Today the full-blown case of TS is unlikely to be confused with any other disorder. However, only a decade ago TS was frequently misdiagnosed as schizophrenia, obsessive-compulsive disorder, Sydenham’s chorea, epilepsy, or nervous habits. The differentiation of TS from other tic syndromes may be no more than semantic, especially since recent genetic evidence links TS with multiple tics. Transient tics of childhood are best defined in retrospect. At times it may be difficult to distinguish children with extreme attention deficit hyperactivity disorder (ADHD) from TS.
Many ADHD hildren, on close examination, have a few phonic or motor tics, grimace, or produce noises similar to those of TS. Since at least half of the TS patients also have attention deficits and hyperactivity as children, a physician may well be confused. However, the treating doctor should be aware of the potential dangers of treating a possible case of TS with stimulant medication. On rare occasions the differentiation between TS and a seizure disorder may be problematic.
The symptoms of TS sometimes occur in a rather sharply separated paroxysmal manner and may resemble automatisms. TS patients, however, retain a clear consciousness during such paroxysms. If the diagnosis is in doubt, an EEG may be useful. We have seen TS in association with a number of developmental and other neurological disorders. It is possible that central nervous system injury from trauma or disease may cause a child to be vulnerable to the expression of the disorder, particularly if there is a genetic predisposition.
Autistic and retarded children may display the entire gamut of TS symptoms, but whether an autistic or retarded individual requires the additional diagnosis of TS may emain an open question until there is a biological or other diagnostic test specifically for TS. In older patients, conditions such as Wilson’s disease, tardive dyskinesia, Meige’s syndrome, chronic amphetamine abuse, and the stereotypic movements of schizophrenia must be considered in the differential diagnosis. The distinction can usually be made by taking a good history or by blood tests.
Since more physicians are now aware of TS, there is a growing danger of overdiagnosis or over-treatment. Prevailing diagnostic criteria would require that all children with suppressible multiple motor and phonic tics, owever minimal, of at least one year, should be diagnosed as having TS. It is up to the clinician to consider the effect that the symptoms have on the patient’s ability to function as well as the severity of associated symptoms before deciding to treat with medication. TABLE 1. RANGE OF SYMPTOMS OF TS Motor Simple motor tics: fast, darting, and meaningless.
Complex motor tics: slower, may appear purposeful Vocal Simple vocal tics: meaningless sounds and noises. Complex vocal tics: linguistically meaningful utterances such as words and phrases (including coprolalia, echolalia, and palilalia). Behavioral and Developmental Attention deficit hyperactivity disorder, obsessions and compulsions, emotional problems, irritability, impulsivity, aggressivity, and self- injurious behaviors; various learning disabilities Symptomatology The varied symptoms of TS can be divided into motor, vocal, and behavioral manifestations (Table 2).
Complex motor tics can be virtually any type of movement that the body can produce including gyrating, hopping, clapping, tensing arm or neck muscles, touching people or things, and obscene gesturing. At some point in the continuum of complex motor tics, the erm “compulsion” seems appropriate for capturing the organized, ritualistic character of the actions. The need to do and then redo or undo the same action a certain number of times (e. g. , to stretch out an arm ten times Definitions of Tic Disorders Tics are involuntary, rapid, repetitive, and stereotyped movements of individual muscle groups.
They are more easily recognized than precisely defined. Disorders involving tics generally are divided into categories according to age of onset, duration of symptoms, and the presence of vocal or phonic tics in addition to motor tics. Transient tic disorders ften begin during the early school years and can occur in up to 15% of all children. Common tics include eye blinking, nose puckering, grimacing, and squinting. Transient vocalizations are less common and include various throat sounds, humming, or other noises.
Childhood tics may be bizarre, such as licking the palm or poking and pinching the genitals. Transient tics last only weeks or a few months and usually are not associated with specific behavioral or school problems. They are especially noticeable with heightened excitement or fatigue. As with all tic syndromes, boys are three to four times more often fflicted than g! irls. While transient tics by definition do not persist for more than a year, it is not uncommon for a child to have series of transient tics over the course of several years.
Chronic tic disorders are differentiated from those that are transient not only by their duration over many years, but by their relatively unchanging character. While transient tics come and go – with sniffing replaced by forehead furrowing or finger snapping, chronic tics – such as contorting one side of the face or blinking – may persist unchanged for years. Chronic multiple tics suggest that an individual has several chronic otor tics. It is often not an easy task to draw the lines between transient tics, chronic tics, and chronic multiple tics.
Tourette Syndrome (TS), first described by Gilles de la Tourette, can be the most debilitating tic disorder, and is characterized by multiform, frequently changing motor and phonic tics. The prevailing diagnostic criteria include onset before the age of 21; recurrent, involuntary, rapid, purposeless motor movements affecting multiple muscle groups; one or more vocal tics; variations in the intensity of the symptoms over weeks to months (waxing and waning); and a duration of more than one year. While the criteria appear basically valid, they are not absolute.
First, there have been rare cases of TS which have emerged later than age 21. Second, the concept of “involuntary” may be hard to define operationally, since some patients experience their tics as having a volitional component – a capitulation to an internal urge for motor discharge accompanied by psychological tension aefore writing, to even up, or to stand up and push a chair into “just the right position”) is compulsive in duality and accompanied by considerable internal discomfort.
Complex motor tics may greatly impair school work, e. g. hen a child must stab at a workbook with a pencil or must go over the same letter so many times that the paper is worn thin. Self-destructive behaviors, such as head banging, eye poking, and lip biting, also may occur. Vocal tics extend over a similar spectrum of complexity and disruption as motor tics ( The most socially distressing complex vocal symptom is coprolalia, the explosive utterance of foul or “dirty” words or more elaborate sexual and aggressive statements. While coprolalia occurs in only a minority of TS patients (from 5-40%, depending on the clinical series), it remains the most well known ymptom of TS.
It should be emphasized that a diagnosis of TS does not require that coprolalia is present. Some TS patients may have a tendency to imitate what they have just seen (echopraxia), heard (echolalia), or said (palilalia). For example, the patient may feel an impulse to imitate another’s body movements, to speak with an odd inflection, or to accent a syllable just the way it has been pronounced by another person. Such modeling or repetition may lead to the onset of new specific symptoms that will wax and wane in the same way as other TS symptoms.