Tourette’s syndrome

A neurological disorder characterised by multiple involuntary motor tics mostly in the face and neck muscles (e.g., eye blinking, nose twitching, shoulder shrugs), but also in other body parts (e.g., arm thrusting, leg kicks, jumping movements)  and a least one vocal tic (e.g., barking, grunting, sniffing noises). Reputedly, Wolfgang Amadeus Mozart (1756-1791) had the syndrome as did Samuel Johnson (1709-1784), and a more contemporary sufferer is Tim Howard, a goalkeeper for Manchester United. While it is most often associated with swearing (coproalia), only about 15% of cases actually have outbursts of obscene language. Most individuals with the syndrome are impulsive, and show other signs of ADHD, with an obsessive-compulsive disorder constituting another co-morbidity. Unlike most serious motor system disorders, there is no evidence associating the syndrome with cognitive impairments, and it still unclear as to whether the syndrome constitutes neuropathology, but there is some evidence to suggest that the tics are a product of an increased sensitivity to dopamine, and by the fact they can be controlled by treatment with drugs such as haloparidol that block dopamine receptors. Although first described in 1825 by Jean Marc Gaspard Itard (1774-1838), it is named after the physician Georges Gilles Albert Edouard Brutus de la Tourette (1859-1904) who presented it in more detail in 1885. Its prevalence is conservatively estimated at 2% of the general population. With an onset usually around the age of six years, it affects one to five people per 10,000, with males outnumbering females by about four to one. This sex difference has led to research on the possible role of prenatal hormones in the syndrome. One speculation to emerge from such research is that that surges of testosterone and other androgens during particular periods in fatal neural development may predispose males to acquire tics after birth. Twin studies have also revealed an important hereditary component to the syndrome (e.g., there is about a 50% chance of inheriting it if the father has it). Brain imaging research (both fMRI and volumetric sMRI) has revealed a number abnormalities in patients with Tourette‚was syndromevolume reductions in size of the putamen, globus pallid us and reticular zone in the basal ganglia, decreased uptake of glucose and decreased regional blood flow in the basal ganglia, abnormal volume relationships in the lateral ventricles and corpus callosum, and damage to the cingulate cortex. All told, the most consistent abnormality found has to do with dysfunctions in the dopaminergic pathways. Some confusion exists about the diagnosis of tic disorders in DSM-IV (Criterion C), namely, that they required ‚aa‚a¶ significant distress or impairment‚aa (pp. 101, 103-105). Judged to be unworkable, Criterion C was removed from the Text Revision of DSM-IV, but without mention of this important change. The necessity to cite DSM-IV-TR, rather than DSM-IV, in studies involving patients with Tourette’s syndrome was made in the following published letter to the editor

Freeman, R. (2005). Diagnostic criteria for Tourette‚aas disorder. Journal of American Academy of Child & Adolescent Psychiatry, 44, 209-210.

See Attentional deficit hyperactive disorder (ADHD), Basal ganglia, Co-morbidity, Dopamine, Echolalia, Motor inhibition, Obsessive-compulsive disorder, Prefrontal-frontal-striatal loops