Looking at Links Between Tourette Syndrome and Strep Throat
Almost all school-aged children get infected with strep throat at some point in their lives. For some children with Tourette syndrome (TS), strep throat may be even more likely and more troublesome, according to preliminary results from two multicenter studies.
Dr. Gilbert is shown here using a Transcranial Magnetic Stimulation (TMS) machine to measure the brain's electrical activity for his research into Tourette syndrome.
The studies were designed to understand a link between strep infections and tics or obsessive compulsive disorder (OCD) symptoms – a condition referred to as Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections (PANDAS). The investigators studied about 150 children with TS, including 30 families at Cincinnati Children's Hospital Medical Center. "The data have only been partially analyzed," notes Donald Gilbert, MD, MS, director of the Movement Disorder Clinic and Tourette Syndrome Clinic at Cincinnati Children's, "but it appears that some of the kids with TS are abnormally prone to get infected with strep and that they are also abnormally prone to have sudden, severe worsening of their symptoms, but that those two events aren't always linked."
More Meaningful Test
"There has to be some other test that is more meaningful," Dr. Gilbert says. "Our group has applied to the National Institutes of Health for additional research funds because we have some ideas about what those tests might be, more specific blood tests for immune system mechanisms that may affect dopamine in the brain. That would potentially be a very exciting link between the immune system and problems with tics and other behaviors if we can validate that." Dr. Gilbert has been studying dopamine and other neurotransmitters for their possible link to TS and attention deficit hyperactivity disorder (ADHD). Many children with TS also have ADHD and both are considered "highly heritable," Dr. Gilbert says, although no specific genes have been shown to cause or worsen either TS or ADHD.
By "determining what functions within the immune system can be triggered by strep and other infections to cross into the brain to produce tics and OCD," Dr. Gilbert notes, the proposed study can help "identify which kids should be the target of strep prevention or infection prevention, or potential therapies that target those problems in the immune system." More targeted approaches would avoid the use of broad spectrum system immune system suppressants that can be costly and have harmful side effects.
Improve with Age
In most children with TS, the symptoms are mild, do not require any specific treatment and improve with age. "A majority of patients will tic less as adults than they did as children, and by majority we mean somewhere in the neighborhood of 90 percent," Dr. Gilbert reports.
At the Tourette Syndrome Clinic at Cincinnati Children's "we treat children and adults with Tourette syndrome as well as provide education to the families about the symptoms and prognosis. If symptoms are mild, we encourage them to reconsult us if the symptoms get worse and cause problems with the child," Dr. Gilbert says. If the child also has ADHD or OCD, Dr. Gilbert may advise the primary physician treating the child about best practices for those conditions in children with TS.
Dr. Gilbert is director of the Movement Disorder Clinic and Tourette Syndrome Clinic. Publications reporting his research include Brain (129:2038-2046, 2006), Neurology (67: 1695-1697, 2006), and American Journal of Medical Genetics, Part B: Neuropsychiatric Genetics (2007, in press). Results of the Tourette Syndrome Study Group's intensive study of streptococcal infections and exacerbations of tics and obsessive compulsive disorder was presented at the Annual Meeting of the Pediatric Academic Society, Toronto, Canada, on May 5, 2007.
