A major differential feature is that torsion dystonia is a continual hyperkinesia, usually twisting in pattern, that can result in a sustained abnormal posture. Dystonic tics are abrupt bursts of movement that are sustained in a posture, usually for a short duration. They do not tend to be continuous. The presence of the more typical clonic tics in other body regions should raise the likelihood that the sustained contractions could be dystonic tics rather than torsion dystonia. A run of simple motor tics could be considered at the borderline between simple and complex motor acts.
Complex tics are distinct, coordinated patterns of sequential movements.
They may appear purposeful, as if performing a voluntary motor act. Examples of complex tics that appear nonpurposeful include head shaking associated with shoulder shrugging, repetitive kicking of legs, and a sequential display of a variety of facial movements. All these other complex movements can sometimes be difficult to distinguish from complex motor tics, and the correct diagnosis of tics is usually made by exclusion of these other diagnoses or by finding an association with simple motor tics or vocal tics. Motor tics usually recur in the same part of the body, and multiple regions of the body can be involved. The expressions of the tics are not necessarily identical from occurrence to occurrence, even within the same body part.