Background: Our study was conducted to characterize sensory phenomena experienced by Gilles de la Tourette's syndrome (TS) sufferers. Specific foci of the study were premonitory urges associated with motor and phonic tics, site sensitization, and disinhibition behaviors.

Method: Twenty-eight subjects were recruited for participation in the study from the Tourette's Syndrome Association and from neurologists' patient lists. All had been diagnosed as having TS at least 2 years prior to the study. Patients were contacted by telephone and questioned in an attempt to screen for participants who experienced some sensory phenomena preceding or accompanying their tics. Interviews were conducted in person with 27 of the participants and by telephone with 1 participant.

Results: Twenty-two (82%) of the 28 subjects experienced premonitory urges prior to motor and vocal tics. Of these 22, 13 (57%) found the premonitory urges more bothersome than the tics themselves, and 12 (55%) thought the premonitory urges enhanced their ability to suppress tics. Of 20 subjects questioned about site sensitization, 14 (70%) had heightened sensitivity to tactile, auditory, and/or visual stimuli. Disinhibition-complex behaviors the subject knows are dangerous or inappropriate but feels incapable of refraining from--was found in 10 (36%) of the 28 subjects and occurred only in subjects experiencing premonitory urges. Premonitory urges and site sensitivity can occur alone or together. Several excellent narrative descriptions of sensory phenomena associated with TS were also obtained.

Conclusion: Much information was gained that adds to the ongoing attempt to characterize sensory phenomena associated with TS. The sensory phenomena must be understood by clinicians who treat TS sufferers, as this study shows that they add significantly to the impairment caused by TS.