Subjective versus objective measures of tic severity in Tourette syndrome - The influence of environment.

The objective of this study was to examine the influence of environmental challenges on tic expression by subjective and objective measures. The study group consisted of 41 children aged 6-18 years (M=10.15, SD=2.73) with a primary diagnosis of Tourette syndrome. Subjective measures included the Functional Assessment Interview developed for this study and three standard validated instruments. The objective measure was a video-recording of the patients in five daily-life situations: watching television, doing homework, being alone, receiving attention when ticcing, and talking to a stranger. In addition, the effect of premonitory urges on assessment of tic expression was evaluated. The associations between the subjective and objective measures of tic expression were moderate to low. A significantly higher number of tics were observed in the television situation, and a significantly lower number in the alone situation, compared to the other situations. Higher levels of premonitory urge were associated with greater awareness of objectively measured tic expression. In conclusion, tic expression is significantly influenced by the environment. Subjective measures of tic expression may be misleading. These results have implications for refining the clinical assessment of tics, improving research methodology, and developing new therapeutic strategies.

Tic-related cognition, sensory phenomena, and anxiety in children and adolescents with Tourette syndrome.

BACKGROUND: Tourette syndrome is a protoypical example of developmental psychopathology, with the varying expressions of the disorder and its consequences appearing over time. Sensory urges typically appear after age 10 and are often followed by anxiety and depression. OBJECTIVE: To study the associations among tic-related cognitions, premonitory urges, and tic severity in children with Tourette syndrome at different stages of the illness. SUBJECTS: Fifty-seven consecutive patients referred to a tic disorders clinic. INSTRUMENTS: A battery of instruments was completed: Yale Global Tic Severity Scale, Premonitory Urge for Tics Scale, Screen for Child Anxiety Related Emotional Disorders, and Child Depression Inventory. To examine cognitions, a new measure was developed: the Beliefs About Tics Scale. RESULTS: Strong correlations were found between tic-related beliefs and both premonitory urges and tic-related impairments (as measured by the Yale Global Scale). Tic-related beliefs were also strongly correlated with depression in children older than 13 years but not in younger children. CONCLUSIONS: The significant correlations between tic-related cognitions, premonitory urges, and tic-related impairments in children emphasize the important role of psychological and sensory factors in the understanding of Tourette syndrome and in its treatment.