0

As time “tics” away, neuroscientists discover more each day

As part of their normal development, young children often engage in ritualistic, repetitive and even compulsive activities. Early developmental phases in humans typically involve perfectionism, attachments to favourite objects, rituals for eating, hoarding, bedtime rituals, etc. Psychologists believe that this phase and its accompanying behaviours help to reduce anxiety and help children organize, adapt to and master their environments.

Langen, a Danish psychiatrist, and his colleagues note the striking similarity between this early phase of development and the ritualistic, compulsive behaviour observed in disorders such as Tourette Syndrome, OCD and autism. They main difference is that in early development repetitive behaviour is adaptive and in brain-based disorders such as TS it causes significant impairment.

Humans aren’t the only species prone to repetitive behaviour. Repetitive behaviour is normal for several animals including birds, invertebrates, lower mammals and even, some higher mammals. While some animal repetitive behaviours or habits are innate, like mating behaviour, others, like bird songs, are learned.

For humans in fact, most of our behaviours are routine- and habit- based. Ann Graybiel, a PhD at the McGovern Institute for Brain Research, notes that “ … during much of our waking lives we act according to our habits, from the time we rise and go through our morning routines until we fall asleep after evening routines.”

Graybiel suggests that there is a common theme across animals, children, and adults with disorders such as TS and OCD: the repetitive behaviour, motor or cognitive, may be built up (at least in part) through the action of the basal-ganglia-based neural circuits. In other words, it is possible that the repetitive behaviour in question is caused by same thing within the brains of both animals and people.

So what does that mean?

Well, as neuroscientists and neurobiologists learn more about what happens in the brain circuitry to cause repetitive behaviour, they come closer to generating pharmacological strategies for reducing harmful types of repetitive behaviour, like SIBs or “self-injurious behaviours.” Put another way, neuropsychiatrists A. M. Meuhlmann & M. H. Lewis note that “we can use available information from clinical and animal models to make more precise hypotheses regarding the pathophysiology driving SIB.”

If this doesn’t make you optimistic. Consider that there is no shortage of neuroscience programs at the university and colleges level and there are several research institutes devoted to treating and understanding neurological conditions.

For example, the mission statement of St. Mary’s of Michigan Field of Neuroscience Institute is “to keep the light of progress burning bright in the battle against neurological disease.” Similarly, the Center for Brain Science at Harvard University is devoted to “understanding how neural circuits underlie neurological and psychiatric disorders.”

And advancements have already been made…

In 2011, researchers from the University of Nottingham discovered that the brains of children with TS develop in a unique, particular way that could suggest new methods of treatment. They realized that children with TS perform behavioural tests of cognitive motor control more accurately and quickly then their neurotypical peers.

Why?

Children with TS have enhanced control due to structural and functional changes in their brains that most likely result from constantly suppressing tics. Using brain scans, the research team found that the Tourette brain has alterations in white-matter connections that allow different brain areas to communicate with each other. They believe that the Tourette brain reorganizes to help control the motor and vocal tics.

One of the researchers behind this study, Stephen Jackson, told media: “Children growing up with a neurological disorder may develop adaptive changes in the way their brain is organized that help them overcome their difficulties and gain control over their symptoms.” This is a possible explanation for the decrease in tic symptoms experienced by individuals with TS as they age.

But what about those whose symptoms persist throughout adulthood?

Well, Jackson says that is could be that some people are just born with the propensity or capacity to develop particular brain white-matter connections that allow them to gain control over tics and others do not. This is the subject of his team’s next study.

The implications of these findings are many. Most importantly, these findings suggest that “brain-training approaches” may help individuals with TS gain control of their symptoms.

Sounds promising…

Leave a Reply

Your email address will not be published.