Reactivity of Tic Observation Procedures to Situation and Setting

Abstract

Tic frequency was assessed and compared across home and clinic as well as three experimentally-manipulated situations in order to assess the phenomenon of tic reactivity. Forty-three youngsters with chronic tic disorder recruited from two geographically-distinct sites were videotaped over three weekly laboratory visits under each of the following conditions: (1) alone/camera present, (2) other present/camera present, and (3) alone/camera hidden. Contrary to expectation, more tics were observed during overt as compared to covert observation, while the presence of another person had no overall impact on tic expression. Mean tic counts obtained from clinic observation did not significantly differ from those obtained at home collected either one day before or after. Tic frequency counts were remarkably stable over the three weekly assessments both at home and clinic. Study findings are consistent with past observations that tic expression can be influenced by environmental factors and suggest the stability of tic frequency may exhibit greater temporal and setting stability than previously thought. The clinical and research implications of these results are discussed.

The influence of contextual factors on tic expression in Tourette's syndrome: A review

“…Nevertheless, these studies also have a number of limitations. First, in all but the Piacentini et al [33] study, the effects were examined in very few participants; thus, generalizability of results remains unclear. Second, the studies were conducted within relatively brief time periods, and given the fluctuating nature of tics, longer periods of observation may yield different results.…”

“…Studies utilizing experimental designs have also examined the impact of contextual antecedent stimuli on tic expression to address some of the issues raised by descriptive designs, such as self-reporting biases and an inability to experimentally examine causal relations [18,[32][33][34][35]. Frequently, these studies utilize single-case experimental designs, which are often confused with a case study design.…”

“…In a final study, Piacentini et al [33] examined the reactivity of tics to observation and the stability and variability of tics across home and clinic observation settings in children and adolescents with TS or CTD. Participants' medication dosages had to be stable for study inclusion.…”

“…These include the presence of others [32,33], academic tasks [34], ticrelated conversation [35], verbal instructions to suppress tics [18], and overt observation [33]. In addition, the methodology of these studies improves upon the limitations inherent in the earlier self-report studies [25,28] by including experimentally manipulated variables and direct observation of tics.…”

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

“…In addition, technical and logistic issues prevent their widespread use, and video-recording itself have been found to influence tic expression (Piacentini et al, 2006). It is also noteworthy that the role of premonitory urges in tic expression has hardly been addressed.…”