Tourette's Syndrome is a neurological condition characterized by tics and typically diagnosed during childhood or early adolescence. The American Psychiatric Association defines a tic as a "sudden, rapid, recurrent, nonrhythmic, stereotyped motor movement or vocalization." Tourette's involves both motor and vocal tics. Coprolalia, the vocalization of obscenities, is an uncommon tic, and less than 10 percent of Tourette's sufferers utter obscenities as a result of the disorder.
Dopamine
Tourette's has no known cause. However, the neurotransmitter dopamine, which is responsible for initiation of movement, may be involved. According to an article in the February 2010 issue of "Annals of Neurology," certain parts of the brains of patients with Tourette's show abnormalities in the transmission of dopamine. Specifically, people with Tourette's have a hypersensitivity to dopamine, and increased dopamine can increase the frequency and severity of tics.
Caffeine
People with Tourette's should avoid caffeine, because it increases the production of dopamine and the frequency of tics. The impact of caffeinated beverages on tics in people with Tourette's was the focus of a 2008 study conducted in Germany. Self-report questionnaires from over 200 patients with Tourette's were analyzed. Researchers found a significant relationship between caffeine consumption and worsened tics. Specifically, coffee, Coke and black tea were positively related to tic deterioration. In fact, 34 percent of subjects reported that coffee exacerbated their tics, and 47 percent of subjects reported the same about Coke.
Treatment
Tourette's is a chronic, lifelong condition. In general, symptoms are worst during early adolescence, improve during late adolescence and continue throughout adulthood, according to the National Institute of Neurological Disorders and Stroke. Symptoms of Tourette's usually do not significantly impair a person's ability to function. Therefore, most people with Tourette's do not need medication. When impairment is substantial, neuroleptic medications are used to reduce tic frequency and severity. The two most common neuroleptics used to treat Tourette's are haloperidol and pimozide.
Side Effects
Neuroleptic medications like haloperidol and pimozide are dopamine antagonists. They block dopamine receptors in the brain to modulate dopamine levels. However, neuroleptics have numerous side effects, such as sedation, weight gain, tremor, Parkinsons-like symptoms and involuntary muscle movements. These side effects typically resolve with the reduction of the medication. Chronic use of these medications can cause withdrawal symptoms, such as the re-emergence of tics and tardive dyskinesia, a movement disorder.
References
- Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision; Tourette's Disorder; American Psychiatric Association; 2000
- National Institute of Neurological Disorders and Stroke: Tourette Syndrome Fact Sheet
- Acta Paediatria; The Influence of Different Food and Drink on Tics in Tourette Syndrome: K.R. Müller-Vahl, et al.; April 2008
- Annals of Neurology; Extrastriatal Dopaminergic Dysfunction in Tourette Syndrome. T.D. Steeves; February 2010
- Expert Opinion on Pharmacotherapy; Management of tics and Tourette's disorder: an update; D.P. Bestha, et al.; August 2010
