Tics are very rapid purposeless twitches or jerks which are often preceded by an ill-defined urge to make the movement. Common motor tics include involuntary eye blinking, facial grimacing, and head shaking. Tics of the vocal system are common and include grunting, throat clearing, squeaking or other simple noises. More complex motor tics can be seen as can more complex vocalizations including in some cases involuntary profanity. Movements and vocalizations typically can be volitionally suppressed for short periods of time.
Tics usually begin in early childhood.
There is a spectrum of tic disorders ranging from simple tics which occur in childhood to full-blown GTS which includes a greater than one year history of motor tics and vocalizations often accompanied by behavioral disorders such as hyperactivity, attention deficit disorder, obsessive compulsive traits and behavior disorders. The diagnosis of GTS is made by a thorough analysis of history and the observation of tics on examination. Often, a videotape taken at home or school will help the physician see the tics better than in person in the office. Often one parent has or had tics during childhood and the tics may be so mild as to be unappreciated by non-medical observers. The brain appears structurally normal in GTS, and a chemical imbalance is hypothesized.