The Tic Disorder

Tourette Syndrome (TS), first described by Gilles de la Tourette, can be the most debilitating tic disorder, and is characterized by multiform, frequently changing motor and phonic tics. The prevailing diagnostic criteria include onset before the age of 21; recurrent, involuntary, rapid, purposeless motor movements affecting multiple muscle groups; one or more vocal tics; variations in the intensity of the symptoms over weeks to months (waxing and waning); and a duration of more than one year. …

…years, but also by their relatively unchanging character. While transient tics come and go - with sniffing replaced by forehead furrowing or finger snapping, chronic tics - such as contorting one side of the face or blinking - may persist unchanged for years. Chronic multiple tics suggest that an individual has several chronic motor tics. It is often not an easy task to draw the lines between transient tics, chronic tics, and chronic multiple tics.