Tics are classified as either simple or complex.
Simple motor tics are sudden, brief, repetitive movements that involve a limited number of muscle groups. Some of the more common simple tics include eye blinking and other vision irregularities, facial grimacing, shoulder shrugging, and head or shoulder jerking.
Simple vocalizations might include repetitive throat-clearing, sniffing, or grunting sounds.
Complex tics are distinct, coordinated patterns of movements involving several muscle groups.
Complex motor tics might include facial grimacing combined with a head twist and a shoulder shrug. Other complex motor tics may actually appear purposeful, including sniffing or touching objects, hopping, jumping, bending, or twisting. Simple vocal tics may include throat-clearing, sniffing/snorting, grunting, or barking.
More complex vocal tics include words or phrases. Perhaps the most dramatic and disabling tics include motor movements that result in self-harm such as punching oneself in the face or vocal tics including coprolalia (uttering swear words) or echolalia (repeating the words or phrases of others).
Some tics are preceded by an urge or sensation in the affected muscle group, commonly called a premonitory urge. Some with TS will describe a need to complete a tic in a certain way or a certain number of times in order to relieve the urge or decrease the sensation.
Tics are often worse with excitement or anxiety and better during calm, focused activities.
Certain physical experiences can trigger or worsen tics, for example tight collars may trigger neck tics, or hearing another person sniff or throat-clear may trigger similar sounds.
Tics do not go away during sleep but are often significantly diminished.
What is the course of TS?
Tics come and go over time, varying in type, frequency, location, and severity. The first symptoms usually occur in the head and neck area and may progress to include muscles of the trunk and extremities.
Motor tics generally precede the development of vocal tics and simple tics often precede complex tics. Most patients experience peak tic severity before the mid-teen years with improvement for the majority of patients in the late teen years and early adulthood.
Approximately 10 percent of those affected have a progressive or disabling course that lasts into adulthood.
Can people with TS control their tics?
Although the symptoms of TS are involuntary, some people can sometimes suppress, camouflage, or otherwise manage their tics in an effort to minimize their impact on functioning. However, people with TS often report a substantial buildup in tension when suppressing their tics to the point where they feel that the tic must be expressed. Tics in response to an environmental trigger can appear to be voluntary or purposeful but are not.
Involuntary movements - Actions beyond one's control that sometimes can be suppressed, but only for very limited periods and then must be expressed
Sources: National Institue of Mental Health (NIMH)
National Institute for Neurological Disorders and Stroke (NINDS)
All information quoted from these sources is in the public domain