Results
vocal tic, tic, tic suppression
CORTEX
Results from the RCT have been published elsewhere (Morand-Beaulieu et al., Change in tic severity from baseline to endpointThe first objective of this study was to assess if functional connectivity increased from baseline to endpoint in the CBIT group relative to TAU. Our analyses revealed no main effect of Time [CBIT did not impact tic suppression-related functional connectivity. Regarding our second objective about predicting CBIT outcome using mean connectivity within the tic suppression network, the interaction between Treatment and Baseline mean functional connectivity was not significant [Prediction of CBIT outcome using baseline functional connectivity during tic suppression. Reduction in vocal tic severity following CBIT was predicted by mean connectivity during tic suppression at baseline. However, functional connectivity did not predict the decrease in motor tic severity. CBIT, Comprehensive Behavioral Intervention for Tics; TAU, treatment-as-usual; YGTSS, Yale Global Tic Severity Scale.Supplementary analyses were performed to identify whether specific connections within the tic suppression subnetwork were mainly responsible for the relationship between baseline functional connectivity during tic suppression and decrease in vocal tic severity post-CBIT. To identify potential associations between improvement in total and motor tic severity, which could have been masked by looking at the mean connectivity of the tic suppression subnetwork, supplementary analyses were conducted with the motor and total tic scales as well. Within the CBIT group, correlations were performed between each of the 29 connections involved in the tic suppression subnetwork and the decrease in vocal, motor, and total tic severity. A Bonferroni-corrected Association between decrease in vocal tic severity post-CBIT and superior frontal gyrus – inferior parietal cortex connectivity. Supplementary analyses were performed between single connections involved in the tic suppression subnetwork and vocal tic severity decreases in the CBIT group. One connection was significant according to the Bonferroni-corrected significance threshold. Within the CBIT group, decreases in vocal tic severity from baseline to endpoint were predicted by the functional connectivity between the right superior frontal gyrus and the right inferior parietal cortex. A, anterior; L, left; P, posterior; R, right.