Introduction to attention deficit disorder in children

Children with attention deficit disorder, hyperactive child syndrome (hyperactivechildsyndrome), is the most common neurodevelopmental disorder in childhood. The classification of Chinese mental illness is called hyperactivitydisease, also known as attentiondeficithyperactivity disorder (ADHD). ), attentiondeficience peractivity disorder (ADHD), which was previously referred to as "minimal brain dysfunction" (MBD), but according to research in the past 20 years, many children diagnosed with MBD have not Find any history or sign of brain damage. In addition, many children with brain damage have not seen hyperactivity symptoms, mainly characterized by hyperactivity and restless behavioral disorders, attention disorders, irritability, impulsiveness, restlessness, and poor academic performance. In recent years, with the research progress of modern cognitive psychology, it is believed that the core defects of the disease may exist in the process of processing or efferent (reaction) of the body, or it may be the defect of the comprehensive information ability of the body and thus the selectivity of the motion response. Poor suppression.

basic knowledge

The proportion of sickness: 0.01%

Susceptible people: children

Mode of infection: non-infectious

Complications: conduct disorder


Pediatric attention to the cause of defects

Genetic factors (10%):

In the family research survey, it was found that the disease has a family aggregation phenomenon. The children of ADHD children have ADHD in childhood, and there are more children with snoring, social morbidity and alcoholism than normal children. The prevalence of parents in the children was 20%, the prevalence of first-degree relatives was 10.9%, and the prevalence of second-degree relatives was 4.5%. The same disease rate of single-oval twins is 5l%-64%, and the twin-child twins have the same disease rate of 33%.

Neurotransmitter system (30%):

Studies have shown that this disease may be related to central neurotransmitter metabolism defects. In recent years, DA, NE and 5-HT hypotheses have been proposed. Metabolites of DA and NE in blood and urine of children are lower than normal children, suggesting 5-HT dysfunction. Other studies have found that increased dopamine beta hydroxylase activity is associated with the search for novel behaviors and actions. The increased activity of catecholamine O-methyltransferase (COMT) is associated with attention deficits and hostility.

Developmental delay (25%):

Clinical observations have found that children with ADHD often have soft coordination signs such as clumsy and meticulous movements, and the soft signs of the nervous system such as visual and auditory difficulties. And often accompanied by open speech late, delayed language development, abnormal speech function stuttering, functional enuresis or fecal matter. Many studies suggest that this may be due to a delay in the maturation of the central nervous system or due to insufficient arousal in the cerebral cortex.

Psychosocial factors (20%):

The persistence of environmental, social and family factors is the key to inducing and promoting ADHD. Including: bad social atmosphere and peer influence, family economic difficulties, housing overcrowding, family disharmony or divorce, disparate parenting, improper parenting, excessive love or indulgence, poor parental personality, maternal snoring or depression, parents have anti Factors such as social behavior or material dependence, physical or psychological abuse of children by children, lack of attention to children's needs, separation of childhood from parents, and inappropriate teacher education methods can all contribute to the occurrence and persistence of ADHD.

Other factors (10%):

Mild brain damage caused by various causes, affecting the function of the nervous system, may lead to inattention and hyperactivity search. Vitamin deficiency food allergy, food flavoring additives, elevated blood lead levels, decreased blood zinc levels, etc. may also contribute to ADHD.


The occurrence of this disease is related to the brain regulation of behavior. There is increasing evidence that the brain structure and function of individuals with this disease are different from normal individuals, using neuroimaging techniques, including positron emission tomography (PET). Functional magnetic resonance imaging (FMRI) and single-photon emission computed tomography (SPECT). Some studies have found that the frontal lobe (prefrontal cortex), basal ganglia and corpus callosum of the individual are different in morphology from the normal control group. The blood flow and glucose metabolism in these areas are also lower than in the normal population. Since the frontal lobe is the executive center of the brain, the center manages the processing of information through contact with other parts of the brain, and is responsible for processing the incoming information and selecting appropriate Emotional and motor responses, the researchers therefore assumed that the frontal lobe of the individual, due to changes in contact with other parts of the brain, could not function properly, and that this change in association involves the catecholamine-like neurotransmitter in the brain ( The change in the levels of dopamine and norepinephrine is based on the ability to alter the neurotransmitter of the above-mentioned neurotransmitters such as methylphenidate The disease is effective.

It is generally believed that the core problem of attention deficit hyperactivity syndrome is attention deficit. However, some studies in recent years have questioned this. In event-related potential (ERP), N2 often represents signal detection, and P3 represents signal processing, using ERP. Detection of ADHD children, found that the N2 wave amplitude is reduced, and this phenomenon improves with the age of children, which may support the attention deficit of children with this disease, but another more common finding of ERP is the reduction of P3 amplitude. And the extension of the incubation period indicates that the main problem of children with ADHD may be the information processing defect after receiving the signal. According to the information processing psychology, this defect is manifested in the abnormal output of the child after receiving the information. In other words, the child cannot choose The proper response does not inhibit the inappropriate response after receiving the information. It is the inappropriate activity of the child that makes us think that the child cannot concentrate.

At present, it is believed that the occurrence of this disease has a genetic basis. The prevalence of blood relatives is significantly higher in patients with this disease than in non-blood. The incidence of twins is extremely high, although the exact genetic pattern is still unclear, but the more More and more researchers are using molecular genetics to identify possible genes. In 1995, Cook reported that some patients with a family history of this disease had defects in the dopamine transduction gene, which proved to some extent the genetic basis of the disease. This is consistent with the aforementioned role of dopamine in the pathogenesis of this disease. In addition, the dopamine type 4 receptor (DRD4-7) is currently known to be a non-coding region containing seven repetitive series. It is a gene related to the novelty of exploring adult factors. In this disease, 30% of these children have alleles of the 7 repeat series, but only half of them in the general population, in a wide variety called thyroxine. In rare autosomal dominant diseases of the generalized resistance to thyroid hormone (GRTH), approximately 70% of children and 40% of adults present symptoms of this disease.

Although genetic factors play an important role in the etiology of this disease, environmental factors still have a very significant impact on the expression of people with so-called quality of the disease, such as poor family or school education, low socioeconomic status of parents, children Early emotional deprivation, parental personality disorder, etc., other related environmental factors such as lead poisoning, food additives, etc., but lack of consistency.


Child attention deficit prevention

1. It is necessary to promote pre-marital examination to avoid marriage of close relatives; when choosing a spouse, it is necessary to pay attention to whether the other person has mental disorders such as epilepsy and schizophrenia.

2. Age-appropriate marriage, do not marry early pregnancy, do not be too late marriage, late pregnancy to avoid congenital deficiency of the baby; planned eugenics.

3. In order to avoid the chance of birth injury and reduce brain damage, it should be naturally produced because the proportion of cesarean section in children with ADHD is higher.

4. Pregnant women should pay attention to tempering temperament, keep a good mood and peace of mind, avoid cold and heat, prevent disease and health search, use drugs to ban alcohol and tobacco, and avoid the effects of poisoning, trauma and physical factors.

5. Create a warm and harmonious living environment, so that children can spend their childhood in a relaxed and pleasant environment, and teach students in accordance with their aptitude.

6. Pay attention to reasonable nutrition so that children can develop good eating habits, not partial eclipse, not picky eaters; ensure adequate sleep time.

7. Try to avoid children playing with lead-painted paint toys, especially if they are not included in the mouth.


Pediatric attention deficit disorder complications Complications

Lack of academic performance, emotional disorders, problem behaviors and conduct disorder are mostly secondary. Children with this disease may often be criticized by teachers and parents for fighting because of the above problems. Children often lack self-confidence and self-esteem, and are prone to secondary emotional disorders. Including anxiety (about 25%) and mood disorder (20%), the incidence of various problem behaviors is also high, especially the incidence of violations can reach 50%, and those with severe behavior (30% to 50%) Early childhood manifestations of behavioral naive, defying, getting along badly with classmates, gathering with students with poor academic performance, or retreating, loneliness, then lying, stealing, leaving home is at least a year of crime.


Children with attention deficit symptoms symptoms Common symptoms Attention deficits, irritability, language development retardation, learning difficulties

1. Too many activities

The performance is obvious, the activity is increased, the excessively quiet, the back and forth often run, can't sit still in the classroom, often wriggle or stand up in the seat, excessively noisy, too many words, not disciplined, not listening to orders, the more need to keep In a quiet and disciplined environment, the more active, the more likely you are to play dangerous games.

Hyperactivity can be divided into pervasive hyperactivity and situational hyperactivity. The former has more hyperactive behaviors, regardless of the occasion, and the performance is obvious in schools and homes, while the latter is only in some occasions. (often a school) hyperactivity, while in other occasions there is no hyperactivity.

2. Inattention

One of the main manifestations of this disease is that you can't insist on listening carefully to the teacher during class. You are often distracted by the external disturbances, such as being attracted by the footsteps outside the classroom, talking sounds or car horns, or observing the blackboard. Stain on the ceiling or on the desk, you can't concentrate on doing homework, do stop-and-go, or be careless; do things can't persist, the attention of the disease mainly involves advanced forms of attention ("active attention"), ie Choose a certain purpose and direction (such as listening to the class), take the initiative to focus on this direction, and at the same time consciously avoid the stimulus that is not related to the purpose (such as the bird outside the window), the child has a defect in the direction of attention and maintenance attention. Give too much attention to irrelevant stimuli.

3. Impulsive behavior

Emotional instability, irritability, lack of self-control, self-willedness, easy to be over-excited, vulnerable to external influences, and vulnerable to setbacks, so as to quarrel with classmates.

4. Learning difficulties

Although the intelligence is normal or close to normal, it lacks the necessary attention and lacks persistence in the learning process, so the academic performance is backward.

5. Neurodevelopmental disorders

Children with persistent ADHD often have this performance, such as fine coordination and awkward movements. The lace-fastening buttons are not flexible, and it is difficult to distinguish between left and right, and fashion may be accompanied by language development retardation.


Pediatric attention deficit defect examination

Laboratory inspection

There is currently no specific laboratory test for this disease. When other conditions, such as infection, occur, laboratory tests show positive results from other conditions. The following general checks can be made:

1. Regular hematuria examination, biochemical electrolyte examination.

2. Serum immunological examination.

Film degree exam


No abnormalities were found in the CT scan of hyperactivity disorder.


The area of the corpus callosum (upper anterior motion zone) and the corpus callosum (pre-motion zone and auxiliary exercise zone) was significantly larger in the ADHD group than in the control group, and the increase in these areas was evident in the hyperkinetic-impact factor of the Conners scale. Positive correlation. It is suggested that some of the clinical features of ADHD can be expressed by differences in the number of brain morphology. On the other hand, Wise's literature review of the function of the primate frontal motion zone suggests that the premotor zone plays a key role in "inhibition of autonomic responses to some sensory stimuli." For example, the cortical damage of the anterior motor zone of the macaques does not inhibit the behavior of taking bananas through a transparent plastic tray, but still repeatedly and impulsively attempts to pass through the plastic tray. The same macaque quickly got the banana before the damage. This defect is similar to human defect inhibition and is called the ADHD core defect by Barkley.

3. Computerized EEG (CEEG)

From a group of children with dyslexia, the bilateral frontal lobe, left and left posterior areas were mainly characterized by increased alpha wave activity, suggesting that the cortical arousal was insufficient. No specific changes were observed in CEEG examination of attention deficit hyperactivity disorder and Tourette syndrome. The study found that compared with the normal children's control group, the conventional EEG abnormality rate of attention deficit hyperactivity disorder was higher, the slow wave activity increased, the fast wave decreased, and the rhythm of the occipital region and the right temporal region was significantly lower than that of the normal control children. Because of the study population, standards, electrode placement, and test conditions, interpretation of attention deficit hyperactivity disorder CEEG is very difficult. Most consistent studies suggest that the intensity is low within 8 to 10 Hz and is inconsistent with findings in normal children. In children with attention deficit hyperactivity disorder, there is almost no change in peak and latency after giving ordinary and novel stimuli, indicating that children with attention deficit hyperactivity disorder have difficulty in the correct selection and evaluation of the given stimuli.

4. Positron emission tomography (PET)

Previous studies of ADHD children and control children found that children with ADHD had decreased brain cerebral glucose metabolism, and the most different brain regions were the anterior motor area and the frontal gyrus. Some scholars believe that the therapeutic effect of psychostimulants is to improve symptoms by increasing caudate nucleus blood flow. Matochik et al (1994) hypothesized that psychostimulants with better efficacy for ADHD can increase or normalize the local glucose metabolism rate in patients with ADHD. Further, 18 adult ADHD patients were scanned with PET and 18F (deoxyglucose) was used as a tracer to measure the changes of glucose metabolism before and after stimulant treatment. The results showed that glucose metabolism was changed in only 2 brain regions in 60 brain regions of interest, the anterior side of the right caudate nucleus decreased, and the right posterior region increased. In the therapeutically effective group, the patient's glucose metabolism increased. However, whether the increase in local glucose metabolism depends on the role of stimulants remains to be further studied.

5. Single photon emission tomography (SPECT)

In the study of attention deficit hyperactivity disorder, Lou et al. (1990) found in ADHD that the amount of perfusion in the new striatum and frontal area was relatively decreased and the amount of perfusion in the primary sensory area was relatively increased. This perfusion pattern was obtained after methylphenidate treatment. Reversal, it is believed that prefrontal and neocortical dysfunction plays an important role in attention deficit hyperactivity disorder. The same research team also emphasized that the low blood flow in the striatum area indicates that the reduction of striatum activity is a feature of attention deficit hyperactivity disorder. Hamdan-Allen compared the relationship between mean cerebral blood flow and CBCL behavioral items, and found no relationship between blood flow and attack and hyperactive scores. It is believed that the prefrontal cortex plays a regulatory role in the control of impulsivity, attack and hyperactivity. The study of cerebral blood flow should also consider the association with catecholamines. Lou et al. (1990) used 133Xe inhalation to measure regional cerebral blood flow (rCBF) for multiple causes of inability to learn. In the absence of attention deficit disorder and/or speech-syntactic speech difficulties, the striatum and periventricular rCBF were low. The striatal region was most prominent, while the speech-syntactic speech difficulty was not associated with ADHD. The left forehead and left central fissures were lower than the right. Raynaud et al (1989) found that 9 children with speech-discriminatory speech had low blood flow in the left hemisphere. Studies have suggested that the left hemisphere is functionally inferior.

Amen and Paldi (1993) performed a SPECT scan of 54 children with ADHD who were eligible for DSM-III-R. Sixty-five of children with ADHD showed a decrease in prefrontal activation during cognitive activity, compared with 5% in the normal control group. 35% did not show a decrease in prefrontal activation, and 2/3 of the prefrontal cortex activity decreased significantly at rest. It is considered that SPECT scan has positive significance for the diagnosis and treatment of ADHD.

Du Yasong et al (1997) measured regional cerebral perfusion in 17 children with ADHD and 11 normal children. The results showed that the low perfusion rate was lower in children with ADHD than in normal children. The low perfusion area involved frontal, temporal, and occipital lobe. And the thalamus; semi-quantitative analysis showed that the left basal ganglia was lower than the right side, and the right anterior cingulate gyrus and temporal lobe perfusion were lower than the corresponding part on the left side, suggesting that the frontal basal ganglia loop plays an important role in the pathophysiological mechanism of ADHD. effect.

PET studies have found that children with ADHD have reduced perfusion in the premotor and prefrontal cortex, suggesting a decrease in their metabolic rate, which is related to the control of attention and movement. MRI found abnormalities in the frontal lobe and asymmetry of the bilateral caudate nucleus.

Visual brain evoked potential (VEP) test suggests that the activity-dependent potential (ERP) mutation rate of active-passive attention in children with ADHD is small, and VEP can reflect changes in attention and cognition in children with this disease.


Diagnosis and differential diagnosis of attention deficit disorder in children


The diagnosis of this disease is mainly for clinical diagnosis, comprehensive analysis of medical history, birth history, developmental history and family history, to do neurological examination, developmental examination, intelligence examination and behavioral assessment, etc. The diagnosis of this disease should meet the following criteria:

1. The onset age is less than 6 years old and the symptoms persist for more than half a year.

2. There must be too many activities and inattention. Both of them exist at the same time. Other common symptoms can help diagnose, such as impulsiveness, reckless behavior, disregarding occasions, not paying attention to social or school norms, learning difficulties and sports. Awkward, etc., but these symptoms are not necessary to diagnose this disease.

3. Exclusion criteria should exclude other behavioral disorders, mood disorders or apparent mental retardation.

School-age children with acute onset, manifested as hyperactivity, often manifested in certain organic diseases (such as encephalitis, rheumatic encephalopathy) or functional psychosis.

Differential diagnosis

1. Mental retardation: Both can be hyperactive, impulsive and inattentive. Children with mild mental retardation have mental retardation, and there are developmental delays in language perception and exercise. Although the child with this disease may have an abnormal structure of intelligence, the overall IQ is usually in the normal range.

2. Tourette (tic): Tourette is characterized by involuntary muscles or muscle groups in a certain part of the body, intermittent, rapid and repeated repetitive contraction movement, which is significantly different from this disease, but tic disorder is common with this disease. Need to pay attention to identification.

3. Child autism: Most children with autism have significant hyperactivity and are easily misdiagnosed as the disease. However, autism is characterized by language barriers, communication disorders and stereotypes. It is not difficult to ask for a detailed history. Identification.

4. Children's normal range of hyperactivity: normal children, especially children aged 3 to 6 years old, are more active, while attention is maintained for a short period of time, which is related to children's temperament. When identifying, pay attention to the temperament or personality of parents and teachers. The coordination between children's temperament and personality is common in quiet parents or teachers to affix a similar ADHD "tag" to active children, and can avoid misdiagnosis in strict accordance with the diagnostic criteria of this disease.