Repetitive and restricted behaviors, habits, body-focused repetitive behaviors, and motor stereotypies.

Movement disorder definitions that include the clinical characteristics "sudden, rapid, repetitive, brief, and involuntary" are not limited to motor tic disorders. Hence, it is essential that caregivers be aware of other relatively common conditions that could be confused with the diagnosis of tics. Included in this differential are entities such as repetitive and restricted behaviors (RRBs), habits, body-focused repetitive behaviors (BFRBs), and motor stereotypies. The importance of separation of these individual conditions is further emphasized by the recognition that they can be coexisting problems in individuals with tic disorders, and thus therapeutic approaches may differ. For example, some individuals diagnosed with Tourette syndrome have co-occurring complex motor stereotypies or recurring skin picking, nail biting, and hair pulling. This chapter reviews the definition of a movement disorder and the evolving entity labeled as RRBs. It also contains a more in-depth review of our knowledge regarding the clinical features, etiology, pathophysiology, and therapeutic approaches for the more specific diagnoses including habits, BFRBs, and stereotypies.