USMLE® Step 1 style questions USMLE
A 10-year-old boy is brought to the clinic by his parents for evaluation of odd, repetitive behaviors. Over the past year, the patient has been blinking excessively, which his parents attributed to dry eyes and allergies. More recently, the patient has been frequently grimacing and clears his throat for no apparent reason. The parents are worried because the patient has been bullied in school for these behaviors. Past medical history is significant for seasonal allergies and an upper respiratory infection that developed several weeks ago. Throat cultures, antistreptolysin O titers, and anti-DNase B titers obtained during this episode were negative. The patient has been meeting all developmental milestones. He performs well at school, and language development is normal. Vitals and physical examination are unremarkable. Considering this patient’s most likely diagnosis, which of the following additional conditions is he at greatest risk for developing?
Tourette syndrome exam links
Content Reviewers:Rishi Desai, MD, MPH
Contributors:Tanner Marshall, MS
There are three major types of tic disorders listed in the DSM-5: Tourette syndrome, which is the most well-known; persistent motor or vocal tic disorder; and finally, provisional tic disorder.
Individuals with these disorders all suffer from tics, which are quick, nonrhythmic movements or vocalizations that occur over and over, and aren’t side effects of some other condition like Huntington’s disease or substance abuse.
For example, individuals might feel the urge to spontaneously and repeatedly clap their hands, make a facial grimace, grunt, or even perform hidden movements like moving the tongue around inside the mouth.
Although these actions and gestures might be appropriate in some situations, the fact that they are repeated even in inappropriate situations is why they are considered abnormal.
In addition to having a tic, three additional criteria are used to help differentiate between the three types of tic disorders.
Criteria A is the number of motor or vocal tics, criteria B is the duration of the tic disorder, and criteria C is the age of the person when they started having tics.
For a diagnosis of Tourette syndrome (also called Tourette’s), an individual must have multiple motor tics and at least one vocal tic; however, these do not have to happen at the same time.
The important thing here is that both motor and verbal tics are present.
The frequency of individual tics might change over time, but they need to persist for at least one year.
Finally, the tics must have started before the age of 18—in fact, they most often appear between the ages of 4 and 6.
Of the three types of tic disorders, Tourette’s is considered to be the most severe.
For a diagnosis of persistent motor or vocal tic disorder, also called chronic tic disorder, an individual must have either a single or multiple motor tics or vocal tics—but not both.
As with Tourette’s, the tics have to persist for at least a year and must have started before the age of 18.
Finally, for a diagnosis of provisional tic disorder, an individual must have a single or multiple motor and/or verbal tics, but they must be present for less than 1 year since their onset, and they must have appeared before the age of 18.
Tics can be simple or complex.
Simple tics are relatively short in duration, lasting milliseconds, and can include subtle behaviors like eye blinks, which are classed as motor tics, or throat clearing, which is considered a verbal tic.
Tourette syndrome is a neurodevelopmental disorder characterized by repetitive, involuntary movements and vocalizations called tics. The tics can be simple, such as eye blinking or throat clearing, or complex, such as jumping or shaking one's head while shrugging the shoulders.
There is no cure for Tourette syndrome, but treatment can help manage symptoms. Medications such as antipsychotics can help reduce tics. Cognitive-behavioral therapy can also be effective in managing tics and associated symptoms.