This publication is the third edition of A Physician's Guide to the Diagnosis and Treatment of Tourette Syndrome. Definitions of Tic Disorders Tics are involuntary, rapid, repetitive and stereotyped movements of individual muscle groups. They are more easily recognized than precisely defined. Common tics include eye blinking, nose puckering, grimacing and squinting.
Transient vocalizations are less common and include various throat sounds, humming or other noises.
Transient tics last only a few weeks or months and are usually not associated with specific behavioral or school problems. They are especially noticeable during times of heightened excitement or fatigue. As with all tic syndromes, boys are three to four times more often affected than girls. While transient tics by definition do not persist for more than a year, it is not uncommon for a child to have recurrent episodes of transient tics over the course of several years. Chronic tic disorders are differentiated from transient tic disorders not only by their duration over many years, but by their relatively unchanging character.