Sammy, age 7, is referred to you by his pediatrician because of a 4-week history of frequent eye blinking. His parents say he blinks a lot when bored but very little when playing baseball. They recall that he also has intermittently sniffed and nodded his head over the last 12 months. Neither Sammy nor his friends seem to be bothered by the blinking. Except for the tics, Sammy’s physical and mental status exams are normal.
Since preschool, Sammy’s teachers have complained that his backpack and desk are always a mess. Sammy is well-meaning but forgetful in his chores at home. A paternal uncle has head-turning movements, counts his steps, and becomes distressed if books on his shelf are not in alphabetical order.
Tics, such as strong eye blinks or repetitive shoulder shrugs, can distress a child or his/her parents, but the conditions associated with tic disorders often are more problematic than the tic disorder itself. High rates of comorbid conditions are recognized in persons with Tourette syndrome, including:
- obsessive-compulsive disorder (OCD) in >80%1
- attention-deficit/hyperactivity disorder (ADHD) in ≤70%2
- anxiety disorders in 30%3
- rage, aggression, learning disabilities, and autism less commonly.
The strategy we recommend for managing tic disorders includes assessing tic severity, educating the family about the illness, determining whether a comorbid condition is present, and managing these conditions appropriately. Above all, we emphasize a risk-benefit analysis guided by the Hippocratic principle of “do no harm.”
Characteristics of tic disorders
You diagnose Sammy with Tourette syndrome because he meets DSM-IV-TR criteria of at least 2 motor tics and 1 vocal tic that have persisted for 1 year without more than a 3-month hiatus, with tic onset before age 18. Because tics may resemble other movement disorders, you rule out stereotypies, dystonia, chorea, ballism, and myoclonus (Table 1). You explain to his parents that Sammy’s condition is a heritable, neurobehavioral disorder that typically begins in childhood and is associated in families with OCD, ADHD, and autism spectrum disorders.
His parents ask about the difference between tics and other movements. You explain that eye-blinking tics—like other motor tics—appear as sudden, repetitive, stereotyped, nonrhythmic movements that involve discrete muscle groups. (View a video of a patient with tics.) Simple motor tics are focal movements involving 1 group of muscles, whereas complex tics are sequential patterns of movement that involve >1 muscle group or resemble purposeful movements (Table 2).
Table 1
Features of 5 movement disorders that may resemble tics
| Tics | Stereotypies | Dystonia | Chorea | Ballism | Myoclonus |
|---|---|---|---|---|---|
| Sudden, repetitive, stereotyped, nonrhythmic movements or sounds | Patterned, nonpurposeful movement | Cocontraction of agonist and antagonist muscles, causing an abnormal twisting posture | Continuous, flowing, nonrhythmic, nonpurposeful movement | Forceful, flinging, large amplitude choreic movement | Sudden, quick, shock-like movement |
| Usually start after age 3 | Usually start before age 3 and resolve by adolescence | More common in adults | — | — | — |
| Decrease when focused; increase when stressed, anxious, fatigued, or bored | Occur when the child is excited | Worsens during motor tasks | Worsens during motor tasks | Worsens during motor tasks | — |
| Comorbid conditions include OCD and ADHD | Common in children with mental retardation or autism | — | Can occur after streptococcal infection | Can occur after streptococcal infection | — |
| Preceded by a premonitory urge or sensation | Possibly preceded by an urge | Not preceded by an urge | Not preceded by an urge | Not preceded by an urge | Not preceded by an urge |
| Temporarily suppressible | Suppressible | Not suppressible | Partially suppressible; can incorporate into semi-purposeful movements | Partially suppressible | Not suppressible |
| ADHD: attention-deficit/hyperactivity disorder; OCD: obsessive-compulsive disorder | |||||
Table 2
Characteristics of simple and complex motor and vocal tics*
| Simple tics | Complex tics |
|---|---|
| Eye blinking or eye rolling Nose, mouth, tongue, or facial grimaces (nose twitch, nasal flaring, chewing lip, teeth grinding, sticking out tongue, mouth stretching, lip licking) Head jerks or movements (neck stretching, touching chin to shoulder) Shoulder jerks/movements (shoulder shrugging, jerking a shoulder) Arm or hand movements (flexing or extending arms or fingers) Coughing Throat clearing, grunting Sniffing, snorting, shouting Humming | Jumping Spinning Touching objects or people Throwing objects Repeating others’ action (echopraxia) Obscene gestures (copropraxia) Repeating one’s own words (palilalia) Repeating what someone else said (echolalia) Obscene, inappropriate words (coprolalia) |
| *Simple tics are focal movements involving 1 group of muscles; complex tics are sequential patterns of movement that involve >1 muscle group or resemble purposeful movements | |
Older children frequently describe a premonitory urge prior to the tic. Patients typically can suppress tics for a transient period of time, although during tic suppression they usually feel restless and anticipate performing their tic. The ultimate performance of the tic brings relief. Tic suppression also occurs during focused activity. Emotional stress, fatigue, illness, or boredom can exacerbate tics.