Tic disorder

Introduction A tic disorder is a group of syndromes characterized by involuntary, repetitive, rapid motion tics and/or vocal tics at one or more sites. These include transient tic disorder, chronic exercise or vocal tic disorder, vocalization and multiple motor joint tic disorder (twitch syndrome, Tourette syndrome). It starts in children and adolescents. Most of the disease starts in school age, and it is not uncommon in preschool age. Up to 40% of those who are younger than 5 years old. Exercise tics often occur before the age of 7 years, and the vocal twitching sounds later, mostly before the age of 11.

Cause

Because the clinical symptoms of tics are aggravated when nervousness is disturbed, when emotions are relaxed, and disappeared during sleep, the influence of psychological factors is easily seen as the cause of this disease, but the real cause is not yet clear. More related to genetic factors, neurochemical factors, and social psychological factors.

Genetic

Studies have confirmed that genetic factors are associated with the occurrence of Tourette syndrome, but the genetic pattern is unclear. A family survey found that 10% to 60% of patients had a positive family history, and twin studies confirmed that the same rate of single-ovid twins (75% to 90%) was significantly higher than that of single-ovid twins (20%). The incidence of tic disorder in foster relatives is significantly lower than that of relatives.

2. Neurochemical abnormalities

There may be neurotransmitter disorders such as DA, NE, and 5-HT in tic disorder. Most scholars believe that the occurrence of Tourette syndrome is related to the excessive release of striatal dopamine or the hypersensitivity of postsynaptic dopamine D2 receptor. The dopamine hypothesis is also an important hypothesis for the etiology of Tourette syndrome. Some scholars believe that this disease is related to central noradrenergic system hyperfunction, endogenous opioid peptide, 5-HT abnormalities.

3. Brain structure or function abnormalities

The structural and functional abnormalities of the cortical-striatum-thalamic-cortex (CSTC) loop are associated with the development of tic disorder. Structural MRI studies have found that the volume of the caudate nucleus in the basal ganglia of children and adults with dysmotility is significantly reduced, and the volume of local gray matter in the left hippocampus is increased. Functional MRI studies of vocal tics revealed abnormal activation of the basal ganglia and hypothalamic regions in patients with tic disorder, and it is speculated that the occurrence of vocal tics is associated with abnormal regulation of subcortical neural circuit activity.

4. Psychological factors

The various psychological factors that children encounter in their homes, schools, and societies, or the causes of stress and anxiety in children, may induce tic symptoms or exacerbate tics.

5. Immunity factors

Studies have shown that the patient's onset is associated with an immune response to hemolytic streptococcal infection, and some patients are effective with immunosuppressive therapy.

Studies have suggested that Tourette syndrome is an organic disease. After the drug treatment in the mid-1960s achieved significant results in Tourette syndrome, biological factors were taken seriously. In the past 20 years, the study has paid more attention to the obvious gender differences and high penetrance rate of children with this disease. In patients with neuroelectrophysiology, EEG abnormalities can reach 12.50% to 66%, but their performance is non-specific, and there is no meaningful change in evoked potentials. Some studies on neuroanatomy suggest that it may be mainly due to dysfunction of the basal ganglia pathway or damage to the basal ganglia in other parts of the brain or one or several biochemical loop abnormalities. It has been reported in neuropeptides and immunization that the level of alpha2-globulin antibodies in the blood is associated with the clinical severity of tic disorder.

In addition, perinatal complications and low-weight children were significantly higher than the control group. It was also found that autoimmune reaction after -hemolytic streptococcus infection may lead to Tourette syndrome.

an examination

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Neurological examination CT examination

Diagnosis is mainly based on medical history and mental examination. Careful observation of tic symptoms and general behavior is important for diagnosis. Tic can be temporarily controlled, so it is easy to be neglected and missed, and it is easy to be misdiagnosed because of accompanying symptoms. Therefore, it is necessary to identify the main symptoms and Secondary symptoms and before and after the onset of symptoms to determine the diagnosis.

Differential diagnosis

Differential diagnosis:

1. Rheumatic chorea: The disease is usually caused by infection in children aged 5 to 15 years. It is characterized by abnormal dance-like movements and signs of rheumatic fever such as decreased muscle tone. Laboratory tests have a rapid increase in blood sedimentation. Limitation, no vocal twitching, anti-rheumatic treatment is effective.

2. Huntington chorea: The disease occurs mostly in adults, occasionally children, is autosomal dominant inheritance, mainly for progressive involuntary dance-like movements and dementia symptoms. CT examination shows atrophy of the caudate nucleus.

3. Hepatolenticular degeneration: The disease is caused by dysfunction of ketone metabolism, extrahepatic signs and mental disorders of liver damage, and the characteristics of corneal KF pigment ring and ceruloplasmin reduction are helpful for identification.

4. Myoclonus caused by epilepsy: It is a type of seizure that lasts for a short period of time, often accompanied by loss of consciousness, and EEG high-rhythm abnormal anti-epileptic drug treatment can control seizures.

5. Delayed dyskinesia: mainly seen in the sudden withdrawal of drugs or large doses during the application of antipsychotic drugs, resulting in involuntary movement disorders, history of taking antipsychotics.

6. Acute dyskinesia: Sudden involuntary tremor dystonia caused by drugs, twisting sputum or dance-like movements, the symptoms can usually disappear after stopping the drug.

7. Childhood schizophrenia: The face of the disease is similar to Tourette syndrome, but it also has characteristic symptoms of psychosis, no vocal tics.

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