By Michelle Jaffee
Significant progress has been made in understanding the genetics and pathophysiology of Tourette syndrome and in refining treatments, yet several unsolved challenges remain, according to a new review by University of Florida neuroscientists and biomedical engineers. The review, published in the journal Lancet Neurology, provides an overview of clinical features and treatments for the childhood-onset neurodevelopmental disorder.
Tourette syndrome, which is characterized by involuntary motor and vocal tics, affects an estimated 350,000 to 450,000 children and adults in the U.S., according to researchers.
Led by biomedical engineer and postdoctoral associate in the department of neurology Kara Johnson, Ph.D.; Aysegul Gunduz, Ph.D., associate professor of biomedical engineering; and Michael Okun, M.D., chair of neurology and executive director of the Norman Fixel Institute for Neurological Diseases at UF Health, the review focuses on research from the past five years, including novel drug therapies, and highlights key questions for future research.
“International, multicenter partnerships have transformed genetic research, and as a result, new gene variants have been identified that may be associated with an increased risk of Tourette syndrome,” said Johnson, the paper’s lead author. “These gene variants could be relevant for diagnosis or developing novel therapeutic targets in the future.”
In addition, a multicenter consortium is expanding research into deep brain stimulation, or DBS, for patients who have severe cases of Tourette that do not respond to first-line therapies. DBS is not approved by the U.S. Food and Drug Administration to treat Tourette syndrome.
Using the International Tourette Syndrome Database and Registry, led by Okun, the authors have identified new predictors that could underlie variability in outcomes of DBS for Tourette syndrome that does not respond to medicines or behavioral treatment.
“Specific brain networks modulated by DBS, combined with novel investigational tools such as DBS devices capable of chronic recordings, may improve the efficacy of DBS for Tourette syndrome,” Johnson said.
Future research, she said, could provide insights to further refine treatments based on patient-specific genetics and symptom profiles.
One key to overcoming unsolved challenges will be aggregating data across centers, the authors wrote. “Several research organizations and multicenter consortia have been established to pool data, resources and multidisciplinary expertise across Tourette syndrome research domains,” according to the article.
“Future research should aim to further our understanding of the pathophysiology of Tourette syndrome and translate this knowledge to refine therapies,” the authors wrote. “To develop more effective treatments, we will need a clearer understanding of the clinical subtypes of Tourette syndrome … which could be stratified using common symptoms across diagnoses, genetics, neuroimaging, or neurophysiological measures.”