Tic Disorders are brief, rapid, usually repetitive movements and sounds. Tics can affect any part of the body. Depending on distribution, they are defined as simple (affecting one group of muscles) or complex (affecting multiple muscle groups). Generally tics are irresistible, but can be suppressed for variable length of time. Vocal tics can be noises, throat clearing, or utterances of whole words or even sentences. The combination of complex motor tics and vocalizations is Tourette's syndrome (TS).
Tics usually start in childhood and either plateau or subside by young adulthood. However, some patients continue to have symptoms for the rest of life. Tics can exacerbate after a relatively quiescent period. Tics are a common disorder, with up to 4-5% of school age children affected. The cause of tics is unknown. However, there is a familial predisposition. Tics can be associated with behavioral disorders (ADHD) and obsessive-compulsive traits. Treatment of tics depends on the degree of movement-related disability. Not all patients require therapy. Effective medications include antipsychotics (haloperidol, primozide) and clonidine. Botulinum toxin injections can also be effective for simple motor tics. Botulinum toxin is derived from a bacterium which produces a protien that blocks the nerve from releasing acetylcholine. As a result, muscles relax and spasms diminish.