Tics are involuntary or semivoluntary, abrupt, brief, nonrhythmic, recurrent movements or sounds. Tourette syndrome (TS) is the most common cause of tics; however, several other disorders have been associated with tics and tic-like movements. Etiologies of secondary tic syndromes and disorders (STS) include hereditary, drug-induced (including tardive), toxins, traumatic, cerebrovascular, infectious, parainfectious, autoimmune, functional disorders, and others. Age at onset after 18 years, lack…
