A tic is an involuntary movement or spoken sound.
It is repetitive and stereotyped. Tics come and go over time.
They vary in type, frequency, and severity.
Tics are classified as either simple or complex.
Simple motor tics are sudden, brief and repetitive.
A simple tic also affects a limited number of muscle groups.
Some of the more common simple tics include eye blinking and
facial grimacing. Shoulder shrugging and head or shoulder
jerking are also common. Simple vocal tics might include
throat clearing, sniffling, or grunting sounds.
Complex tics are coordinated patterns of movements.
Unlike simple tics, they involve several muscle groups.
Complex motor tics might include facial grimacing combined
with a head twist and a shoulder shrug. Sometimes complex
tics may appear as if they are done on purpose. Some
examples are sniffing or touching objects, hopping, jumping,
or bending. The most dramatic tics include movements that
result in self-harm. An example is punching oneself in the face.
Complex vocal tics include words or phrases, instead of just sounds.
They may also include uttering swear words or repeating the words
or phrases of others. Some tics are preceded by an urge or
sensation in the affected muscle group. This is called a
premonitory urge. People with TS say they have to complete
a tic in a certain way or a certain number of times. This helps to relieve the urge.
Tics are often worse with excitement or anxiety. They tend to get
better during calm, focused activities. Certain physical sensations can trigger
a tic or make it worse. For example, a tight collar may set off a neck tic
or hearing someone sniffle may set off a vocal tic. Tics do not go away
during sleep but are often significantly less active.
Tics may occur as a symptom of several disorders. These include
Tourette Syndrome, Autism and Transient Tic Disorder.
Adapted in part from "Tourette Syndrome Fact Sheet", NINDS. Publication date April 2005. NIH Publication No. 05-2163. Accessed on February 13, 2006 at
http://www.ninds.nih.gov/disorders/tourette/detail_tourette.htm - 56583231.
