Tourette's syndrome: diagnosis

Diagnostic criteria and methods for evaluating Tourette's syndrome

Transit ticks are common - about a quarter of schoolchildren. The diagnosis is established with the preservation of ticks for at least 4 weeks, but not more than 12 months. The development of chronic tics or Tourette's syndrome may be preceded by several episodes of transient tics. Chronic ticks (XT) include motor or vocal tics (but not their combination), which persist for more than 1 year. The diagnostic criteria for Tourette's syndrome require a combination of multiple motor tics and at least one vocal tic, not necessarily at the same time. For example, in a 16-year-old youngster with multiple motor tics, but without vocal tics at the time of the examination, Tourette's syndrome should be diagnosed if vocal ticks were observed at the age of 12 years. Many consider the differences between Tourette's syndrome and chronic multiple motor tics artificial, especially considering the similar nature of inheritance according to genealogical research. Symptoms of Tourette syndrome should last more than 1 year, while the duration of remission should not exceed 3 months. According to DSM-TV, the disease should appear before the age of 18, although this criterion has varied in the past. If the tics appear later than 18 years, they should be qualified as "ticks without additional clarifications".

The question of the qualification of light ticks remains unclear. The modern DSM-IV criteria for diagnosing all types of tics require that they cause "severe discomfort or significant disability". But many children with tics do not fall in the field of view of medical services. Light or moderate tics can nevertheless cause some discomfort, and their presence, even if there is no need for pharmacological suppression of tics, can influence the treatment of comorbid disorders such as OCD or DVG. In this respect, tics can serve as a useful clinical marker that deserves mention, even if by themselves do not require treatment. Classification of the severity of tics affects the results of epidemiological and family-genetic studies: in case of mild cases, the incidence of tics will be higher, and if DSM-IV criteria are used, the morbidity rate will be lower.

[1], [2], [3]

Diagnostic criteria for Touretge syndrome

• A. Presence of multiple motor tics of not less than one vocal tic in any period of the disease, but not necessarily at the same time (tick - sudden, rapid, repetitive non-rhythmical stereotypic movement or vocalization)
• B. Tics occur many times during the day (usually outbreaks) almost daily or periodically for more than 1 year, during which time the absence of tics does not exceed 3 months
• B. The disorder causes severe discomfort or significantly disrupts the life of the patient in social, occupational or other important areas
• G. Beginning - before the age of I8 years
• E. The disorder is not caused by direct physiological exposure to exogenous substances (eg, psychostimulants) or a common disease (eg, Huntington's disease or viral encephalitis)

Examination of the patient includes a thorough physical and neurological examination to exclude the disease, which could cause hyperkinesis (eg, thyrotoxicosis). Patients with Tourette's syndrome often have mild non-specific neurological symptoms ("microsymptoms"). It was reported about more frequent detection of choreiform motions in patients with tics of OCD and DVG. Psychiatric examination and neuropsychological examination are necessary to identify comorbid psychiatric disorders or low learning ability, which may be the main cause of maladaptation. The study of hyperkinesis is best done using clinical rating scales, which provide an assessment of the type, frequency and severity of each tick. An excellent example of such a scale is the Yale Global Tic Severity Rating Scale (YGTSS). Scales based on self-assessment or evaluation by parents, such as the Turette Syndrome Symptom Score (TSSL) Scale, are also used. If you ask the patient to reproduce the available ticks, it sometimes causes a ticotic storm. Since in an unusual environment, for example, in a doctor's office, tics are often weakened or lost, videotaping tics in a home environment can be an important method for studying tics, which makes it possible to evaluate the effectiveness of therapy.

[4], [5], [6], [7], [8]

Diagnostic criteria for other variants of tics

Transient ticks

• A. Bojnichnye or multiple motor or vocal tics (that is, sudden, fast, repetitive non-rhythmical stereotyped movements or vocalizations)
• B. Tiki arise a lot once a day, almost daily for at least 4 weeks, but not more than 12 consecutive months
• B. The disorder causes severe discomfort or significantly disrupts the life of the patient in social, occupational or other important areas
• G. Beginning - under the age of 18
• E. The disorder is not associated with direct physiological exposure to exogenous substances (eg, psychostimulants) or a common disease (eg, Schwington's disease or viral encephalitis)
• E. The disorder does not meet the criteria for Tourette's syndrome, chronic motor or vocal tics

Chronic motor or vocal tics

• A. Burning or multiple motor or vocal tics (that is, sudden, rapid, repetitive non-rhythmical stereotypic movements or vocalizations), but not their combination, are present during the period of the disease
• B. Tiki arise a lot of times a day (usually outbreaks) almost daily or periodically for at least 1 year, during which time the absence of tics does not exceed 3 months
• B. The disorder causes severe discomfort or significantly disrupts the life of the patient in social, occupational or other important areas
• G. Beginning - under the age of 18
• E. The disorder is not associated with direct physiological exposure to exogenous substances (eg, psychostimulants) or a common disease (eg, Gentigton's disease or viral encephalitis)
• E. The disorder does not meet the criteria for Tourette's syndrome, chronic motor or vocal tics

Ticks without additional clarification

[9], [10], [11], [12]

Differential diagnosis of Tourette's syndrome

Given the variability and diversity of the manifestations of Tourette's syndrome, it must be differentiated with a wide range of neurological and psychiatric diseases, including Sydenham's chorea, Huntington's chorea, progressive muscular dystonia, blepharospasm, neuroacanthocytosis, post-infectious encephalitis, drug dyskinesias, compulsions and stereotypes associated with autism, mental retardation , psychoses. Differential diagnosis may require paraclinical examination and a trial therapeutic intervention.

Differential diagnosis between simple tics and other hyperkinesis is carried out taking into account the duration, localization, temporal dynamics and communication by shifting. For example, typical chorea is characterized by longer muscle contractions and chaotic involvement of different muscle groups. Chorea Sidengam develops sharply, soon after a streptococcal infection and is characterized by a combination of behavioral changes and hyperkinesis. Some of these excess movements may resemble ticks. On the other hand, with Tourette's syndrome, there are described choreiform movements that arise against a background of simple and complex motor or vocal tics. A thorough examination of the anamnesis, the course of the disease, a detailed examination to identify other symptoms of rheumatism should help in differential diagnosis between Sidenham's chorea and Tourette's syndrome.

Dystonia differs from dystonic tics by the greater persistence of hyperkinesis and the absence of clonic tics. Myoclonias usually have limited localization, while ticks vary in location and occur as outbreaks. Movement of the eyeballs, such as twitching or prolonged withdrawal, are characteristic of tics and are rarely observed with other hyperkinesias. The exceptions are:

1. dystonic oculogic crises arising as a side effect of neuroleptic therapy or as a complication of lethargic encephalitis;
2. myoclonia of the eyeballs, which often accompanies the myoclonia of the soft palate;
3. opskolonus.

Idiopathic blepharospasm, when it has minor manifestations, can be difficult to distinguish from ticotic blinking or blinking, but their differential diagnosis is usually facilitated by the presence of ticks of other localization. Blepharospasm usually affects the elderly, while Tourette's syndrome usually manifests itself in children.

[13], [14], [15], [16]