Premonitory sensory phenomena and suppressibility of tics in Tourette syndrome: developmental aspects in children and adolescents.

Although premonitory sensory phenomena (PSP) and suppressibility of tics (SPT) are important in Tourette syndrome not only when behavioural therapeutic approaches in children are considered, there is a lack of developmental information on these phenomena. Therefore, a cross-sectional survey of these factors in children and adolescents was carried out. Rates of PSP and SPT were gathered using a questionnaire for the assessment of Tourette syndrome. The 254 outpatients (212 males, 42 females) with Tourette syndrome investigated had an age range of 8 to 19 years, normal intelligence, and diagnosis according to DSM-IV-TR/ICD-10. To test for developmental effects, the total group was stratified into three age groups (8 to 10, 11 to 14, and 15 to 19 years). Data were statistically evaluated using chi2 tests. Of the 254 participants, 37% reported PSP, while 64% were able to suppress their tics. Only a subgroup of 119 patients gave unequivocal answers to both questions and only 60% of these experienced both PSP and SPT. Statistically significant stepwise increases were found at two different age levels. One was around 10 years (PSP 'Yes' or 'No' and SPT), the other around age 14 (PSP 'Yes'). There was no influence of tic duration and age at tic onset on PSP/SPT. The reported data suggest that PSP is experienced rarely in younger children with Tourette syndrome and is not a necessary prerequisite for SPT. Increasing PSP with age merely seems to reflect cognitive development rather than intrinsic aspects of Tourette syndrome. In children under 10 years of age, SPT might require more awareness of tics than in older age groups. Developmental aspects of PSP and SPT should be taken into consideration when studies of cognitive behavioural treatment for children and adolescents with Tourette syndrome are planned.