Chronic motor tic disorder is a condition that involves brief, uncontrollable, spasm-like movements or vocal outbursts (otherwise called phonic tics), but not both. If both a physical tic and vocal outburst are present, the condition is known as Tourette syndrome.
Chronic motor tic disorder is more common than Tourette syndrome, but less common than transient tic disorder. This is a temporary and self-limited condition expressed by tics. Another type is dystonic tics, which appear as abrupt bursts of movements followed by a sustained contraction.
Chronic motor tic disorder begins before the age of 18, and typically resolves within four to six years. Treatment can help lessen its effect on school or work life.
Doctors aren’t entirely sure what causes motor tic disorder or why some children develop it earlier than others. Some think chronic motor tic disorder may be the result of physical or chemical abnormalities in the brain.
Neurotransmitters are chemicals that transmit signals throughout the brain. They may be misfiring or not communicating correctly. This causes the same “message” to be sent over and over again. The result is a physical tic.
Children with a family history of chronic tics or twitches are more likely to develop chronic motor tic disorder. Boys are more likely to have chronic motor tic disorder than girls.
People with chronic motor tic disorder may display the following symptoms:
- facial grimacing
- excessive blinking, twitching, jerking, or shrugging
- sudden, uncontrollable movements of the legs, arms, or body
- sounds such as throat clearing, grunts, or groans
Some people have strange bodily sensations before a tic occurs. They’re usually able to restrain their symptoms for short periods of time, but this takes effort. Giving in to a tic brings a sense of relief.
Tics may be made worse by:
- excitement or stimulation
- fatigue or sleep deprivation
- extreme temperatures
Tics are typically diagnosed during a regular doctor’s office appointment. Two of the following requirements must be met in order for you or your child to receive a chronic motor tic disorder diagnosis:
- The tics must occur almost every day for more than a year.
- The tics must be present without a tic-free period of longer than three months.
- The tics must have started before the age of 18.
No test can diagnose the condition.
The type of treatment you receive for chronic motor tic disorder will depend on the severity of the condition and how it affects your life.
Behavioral treatments can help a child learn to restrain a tic for a short period of time. According to a 2010 study published in the Journal of the American Medical Association, a treatment approach called Comprehensive Behavioral Intervention for Tics (CBIT) significantly improved symptoms in children. In CBIT, children with tics are trained to recognize the urge to tic, and to use a replacement or competing response instead of the tic.
Medication can help control or reduce tics. Dopamine depleters and blockers are frequently used to control tics. They include:
Side effects can be serious and include movement disorders and blunted thinking (e.g., sedation, confusion, or paranoia). Tetrabenazine, which is less likely to cause movement disorders as a side effect compared to other medications, is increasingly being used as initial treatment for tics. Other medications, such as clonidine and guanfacine, are also used for mild cases.
Other medical treatments
Injections of botulinum toxin (commonly known as “Botox” injections) can treat some dystonic tics. Some people find relief with electrode implantations in the brain.
Children who develop chronic motor tic disorder between ages 6 and 8 usually recover. Their symptoms typically stop without treatment in four to six years.
Children who develop the condition when they’re older and continue to experience symptoms in their 20s may not outgrow the tic disorder. In those cases, it may become a lifelong condition.