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Tourette syndrome (TS) is a neurological disorder characterized by repetitive, stereotyped, involuntary movements and vocalizations called tics. The disorder is named for Dr. Georges Gilles de la Tourette, the pioneering French neurologist who in 1885 first described the condition in an 86-year-old French noblewoman.
The early symptoms of TS are typically noticed first in childhood, with the average onset between the ages of 3 and 9 years. TS occurs in people from all ethnic groups; males are affected about three to four times more often than females. It is estimated that 200,000 Americans have the most severe form of TS, and as many as one in 100 exhibit milder and less complex symptoms such as chronic motor or vocal tics. Although TS can be a chronic condition with symptoms lasting a lifetime, most people with the condition experience their worst tic symptoms in their early teens, with improvement occurring in the late teens and continuing into adulthood.
What are the symptoms?
Tics are classified as either simple or complex. Simple motor tics are sudden, brief, repetitive movements that involve a limited number of muscle groups. Some of the more common simple tics include eye blinking and other eye movements, facial grimacing, shoulder shrugging, and head or shoulder jerking. Simple vocalizations might include repetitive throat-clearing, sniffing, or grunting sounds. Complex tics are distinct, coordinated patterns of movements involving several muscle groups. Complex motor tics might include facial grimacing combined with a head twist and a shoulder shrug. Other complex motor tics may actually appear purposeful, including sniffing or touching objects, hopping, jumping, bending, or twisting. Simple vocal tics may include throat-clearing, sniffing/snorting, grunting, or barking. More complex vocal tics include words or phrases. Perhaps the most dramatic and disabling tics include motor movements that result in self-harm such as punching oneself in the face or vocal tics including coprolalia (uttering socially inappropriate words such as swearing) or echolalia (repeating the words or phrases of others). However, coprolalia is only present in a small number (10 to 15 percent) of individuals with TS. Some tics are preceded by an urge or sensation in the affected muscle group, commonly called a premonitory urge. Some with TS will describe a need to complete a tic in a certain way or a certain number of times in order to relieve the urge or decrease the sensation.
Tics are often worse with excitement or anxiety and better during calm, focused activities. Certain physical experiences can trigger or worsen tics, for example tight collars may trigger neck tics, or hearing another person sniff or throat-clear may trigger similar sounds. Tics do not go away during sleep but are often significantly diminished.
What is the course of TS?
Tics come and go over time, varying in type, frequency, location, and severity. The first symptoms usually occur in the head and neck area and may progress to include muscles of the trunk and extremities. Motor tics generally precede the development of vocal tics and simple tics often precede complex tics. Most patients experience peak tic severity before the mid-teen years with improvement for the majority of patients in the late teen years and early adulthood. Approximately 10-15 percent of those affected have a progressive or disabling course that lasts into adulthood.
What causes TS?
Although the cause of TS is unknown, current research points to abnormalities in certain brain regions (including the basal ganglia, frontal lobes, and cortex), the circuits that interconnect these regions, and the neurotransmitters (dopamine, serotonin, and norepinephrine) responsible for communication among nerve cells. Given the often complex presentation of TS, the cause of the disorder is likely to be equally complex.
How is TS treated?
Because tic symptoms often do not cause impairment, the majority of people with TS require no medication for tic suppression. However, effective medications are available for those whose symptoms interfere with functioning. Neuroleptics (drugs that may be used to treat psychotic and non-psychotic disorders) are the most consistently useful medications for tic suppression; a number are available but some are more effective than others (for example, haloperidol and pimozide).
Unfortunately, there is no one medication that is helpful to all people with TS, nor does any medication completely eliminate symptoms. In addition, all medications have side effects. Many neuroleptic side effects can be managed by initiating treatment slowly and reducing the dose when side effects occur. The most common side effects of neuroleptics include sedation, weight gain, and cognitive dulling. Neurological side effects such as tremor, dystonic reactions (twisting movements or postures), parkinsonian-like symptoms, and other dyskinetic (involuntary) movements are less common and are readily managed with dose reduction.
Discontinuing neuroleptics after long-term use must be done slowly to avoid rebound increases in tics and withdrawal dyskinesias. One form of dyskinesia called tardive dyskinesia is a movement disorder distinct from TS that may result from the chronic use of neuroleptics. The risk of this side effect can be reduced by using lower doses of neuroleptics for shorter periods of time.
Other medications may also be useful for reducing tic severity, but most have not been as extensively studied or shown to be as consistently useful as neuroleptics. Additional medications with demonstrated efficacy include alpha-adrenergic agonists such as clonidine and guanfacine. These medications are used primarily for hypertension but are also used in the treatment of tics. The most common side effect from these medications that precludes their use is sedation. However, given the lower side effect risk associated with these medications, they are often used as first-line agents before proceeding to treatment with neuroleptics.
Effective medications are also available to treat some of the associated neurobehavioral disorders that can occur in patients with TS. Recent research shows that stimulant medications such as methylphenidate and dextroamphetamine can lessen ADHD symptoms in people with TS without causing tics to become more severe. However, the product labeling for stimulants currently contraindicates the use of these drugs in children with tics/TS and those with a family history of tics. Scientists hope that future studies will include a thorough discussion of the risks and benefits of stimulants in those with TS or a family history of TS and will clarify this issue. For obsessive-compulsive symptoms that significantly disrupt daily functioning, the serotonin reuptake inhibitors (clomipramine, fluoxetine, fluvoxamine, paroxetine, and sertraline) have been proven effective in some patients.
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