Brain mechanisms for prepulse inhibition in adults with Tourette syndrome: Initial findings

Nazlee Zebardast, Michael J. Crowley, Michael H. Bloch, Linda C. Mayes, Brent Vander Wyk, James F. Leckman, Kevin A. Pelphrey, James E. Swain

Research output: Contribution to journalArticle

Abstract

Prepulse inhibition (PPI) of the startle reflex is disrupted in a number of developmental neuropsychiatric disorders, including Tourette syndrome (TS). This disruption is hypothesized to reflect abnormalities in sensorimotor gating. We applied whole-brain functional magnetic resonance imaging (fMRI) to elucidate the neural correlates of PPI in adult TS subjects using airpuff stimuli to the throat to elicit a tactile startle response. We used a cross-sectional, case-control study design and a blocked-design fMRI paradigm. There were 33 participants: 17 with TS and 16 healthy individuals. As a measure of PPI-related brain activity, we looked for differential cerebral activation to prepulse-plus-pulse stimuli versus activation to pulse-alone stimuli. In healthy subjects, PPI was associated with increased activity in multiple brain regions, of which activation in the left middle frontal gyrus in the healthy controls showed a significant linear correlation with the degree of PPI measured outside of the magnet. Group comparisons identified nine regions where brain activity during PPI differed significantly between TS and healthy subjects. Among the TS subjects, activation in the left caudate was significantly correlated with current tic severity as measured by the total score on the Yale Global Tic Severity Scale. Differential activation of the caudate nucleus associated with current tic severity is consistent with neuropathological data and suggests that portions of cortical-striatal circuits may modulate the severity of tic symptoms in adulthood.

Original languageEnglish (US)
Pages (from-to)33-41
Number of pages9
JournalPsychiatry Research - Neuroimaging
Volume214
Issue number1
DOIs
StatePublished - Oct 30 2013

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Keywords

  • Adults
  • Brain mechanisms
  • Cortico-striatal circuits
  • Prepulse inhibition
  • Sensorimotor gating
  • Tourette syndrome

ASJC Scopus subject areas

  • Neuroscience (miscellaneous)
  • Radiology Nuclear Medicine and imaging
  • Psychiatry and Mental health

Cite this

Zebardast, N., Crowley, M. J., Bloch, M. H., Mayes, L. C., Wyk, B. V., Leckman, J. F., Pelphrey, K. A., & Swain, J. E. (2013). Brain mechanisms for prepulse inhibition in adults with Tourette syndrome: Initial findings. Psychiatry Research - Neuroimaging, 214(1), 33-41. https://doi.org/10.1016/j.pscychresns.2013.05.009