People with Tourettes struggle with uncontrollable physical tics and verbal outbursts. But a new study reveals that they also have highly developed cognitive control over their reactions. University of Nottingham's Stephen Jackson examined brain scans of people with Tourettes, and says:
The motor outputs of children with Tourettes syndrome are under greater cognitive control. You might view this as their being less likely to respond without thinking, or as being less reflexive.
This helps explain why some people may have many tics as children, but as adults have very few. Over time, their brains have developed ways to control these tics. Jackson points out that this may mean people with Tourettes need mental exercises rather than brain surgery or drugs, because their brains will naturally develop compensatory mechanisms.
Jackson and colleagues also discovered that people with Tourettes have unusual brain anatomy. According to a release about their study, published today in Current Biology:
The Tourettes brain shows alterations in the white-matter connections that allow different brain areas to communicate with one another, Jackson said. Brain scans also revealed changes in activity as indicated by blood flow when people with Tourette syndrome performed an executive function task.
The structural and functional changes observed were also strongly associated with clinical measurements of tic severity and executive function. In particular, the researchers found that changes in the frontal cortex of the Tourettes brain, the region most often linked to executive function, are strongly linked to levels of tic severity and executive task performance. They interpret this as evidence that the frontal cortex of the Tourette syndrome group reorganizes to help control the motor and vocal tics.
"Children growing up with a neurological disorder may develop adaptive changes in the way that their brain is organized that will help them overcome their difficulties and gain control over their symptoms," Jackson said.
It's not clear whether all people who suffer from Tourettes will grow these white matter structures, or gain the ability to control their tics. But many can.
Read the full scientific article at Current Biology