Functional tics are dramatic, involuntary movements or sounds usually made in response to a trigger. While similar to other tic disorders, they have different causes and treatment options. Functional ...

Motor tics are spasmodic contractions of muscles, which typically involve the face and are habitual. Examples include squinting the eyes, grimacing, or even turning the head. Sometimes motor tics ...

How common are tics during childhood? Tics are so widespread that some experts say they are a normal part of growing up. About 20 percent of children will develop a tic—an involuntary movement such as ...