A team of international researchers, led by Dr. Kevin W. McCairn, Ph.D. has announced the discovery of a system in the brain that may underlie the development of involuntary vocalizations (commonly called vocal tics) that often occur in people with Tourette syndrome. The study is published in the January 2016 issue of the journal Neuron 89(2) and was supported by the Tourette Association of America.
“The findings from this group of researchers will help to explain how vocals tics develop which can be a significant problem for individuals with TS and related disorders,” said Kevin McNaught, Ph.D., Executive Vice President, Research and Medical Programs, Tourette Association of America.
Tourette syndrome (TS) and other Tic disorders are neurodevelopmental conditions that affect 1 in 100 school-aged children, as well as a significant number of adults in the United States. These disorders are defined by complex patterns of involuntary movements and sounds called tics. The latter can range from simple sounds to complex vocalizations, such as coprolalia, which is the utterance of words and phrases that can be obscene and socially unacceptable. These symptoms are difficult to manage due to a lack of effective treatments and represent a significant source of challenge for people with TS.
Dr. McCairn and his team at the Korea Brain Research Institute – Korea, in collaboration with researchers at the National Institute of Radiological Science – Japan, Primate Research Institute – Kyoto University, RIKEN, Kansai and Tsukuba University, used PET imaging experiments to monitor metabolic activity in the brain of non-human primates as different regions were stimulated to induce vocal tics. It was found that a network called the limbic system, a region of the brain that is involved in emotional processing, exhibited very high activity suggesting that it plays a role in vocal tic generation. These findings are in line with previous findings from Tourette Association of America funded research on motor tics, conducted by Dr. McCairn and Dr. Bar-Gad at Bar Ilan University, Israel.
Dr. McCairn said “Identification of the brain regions and mechanisms that control the abnormal vocalizations associated with TS has been a goal of researchers and clinicians since the initial description of the disorder by Gilles de La Tourette in the 19th century. A reproducible model of these behaviors now provides an opportunity to more fully understand how the disease affects the brain and provides a platform on which to test new treatments.”
About Tourette Syndrome:
Tourette Syndrome (TS) is part of a spectrum of hereditary, childhood-onset, neurodevelopmental conditions referred to as Tic Disorders. These conditions affect both children and adults, causing them to make sudden, uncontrollable movements and sounds called tics. Today it is estimated that 1 in 100 school-aged children in the United States has TS or another Tic Disorder.
- Phonic tics are involuntary sounds or vocalizations. Common simple vocal tics may include sniffing, throat clearing, grunting, hooting or shouts. In a minority of cases, these words may be profane (i.e., swear words, ethnic slurs and other socially unacceptable words or phrases). This type of vocal tic is called coprolalia and is often portrayed or made fun of in the media. However, only a small proportion of those with TS experience this symptom.
- Motor tics are movements that can affect different parts of the body. Common simple motor tics may include eye blinking, facial grimacing, jaw movements, head bobbing or jerking, shoulder shrugging, neck stretching and arm jerking.
- Non-tic features, such as Obsessive Compulsive Disorder (OCD), Attention Deficit Hyperactivity Disorder (ADHD) and learning difficulties, often develop in affected individuals. Symptoms of tic disorders can range from mild to severe and, in some cases, can be self-injurious, debilitating and markedly reduce quality of life.
About the Tourette Association of America:
Founded in 1972, the Tourette Association of America is dedicated to making life better for all individuals affected by Tourette and Tic Disorders. The only nationwide, voluntary health organization serving this community, the Association works to raise awareness, fund research and provide on-going support. The Tourette Association directs a network of 32 Chapters and more than 55 support groups across the country. Started in 1984, The Tourette Association of America’s grants program has been funding basic and clinical research on all aspects of Tourette and Tic Disorders. For more information on Tourette and Tic Disorders, call 1-888-4-TOURET, visit http://tourette.org, on Facebook, Twitter and on YouTube.