**2.1.1 Differential diagnosis**

Simple motor tics may need to be differentiated from myoclonic jerks, which are not typically repetitive in the same body part like tics. Tics are commonly associated with premonitory sensations and suppressibility. Complex motor tics need to be distinguished from stereotypies that are longer lasting, more stereotyped movements (*eg*, body rocking, head nodding, and hand/wrist flapping) or sounds (eg, moaning, yelling) that occur over and over again in a more continuous, less paroxysmal fashion. Stereotypies are typically seen in patients with autism, mental retardation, Down syndrome, Rett syndrome, psychosis, or congenital blindness and deafness.

Some tics are slow or twisting in character resembling dystonia and are termed ''dystonic tics". Contrary to dystonic tics, dystonia *per se* tends to beslower and leads to more sustained disturbances in posture of a limb, the neck, or trunk. Compulsions frequently occur in association with tics, can sometimes be difficult to distinguish from complex motor tics but typically differ by being done in response to an obsession, being performed to avoid future problems or being done according to ritualistic rules5 6 With very high comorbidity rates of both ADHD and OCD, GTS may represent a multifaceted developmental neuropsychiatric brain disorder7.
