Tics & Tourette Syndrome
Tourette Syndrome (TS) is a neurological disorder characterized by multiple repeated tics. Tics are abrupt, purposeless, and involuntary movements or vocal sounds. Some are mild and barely noticeable, while others can be severe and disruptive.
TS is one type of tic disorder. Others include Chronic Tic Disorder (Motor or Vocal Type) and Provisional Tic Disorder. The three Tic Disorders are distinguished by the types of tics present (motor, vocal/ phonic, or both) and by the length of time that the tics have been present.
Individuals with Tourette Syndrome (TS) have had at least two motor tics and at least one vocal/ phonic tic in some combination over the course of more than a year. By contrast, individuals with Chronic Tic Disorder have either motor tics or vocal tics that have been present for more than a year. Individuals with Provisional Tic Disorder have tics that have been present for less than a year.
TS and Tic Disorders are likely to be caused by complex interactions between genetics and other factors, which may vary in different individuals. Studies are underway to find the genes and other factors underlying the development of these disorders.
Tic behaviors seen in TS change over time and vary in complexity. Symptoms are often defined in two categories:
- Motor tics or movements. Simple motor tics include: eye blinking, facial grimacing, jaw movements, head bobbing/jerking, shoulder shrugging, neck stretching, and arm jerking. Complex motor tics involve multiple muscle groups (e.g., hopping, twirling, jumping).
- Vocal/Phonic tics produce a sound. Simple vocal tics include: sniffing, throat clearing, grunting, hooting, and shouting. Complex vocal tics are words or phrases that may or may not be recognizable but occur out of context.