Tics

Tics are defined as sudden, habitual, nonrhythmic muscle contractions that produce involuntary movements and vocalizations (referred to as motor and vocal tics, respectively). They are generally categorized as either simple or complex. Simple tics involve rapid, meaningless, discrete movements or vocalizations. Common examples include eye blinking, sniffing, mouth twitching, shoulder jerking, and producing meaningless syllables or sounds (e.g., grunting or throat clearing). Complex tics have a more purposeful and sustained appearance and involve the sequential or simultaneous contraction of multiple muscle groups. Common examples include patterned touching or tapping, facial expressions, holding unusual postures, and saying particular words or phrases. Although swearing (coprolalia) is thought to be common due to media portrayals, it is relatively rare. Tics are the defining feature of a class of ...