Which findings on functional imaging studies correlate with tic severity or tic suppression in Tourette syndrome (TS) and other tic disorders?

Updated: May 30, 2019
  • Author: William C Robertson, Jr, MD; Chief Editor: Stephen L Nelson, Jr, MD, PhD, FAACPDM, FAAN, FAAP  more...
  • Print
Answer

In an fMRI study, self-rated intensity of the current urge to tic was correlated with right caudate BOLD signal intensity. [59] Findings also implicated the cingulate cortex.

Similar results emerged from a PET study in which regional cerebral blood flow was correlated with tic frequency in individuals with TS. [60] In this study, atlas-normalized blood flow was searched voxel by voxel for within-subject correlations with the number of tics observed during each of several blood flow scans; tics were associated not only with the expected increased activity in primary motor cortex but also with altered activity in more sensory or volitional brain regions, such as anterior cingulate.

In a [18 F]fluorodeoxyglucose (FDG) PET study, caudate and thalamus metabolism was inversely correlated with clinical severity. [61]

A case report described fMRI correlates of coprolalia in 1 subject with TS. The results offered support to the hypothesis of a tic-generating circuit model. [62] In ongoing fMRI studies, Stuart Mostofsky at the Kennedy Krieger Institute uses the important control of intentional tic-like movements in people with TS.


Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!