Tics are sudden, rapid, recurrent, and non-rhythmic movements or vocalizations common in childhood. They are a type of hyperkinetic movement disorder characterized by excess unwanted movement. While the term “baby tics” is often used, tics most frequently begin in children between the ages of five and ten, often appearing in the preschool or early school years. Most children who experience tics have a mild, temporary presentation that resolves on its own.
Identifying Motor and Vocal Tics
Tics are categorized into two main groups: motor tics (physical movements) and vocal tics (sounds). They are also classified as simple or complex, depending on the number of muscle groups involved. Simple tics are brief, abrupt, and involve only a few muscle groups, making them the most common initial presentation.
Simple motor tics frequently affect the face, head, and shoulders:
- Rapid eye blinking
- Facial grimacing
- Head jerking
- Shoulder shrugging
Simple vocal tics are sounds produced by moving air through the nose, mouth, or throat. These often manifest as:
- Sniffing
- Throat clearing
- Grunting
- A sudden cough
A distinguishing characteristic of tics is their semi-voluntary nature; they are generally preceded by an uncomfortable sensation or urge. This “premonitory urge” builds up until the child performs the tic, which provides temporary relief. Children can often suppress a tic for a short time. However, suppression usually increases internal tension, resulting in a burst of tics later, such as when they arrive home from school.
Complex tics involve distinct, coordinated patterns of movement or meaningful sounds using several muscle groups. Complex motor tics might include jumping, touching objects, or bending and twisting the trunk. Complex vocal tics can involve repeating one’s own words or phrases, repeating the words of others, or, rarely, uttering socially inappropriate words.
Distinguishing Tics from Normal Childhood Movements
Parents often find it challenging to differentiate tics from other common childhood movements, such as habits or motor stereotypies. Tics are generally non-rhythmic and discrete, lacking a predictable beat or pattern. They also tend to “wax and wane,” changing in type, location, frequency, and severity over weeks or months.
Motor stereotypies, by contrast, are patterned, repetitive, and often rhythmic movements consistent over time. Common stereotypies usually begin at a younger age than tics and include:
- Body rocking
- Head nodding
- Hand flapping
- Finger wiggling
Stereotypies are often comforting or self-soothing and can be abruptly stopped with distraction.
The presence of a premonitory urge helps distinguish a tic from a stereotypy, though very young children may not be able to describe this sensation. Stereotypies are often not preceded by this uncomfortable feeling, and the child may be unaware they are performing the movement. Tics are involuntary but suppressible, whereas stereotypies are involuntary and non-suppressible but often disappear with focused concentration.
Transient vs. Chronic Tics and Contributing Factors
Tics are formally classified based on the types present and the duration of occurrence. The most common form is Provisional Tic Disorder, often called transient tics, which affects up to ten percent of children during their early school years. For this diagnosis, motor or vocal tics must be present for less than 12 consecutive months.
Tics persisting for one year or more are classified as Chronic Motor or Vocal Tic Disorder. This diagnosis applies when a child has either motor tics or vocal tics, but not both, for over a year. When a child has both multiple motor tics and at least one vocal tic for more than a year, the condition is classified as Tourette syndrome.
While the underlying cause involves complex neurobiological and genetic factors, several elements can influence tic presentation. Tics frequently worsen during periods of heightened emotional arousal, whether positive or negative. Common triggers that increase frequency and severity include stress, anxiety, excitement, and fatigue.
Since tics can be suppressed, they often become more noticeable when a child is relaxed, such as while watching television or during quiet periods at home. Conversely, they may temporarily decrease during periods of intense concentration or focused physical activity. The symptoms often follow a waxing and waning course, meaning they can be severe one month and almost disappear the next, regardless of intervention.
When to Consult a Pediatrician
While most tics are mild and resolve without intervention, specific circumstances warrant a professional evaluation. Parents should consult a pediatrician if the tics have lasted for a year or more, suggesting the possible presence of a chronic tic disorder. Consultation is also appropriate if the tics are severe, frequent, or suddenly begin to interfere with the child’s daily life.
Interference with daily activities includes tics that cause difficulty with reading due to frequent eye blinking, social isolation due to embarrassment, or problems concentrating in school. Pain or discomfort is another indicator, such as muscle soreness from aggressive head or shoulder jerking. Pediatricians can help rule out other potential causes, such as seizure disorders or movement disorders, and assess for co-occurring conditions.
Many children with chronic tics also experience conditions like attention-deficit/hyperactivity disorder (ADHD), anxiety, or obsessive-compulsive disorder (OCD). Treating these associated conditions is often as important as addressing the tics. Parents should document the tics’ frequency, type, and noticeable triggers before the appointment to assist the clinician in making an accurate assessment.