The researchers found that cognitive behavioral therapy normalized activity in the supplementary motor area of the brains of study participants with Tourette syndrome.
The findings of the study will be presented at the First World Congress on Tourette Syndrome and Tic Disorders in London, UK, and could have implications for the future treatment of people with the neuropsychiatric disorder.
Tourette syndrome is an inherited tic disorder characterized by motor and vocal tics - repetitive semi-voluntary movements or vocalizations with no apparent purpose.
"There is still no definitive explanation of the causes of this syndrome, but we know that tics are related to an impaired communication between the supplementary motor area - a region of the cerebral cortex - and deeper areas called the basal ganglia," said Simon Morand-Beaulieu, a student in the Department of Neuroscience at the University of Montreal, Canada.
Many people do not require any treatment for Tourette syndrome, but for some the tics can be disruptive and can - for young people in particular - make learning and socializing difficult. For these individuals, certain forms of treatment are available, including cognitive behavioral therapy (CBT).
CBT is a blend of cognitive therapy and behavioral therapy that focuses on helping people to focus on their problems and how they might solve them, assisting them to identify problematic forms of behavior and change them.
In people with Tourette syndrome, CBT helps to normalize activity in the supplementary motor region of the brain by utilizing relaxation and exercises targeting muscles associated with tics.
"In addition to the beneficial effects on tics, we wanted to see if CBT effectively alters the brain function of people with [Tourette syndrome]," says Morand-Beaulieu.
CBT affected supplementary motor region but not frontal region activity
For the study, participants with Tourette syndrome completed a task designed to prompt activity in the supplementary motor region of the brain. The task involved responding to the color of an arrow that was pointing to the left or the right.
The researchers noted overactivity in the supplementary motor region while there were deficits in the appropriate selection and preparation of the participants' physical responses.
Following this task, the participants with Tourette syndrome received CBT and then later repeated the task. The researchers found that not only were the Tourette syndrome tics reduced, but the brain functioning of the participants in the supplementary motor region was similar to that of participants without Tourette syndrome.
Interestingly, the researchers also observed overactivity in the frontal region of the brains of the participants with Tourette syndrome when movement was inhibited. This overactivity was present both before and after CBT.
"This could be an adaptive mechanism deriving from the patients' experience of inhibiting their own tics," explains study supervisor Marc Lavoie, a researcher at the Institut universitaire en sane mental de Montréal. "As a result, they are able to perform as well as participants without [Tourette syndrome] during tasks requiring cognitive control, but at the cost of greater frontal cortex activity."
The researchers believe that their findings will help improve therapeutic strategies for Tourette syndrome and have a practical impact on the quality of life for people with the disorder.
"It will soon be possible to share this neurophysiological data with psychologists conducting CBT and thus correct or enhance treatment of people affected by [Tourette syndrome]," Lavoie concludes.
Previously, Medical News Today reported on a study identifying a chemical in the brain called GABA that could play a major role in controlling tics associated with Tourette syndrome.