Transient tic disorder is a neurological disorder characterized by sudden, repetitive, nonrhythmic motor movements or vocalizations called tics. Tics can include eye blinking, facial grimacing, shoulder shrugging, and throat clearing. Transient tic disorder usually begins in childhood between the ages of 2 and 15 years, with the average age of onset being around 5 or 6 years old. Tics often first appear during times of excitement, anxiety, fatigue, or stress. The exact cause of transient tic disorder is unknown, but it is thought to involve abnormalities in the parts of the brain that control motor function and impulse control.
What are the symptoms of transient tic disorder?
The main symptom of transient tic disorder is the presence of tics. Tics are classified into two categories:
- Motor tics involve physical movements such as eye blinking, nose twitching, head jerking, shoulder shrugging, arm thrusting, knee bending, or foot stamping.
- Vocal/phonic tics involve sounds such as sniffing, throat clearing, coughing, yelping, barking, grunting, or repeating words or phrases out of context.
Tics are often rapid, repetitive movements or vocalizations. They are usually sudden and intermittent. Tics tend to worsen with excitement, stress, anxiety, or fatigue. Many individuals with transient tic disorder report that they can voluntarily suppress their tics for varying lengths of time. Tics tend to improve with concentration on an engaging activity.
In transient tic disorder, tics come and go over time. They often occur in bouts lasting a few weeks or months, disappear for weeks or months, and then reappear. The tics change in location, frequency, type, complexity, and severity over time. Most children with transient tics experience periods where no tics are present.
What causes transient tic disorder?
The exact cause of transient tic disorder is unknown, but abnormalities in certain areas and circuits in the brain are believed to play a role. These include:
- Basal ganglia – involved in controlling voluntary motor movements
- Cortex – involved in executing voluntary movements
- Thalamus – relays information between subcortical structures and the cortex
- Dopaminergic system – uses the neurotransmitter dopamine to regulate motor function
Structural and functional imaging studies have found abnormalities in these regions in people with transient tic disorders compared to controls. However, the specific mechanisms are not fully understood.
In addition to brain abnormalities, genetics, infections, immunological factors, perinatal difficulties, and psychosocial stress may also contribute to the development of transient tics. However, much more research is needed to clarify causes.
Who gets transient tic disorder?
Transient tic disorder is more common in males than females, with males making up 70-90% of cases. The exact prevalence is unknown, but estimates range from 2-46% among school-age children. Prevalence decreases with age. Tic disorders overall are found worldwide, across cultures and ethnicities.
There are several risk factors that make someone more likely to develop transient tics, including:
- Being male
- Family history – genetic and hereditary factors
- Comorbid conditions like ADHD or OCD
- Birth complications
- Streptococcal infections
- Psychosocial stress
How is transient tic disorder diagnosed?
Transient tic disorder is diagnosed through a clinical evaluation by a doctor, often a child neurologist or psychiatrist. There are no blood tests or imaging that can definitively diagnose the condition. The evaluation involves:
- Medical history – assessing onset and duration of symptoms
- Family history – looking for tics or related disorders in family members
- Physical and neurological exam
- Discussion of tics – location, severity, triggers, ability to suppress
- Developmental and psychosocial assessment
- Screening for comorbidities like ADHD and OCD
The doctor will look for evidence of sudden, rapid, recurrent motor and/or vocal tics that occur in bouts and change in severity over time. Tics must begin before age 18 and occur for more than 4 weeks but less than 12 months for a diagnosis of transient tic disorder.
The condition must also not be attributable to any other medical condition or substance use. Doctors will rule out other causes of tics like medications, substance use, infections, brain injuries, or genetic disorders.
How is transient tic disorder treated?
Treatment for transient tic disorder focuses on managing symptoms rather than curing the condition. Many cases of transient tics in children resolve on their own without any treatment during the teenage years. Treatment may be recommended in severe cases or when tics interfere with daily life.
The main treatment approaches include:
- Education and support – Providing education about the nature of tics and offering reassurance. Stress management techniques may help reduce tic severity.
- Behavioral interventions – Habit reversal training and exposure with response prevention can help manage tics.
- Medications – Alpha-agonists like clonidine or guanfacine may be used to reduce tics.
Treatment focuses on managing any impairments related to tics rather than eliminating tics completely. Maintaining a normal life routine is encouraged. Treatment is customized to each patient’s needs and symptoms.
Education and Support
Providing education and support is an important component of treatment for both the child and family. It can help reduce stress and improve coping. Key educational points include:
- Tics are involuntary and not the child’s fault
- Tics naturally wax and wane
- Tics are common in childhood
- Many children will outgrow their tics by adulthood
- Trying to suppress tics constantly can be counterproductive
Support groups and school accommodations may help reduce tic-related impairments.
Behavioral Interventions
Two behavioral techniques that may help manage tics are:
- Habit reversal training – The child learns to be more aware of the urge to tic and then substitutes a less disruptive voluntary behavior instead. For example, squeezing a ball instead of vocalizing a tic.
- Exposure with response prevention – Repeatedly exposing the child voluntarily to the urge to tic without actually performing the tic. Over time this may reduce the frequency and intensity of the urge and tics.
These take time and practice but can be effective tic management skills.
Medications
Medications may be used in severe cases or when behavioral approaches are ineffective. The main medications used are alpha-agonists like:
- Clonidine – Reduces blood pressure but also reduces tics at higher doses. Side effects may include drowsiness, headaches, dizziness.
- Guanfacine – Similar effects to clonidine. Less sedation. Can cause dizziness, fatigue, irritability.
These medications help control tics through effects on norepinephrine activity in the brain. Their benefits must be weighed against potential side effects.
What is the prognosis for transient tic disorder?
The long-term outlook for children with transient tic disorder is generally very favorable. Tics tend to improve during the teenage years. Up to 85% of cases resolve completely by adulthood, often by age 18. The remaining 15% may see a reduction in tic frequency and severity but have persisting tics to some degree.
A minority of individuals with transient tic disorder go on to develop chronic tic disorders like Tourette syndrome if their symptoms last more than a year. Transient tic disorder has no direct effect on life expectancy.
Conclusion
In summary, transient tic disorder is a condition marked by temporary motor and vocal tics during childhood. Tics naturally wax and wane in severity. While the exact cause is unknown, abnormalities in the parts of the brain that control movement and behavior likely play a role. Transient tics often resolve by adulthood without treatment, but education, behavioral therapy, and medications can help manage bothersome symptoms. With support and accommodations, most children with transient tics can live normal lives.