic is a sudden, rapid, repeated movement or sound that a person feels driven to make. Many people describe an uncomfortable feeling before a tic, like an itch or a need to sneeze, that is relieved once the tic happens. This is called a premonitory urge. Tics can be held back for a while, but the urge builds up.

Doctors classify tic disorders by which tics are present and for how long:

In all of them, tics start before age 18 and are not caused by a drug or another medical condition. The current psychiatric manual (DSM-5-TR) calls the condition persistent (chronic) motor or vocal tic disorder, with motor tics only.

Symptoms

Simple motor tics

These are brief movements involving one muscle group:

• eye blinking, eye rolling or squinting
• nose twitching or wrinkling
• mouth movements or grimacing
• head jerking or nodding
• shoulder shrugging
• arm or leg jerks, finger flexing, tensing the stomach

Complex motor tics

These are slower or more coordinated, and can look deliberate: touching objects or people, jumping, bending, twisting, smelling things, or copying other people's gestures.

How tics behave

• They wax and wane. Tics can be frequent for weeks, then quiet, and old tics are often replaced by new ones.
• They get worse with stress, excitement, tiredness and illness, and often when a child relaxes at home after school.
• They usually lessen during focused activity such as sports, music or a video game, and during sleep.
• Many children can suppress tics at school, then release them at home. This is why teachers may not notice them.

Causes and risk factors

Tic disorders are neurodevelopmental conditions. They involve the circuits linking the basal ganglia (deep brain structures that control movement) and the frontal lobes, with a role for the chemical messenger dopamine. They are not caused by poor parenting or by emotional problems, although stress can make tics worse.

Risk factors include:

• Family history: tic disorders, Tourette syndrome and OCD run in families. Chronic motor tic disorder and Tourette syndrome are thought to be different points on the same genetic spectrum.
• Male sex.
• Pregnancy and birth factors such as smoking in pregnancy, low birth weight and premature birth have been linked in some studies.

Conditions that often occur alongside

Children with chronic tics more often have:

• attention deficit hyperactivity disorder (ADHD)
• obsessive-compulsive disorder or obsessive traits
• anxiety
• learning difficulties, sleep problems and anger outbursts

These often cause more day-to-day difficulty than the tics themselves, so doctors screen for them.

Diagnosis

There is no test for a tic disorder. A pediatrician, neurologist or psychiatrist makes the diagnosis by:

• asking when tics started, which ones have occurred and whether any were sounds (such as sniffing, throat clearing or grunting, which would point to Tourette syndrome)
• watching the tics, or reviewing videos taken at home
• asking about family history, medicines and other symptoms
• examining the nervous system to rule out other movement problems

Tests such as an EEG, brain MRI or blood tests are only needed when something is unusual: tics starting in adulthood, loss of skills, or movements that look more like seizures, dystonia (sustained twisting postures) or chorea (flowing, dance-like movements). Repetitive sniffing or throat clearing from allergies can be mistaken for tics, and the reverse.

Treatment

Many children need no treatment beyond explanation and reassurance. Treatment is offered when tics cause pain, embarrassment, bullying, or interfere with school, work or sleep.

Behavioral therapy

Comprehensive Behavioral Intervention for Tics (CBIT) is the first-line treatment recommended by the American Academy of Neurology. It is based on habit reversal training:

1. Awareness training: learning to notice the premonitory urge.
2. Competing response: doing a movement that makes the tic physically impossible, such as gently pressing the lips together or tensing the neck, until the urge passes.
3. Changing triggers: adjusting situations that make tics worse.

CBIT typically involves 8 to 10 sessions and reduces tic severity in a substantial share of children and adults. Exposure and response prevention is an alternative.

Medicines

When tics stay troublesome, a doctor may prescribe:

• Alpha-2 agonists (guanfacine, clonidine): often tried first, especially if ADHD is also present. Side effects include tiredness and low blood pressure.
• Antipsychotics (aripiprazole, risperidone and others): more effective for tics but with more side effects, such as weight gain and metabolic changes.
• Topiramate in some cases.
• Botulinum toxin injections for a single persistent tic, such as a forceful neck or eye tic.

Medicines reduce tics but rarely stop them completely.

Support at home and school

• Avoid pointing out or telling a child to stop a tic. This increases attention and stress.
• Inform teachers. Classroom accommodations can include breaks, extra time on tests and a quiet place to release tics.
• Treat ADHD, anxiety and sleep problems, which can lower overall tic levels.

Outlook

The outlook is good. Tics typically begin between ages 4 and 7, are most severe around ages 10 to 12, and decrease during the teenage years. Many people have few or no tics by early adulthood. A smaller group keeps mild tics lifelong. Tics that begin after age 18 are unusual and need a medical review for another cause.

Frequently asked questions

What is the difference between chronic motor tic disorder and Tourette syndrome?

Both involve tics lasting more than a year that begin before 18. Tourette syndrome requires multiple motor tics plus at least one vocal tic. Chronic motor tic disorder involves motor tics only, never sounds. It is generally milder and less often comes with other conditions, although ADHD and OCD can still occur.

Can chronic motor tic disorder go away?

Often, yes. Tics usually peak before the teenage years and then decline. Many young people have few or no noticeable tics by their late teens or twenties. Some keep mild tics into adulthood, and stress can bring them back temporarily.

Is it a mental illness?

It is classed as a neurodevelopmental disorder, alongside conditions such as ADHD. It reflects differences in brain circuits that control movement, not a psychological problem. It does not affect intelligence. Anxiety and stress do not cause it, but they can make tics more frequent.

Should I tell my child to stop the tic?

No. Tics are involuntary. Asking a child to stop increases stress and self-consciousness, which usually makes tics worse. If tics are a problem, behavioral therapy teaches a structured way to manage the urge, which works far better than willpower.

Can adults be diagnosed with chronic motor tic disorder?

Yes, if tics started before age 18 and have lasted more than a year. Many adults were never diagnosed as children. Tics that begin for the first time in adulthood are different and should be checked for other causes such as medicines, brain injury or functional movement disorders.