Tests and diagnosis
By Mayo Clinic staffThere's no specific test that can diagnose Tourette syndrome. Instead, doctors must rely on the history of the person's symptoms to diagnose the disorder.
The Diagnostic and Statistical Manual of Mental Disorders (DSM) determines the criteria for a diagnosis of Tourette syndrome. Published by the American Psychiatric Association, the DSM is used by mental health professionals to diagnose certain conditions and by insurance companies to reimburse for treatment.
The criteria to diagnose Tourette syndrome include:
- Both motor tics and vocal tics must be present, although not necessarily at the same time.
- Tics occur several times a day, nearly every day or intermittently, for more than a year. There must not be a break in tics for more than a three-month period.
- The onset of tics occurs before age 18.
- Tics aren't caused by medications, other substances or another medical condition.
Diagnosis of Tourette syndrome may be delayed because families and even doctors are sometimes unfamiliar with the symptoms or the symptoms may mimic other problems. Eye blinking may be initially associated with vision problems, for instance, while sniffing may be attributed to allergies.
Because tics and movement problems can be the result of other serious health conditions, your doctor may suggest having tests to rule out other problems. These tests include blood tests or neuroimaging studies, such as magnetic resonance imaging (MRI).
- Tourette syndrome. Centers for Disease Control and Prevention. www.cdc.gov/ncbddd/tourette/default.htm. Accessed Jan. 10, 2010.
- Jankovic, J. Tourette syndrome. http://www.uptodate.com/home/index.html. Accessed Jan. 11, 2010.
- Tourette syndrome fact sheet. National Institute of Neurological Disorders and Stroke. http://www.ninds.nih.gov/disorders/tourette/detail_tourette.htm. Accessed Jan. 10, 2010.
- Tourette syndrome. Genetics Home Reference. http://ghr.nlm.nih.gov/condition=tourettesyndrome/show/print. Accessed Jan. 22, 2010.
- Cavanna AE, et al. The behavioral spectrum of Gilles de la Tourette syndrome. The Journal of Neuropsychiatry and Clinical Neurosciences. 2009;21:13.
- Tourette syndrome: Frequently asked questions. Tourette Syndrome Association. http://www.tsa-usa.org/Medical/Faqs.html. Accessed Jan. 22,2010.
- Conolea CA, et al. The influence of contextual factors on tic expression in Tourette's syndrome: A review Journal of Psychosomatic Research. 2008;65:487.

Find Mayo Clinic on