Tic disorders

A tic is a sudden, recurrent, involuntary, rapid motor movement or vocalization often exacerbated by stress and diminished during sleep. Common motor tics are eye-blinking, shoulder-shrugging, facial gestures, jumping or stamping. Common vocal tics are coughing, sniffing, snorting, throat-clearing, coprophasia (using "dirty" or obscene words), palilalia (repeating words or sounds) or echolalia (repeating the last-heard sounds of another person).