Three patients with Tourette’s syndrome (TS) and tic-related behaviors induced by external and internal stimuli are reported from the Department of Psychiatry, University College Medical School, Middlesex Hospital, London. All young adults whose tics began in childhood had developed a variety of obsessive compulsive disorders, sensory tics, reflex motor tics, or exaggerated startle responses, in response to internal (tightness in the chest) and external (people coughing or spitting) stimuli. The term “impulsions” has been used to describe these stimulus-induced behaviors which overlap with reflex tics and sensory tics. 
COMMENT. The authors use “reflex tic” to describe those in response to external stimuli (someone coughing), and “sensory tic” for those induced by sensations (tingling) felt in the soma or an internal stimulus (oneself coughing). The overlap between these various induced behaviors makes their separation difficult.