Executing motor tics in response to experimentally generated urges reduces subjective inconvenience but potentiates their physiological impact.

Abstract

OCD patients attempt to alleviate uncertainty (is the door closed) by perseveration, such as extensive checking rituals, with counterproductive, paradoxical results: feelings of uncertainty usually increase. In a similar vein, Tourette Syndrome patients respond to premonitory urges with tics, and claim that these urges are relieved by executing the tic. Analogue to findings in OCD, it was hypothesized whether similar paradoxical effects occur in TS. In healthy participants, it was investigated whether deliberately executing a motor tic in response to experimentally induced sensations in the same region sensitizes to these sensations, both subjectively as well as physiologically. Against hypothesis, findings suggest that tics are rewarded as they subjectively reduce the subjective annoyance of future urges as well as the tendency to respond to them. However, physiological measures indicate that executing tics ultimately results in increased physiological activity in the tic region compared to a control condition, possibly representing a sensitisation to the stimuli, or a failure to habituate to future urges.