Overview
Identify motor and vocal tics from their urge, stereotypy and suppressibility, diagnose Tourette syndrome longitudinally, assess comorbid ADHD and obsessive-compulsive symptoms, and reserve treatment for meaningful distress or impairment.
Motor tics range from eye blinking and facial movements to head jerks, shoulder elevation, jumping or complex sequences. Vocal or phonic tics include sniffing, coughing, throat clearing, squeaks, words and, less commonly, socially inappropriate utterances. Suppression, suggestibility and a premonitory urge help distinguish tics from chorea, dystonia, stereotypies and myoclonus, but suppression is finite and often followed by rebound. Watching a consented home video is frequently more informative than a clinic in which tics disappear.
Classification is longitudinal. Provisional tic disorder describes motor and/or vocal tics present for less than a year. Persistent motor or vocal tic disorder involves one modality, while Tourette syndrome involves both over the illness course. Onset is typically in childhood, severity often peaks in late childhood and many improve in adolescence, although adult persistence occurs. Sudden adult onset, continuous rhythmic movements, progressive weakness, cognitive decline or an exposure-linked pattern should reopen the differential.