It ™s human nature to try to ascribe the onset of symptoms to a specific preceding event, he says. There has to be a very carefully done clinical study to determine whether that preceding event is truly linked, or whether the two events occurred simultaneously just by chance. This is especially true when dealing with a very common event like strep infection.

It ™s human nature to want a explanation. For almost every parent who recognizes tics and obsessive-compulsive behavior in their children, almost immediately, as soon as they recognize it, their minds shift into high gear, questioning why the child has these symptoms.

Kurlan says that about one in every five children has some tics at some point while growing up, and another one in five will show some obsessive-compulsive behavior. Most of these will outgrow the symptoms naturally within a few weeks or months, while generally children whose symptoms last more than a year may need treatment. He says that family history “genetics “ appears to be the biggest cause of tics and OCD.

With funding from the National Institute of Neurological Disorders and Stroke, Kurlan is now studying 80 children who have physical or vocal tics or have been diagnosed with obsessive-compulsive disorder. A team from 11 medical centers around the country is tracking the youngsters for two years, logging both strep infections and behavioral difficulties in an attempt to uncover any link between the two. Every three months the children receive a physical exam, including a blood test, regardless of how they feel, since children with strep often feel fine. In addition, nurses obtain throat cultures from the children every month, and whenever children have a sore throat, or when their obsessive-compulsive symptoms or tics worsen, doctors examine them. The study will be completed next year.