Tics can be either simple or complex. Simple motor tics are of short duration (i.e., milli- seconds) and can include eye blinking, shoulder shrugging, and extension of the extrem- ities. Simple vocal tics include throat clearing, sniffing, and grunting often caused by contraction of the diaphragm or muscles of the oropharynx. Complex motor tics are of lon- ger duration (i.e., seconds) and often include a combination of simple tics such as simul- taneous head turning and shoulder shrugging. Complex tics can appear purposeful, such as a tic-like sexual or obscene gesture (copropmxiu) or a tic-like imitation of someone else’s movements (echopraxz'u). Similarly, complex vocal tics include repeating one’s own sounds or words (pulilalia), repeating the last—heard word or phrase (echolalia), or uttering socially unacceptable words, including Obscenities, or ethnic, racial, or religious slurs (coprolalia).
Importantly, coprolalia is an abrupt, sharp bark or grunt utterance and lacks the prosody of similar inappropriate speech observed in human interactions.
The presence of motor and/ or vocal tics varies across the four tic disorders (Criterion
A). For Tourette’s disorder, both motor and vocal tics must be present, whereas for per- sistent (chronic) motor or vocal tic disorder, only motor or only vocal tics are present. For provisional tic disorder, motor and / or vocal tics may be present. For other specified or un- specified tic disorders, the movement disorder symptoms are best characterized as tics but are atypical in presentation or age at onset, or have a known etiology.
The 1-year minimum duration criterion (Criterion B) assures that individuals diag— nosed with either Tourette’s disorder or persistent (chronic) motor or vocal tic disorder have had persistent symptoms. Tics wax and wane in severity, and some individuals may have tic-free periods of weeks to months; however, an individual who has had tic symp- toms of greater than 1 year’s duration since first tic onset would be considered to have per- sistent symptoms regardless of duration of tic-free periods. For an individual with motor and / or vocal tics of less than 1 year since first tic onset, a provisional tic disorder diagnosis can be considered. There is no duration specification for other specified and unspecified tic disorders. The onset of tics must occur prior to age 18 years (Criterion C). Tic disorders typically begin in the prepubertal period, with an average age at onset between 4 and 6 years, and with the incidence of new-onset tic disorders decreasing in the teen years. New onset of tic symptoms in adulthood is exceedingly rare and is often associated with expo- sures to drugs (e.g., excessive cocaine use) or is a result of a central nervous system insult (e.g., postviral encephalitis). Although tic onset is uncommon in teenagers and adults, it is not uncommon for adolescents and adults to present for an initial diagnostic assessment and, when carefully evaluated, provide a history of milder symptoms dating back to child- hood. New-onset abnormal movements suggestive of tics outside of the usual age range should result in evaluation for other movement disorders or for specific etiologies.
Tic symptoms cannot be attributable to the physiological effects of a substance or an- other medical condition (Criterion D). When there is strong evidence from the history, physical examination, and / or laboratory results to suggest a plausible, proximal, and probable cause for a tic disorder, a diagnosis of other specified tic disorder should be used.
agnosis of persistent (chronic) motor or vocal tic disorder (Criterion E). Similarly, a previ- ous diagnosis of persistent (chronic) motor or vocal tic disorder negates a diagnosis of provisional tic disorder or other specified or unspecified tic disorder (Criterion E).