Clinical features associated with an early onset in chronic tic disorders.

In chronic tic disorders such as Tourette syndrome (TS), tics often appear between 4 and 8 years but they can also appear in early childhood, a period in which symptom expression may be affected by early brain development. The present study examined whether symptom expression in early-onset TS was distinct from that observed in TS with a later onset. We compared the clinical characteristics in children with TS who developed tics before age 4 or after age 6. Early-onset TS was significantly associated with an increased rate of stuttering and other speech disfluencies as well as an increased rate of oppositional defiant disorder, symptoms that often appear before age 4. Early-onset TS was also linked to maternal transmission of tics. Early-onset TS was not significantly associated with tic severity, obsessive-compulsive behavior or attention-deficit hyperactivity disorder. The results suggest that an early onset affects symptom expression in tic disorders.