attention deficit hyperactivity disorder ( hyperactivity disorder) - Causes, Symptoms and Treatment .MF .

August 12, 2017 17:52 | Nerve Disease

Someone thinks that it's just a character, someone thinks of wrong education, but many doctors call it attention deficit disorder with hyperactivity.Attention Deficit Hyperactivity Disorder (ADHD) - dysfunction of the central nervous system (mainly the reticular formation of the brain), manifested by difficulties in maintaining concentration and attention, learning and memory disorders, as well as the complexities of handling exogenous and endogenous information and incentives.This is one of the most common neuropsychiatric disorders in children, its prevalence ranges from 2 to 12% (on average 3-7%) is more common in boys than in girls.ADHD can occur both in isolation and in combination with other emotional and behavioral disorders, has a negative impact on learning and social adaptation of the child.

first manifestations of ADHD are usually marked with 3-4 years of age.But when the child gets older and goes to school, it raises additional difficulties since the beginning of the school makes new and hi

gher demands on the child's personality and his intellectual capacities.It was during his school years become apparent violation of attention, and difficulty mastering the curriculum and poor academic performance, self-doubt and low self-esteem.

Children with attention deficit syndrome have normal or high intelligence, but tend to fail at school.In addition to learning difficulties, attention deficit hyperactivity disorder manifested motor, the defect concentration, distractibility, impulsive behavior, problems in relationships with others.Apart from the fact that children with ADHD behave badly and poorly in school, getting older, they may be at risk for the formation of deviant and antisocial behavior, alcoholism, drug addiction.Therefore, it is important to recognize the early symptoms of ADHD and to know about the possibilities of their treatment.It should be noted that there is attention deficit disorder in both children and adults.

Causes ADHD

Authentic and the only reason the syndrome has not yet been found.It is believed that forming the basis of ADHD are neurobiological factors and genetic mechanisms organic early damage of the central nervous system, which can be combined with each other.They determine the changes in the central nervous system, disorders of higher mental functions and behaviors of ADHD appropriate picture.The results of modern studies indicate involvement in the pathogenetic mechanisms of ADHD system "associative cortex, basal ganglia, thalamus, cerebellum, prefrontal cortex," in which the coordinated functioning of all the structures provides a focus control and organization behavior.

In many cases, an additional effect on children with ADHD have a negative social and psychological factors (first of all - within the family), which by themselves do not cause the development of ADHD, but always contribute to strengthening observed in the child's symptoms and adaptation difficulties.

genetic mechanisms. Among the genes that determine predisposition to ADHD (of which some role in the pathogenesis of ADHD was confirmed, while others are considered as candidate) include genes that regulate the exchange of neurotransmitters in the brain, particularly noradrenaline and dopamine.Dysfunction of neurotransmitter systems in the brain plays an important role in the pathogenesis of ADHD.Thus the basic importance disorders of synaptic transmission processes that entail separation, break links between the frontal lobes and subcortical structures, and as a consequence - the development of ADHD symptoms.In favor of violations neurotransmitter transmission systems as the primary link to ADHD development suggests that the mechanisms of action of drugs, the most effective in the treatment of ADHD, are to activate the release and inhibition of the reuptake of dopamine and norepinephrine in the presynaptic nerve terminals, thus increasing the bioavailability of neurotransmitters at the synapse level.

considered as a result of disorders of attention zadnemozgovoy system regulated by noradrenaline, while the characteristic of ADHD disorder behavioral inhibition and self-control in modern conceptions of attention deficits in children with ADHD - a lack of dopaminergic control of the pulse entering the system to perednemozgovoy attention.In zadnemozgovuyu system includes superior parietal cortex, superior colliculus, thalamus cushion (dominant role in this belongs to the right hemisphere);this system receives a dense noradrenergic innervation from the locus coeruleus (blue stain).Norepinephrine inhibits spontaneous discharges of neurons, thereby zadnemozgovaya attention system, which is responsible for the orientation for new incentives, is prepared to work with them.Following this, it switches to the mechanisms of attention perednemozgovuyu control system, which includes the prefrontal cortex and the anterior cingulate.The susceptibility of these structures with respect to the incoming signal is modulated by dopaminergic innervation from the ventral midbrain nuclei tires.Dopamine selectively regulates and restricts excitatory impulses to the prefrontal cortex and the cingulate gyrus, providing a reduction in excessive neuronal activity.

attention deficit hyperactivity disorder is considered to be polygenic disorder, in which at the same time there are numerous violations of the metabolic processes of dopamine and / or norepinephrine due to the influence of several genes, overlapping protective action of compensatory mechanisms.The effects of the genes that cause ADHD, are complementary.Thus, ADHD polygenic pathology seen as complex and variable with inheritance, and at the same time as a genetically heterogeneous state.

Pre- and perinatal factors play an important role in the pathogenesis of ADHD.The formation of ADHD may precede disorders of pregnancy and childbirth, particularly gestosis, eclampsia, first on account of pregnancy, maternal age younger than 20 or older than 40 years, long duration of labor, prolonged pregnancy and prematurity, low birth weight, morphofunctional immaturity, hypoxic-ishemicheskaya encephalopathy, a disease of the child in the first year of life.Other risk factors include the use of the mother during pregnancy, certain drugs, alcohol and smoking.

Apparently, with early brain injuries due detected in children with ADHD compared with healthy peers using magnetic resonance imaging (MRI), a decrease in prefrontal areas of the brain sizes (mainly in the right hemisphere), the subcortical structures of the corpus callosum, cerebellar.These data support the concept that, the occurrence of ADHD symptoms due to impaired connections between prefrontal and subcortical nodes, especially the caudate nucleus.In the future, additional confirmation through the use of functional neuroimaging techniques have been obtained.Thus, the determination of cerebral blood flow by single photon emission computed tomography in children with ADHD compared with healthy peers decreased blood flow has been demonstrated (and hence the metabolism) in frontal lobes, subcortical nuclei and midbrain, and the greatest changes were expressed atcaudate nucleus.According to the researchers, changes in the caudate nucleus in children with ADHD were the result of his hypoxic-ischemic injury in the neonatal period.Having a close relationship with the thalamus, caudate nucleus plays an important modulation of function (mostly inhibitory character) polysensor impulses, and the lack of inhibition polysensor impulses can be one of the pathogenic mechanisms of ADHD.

Using positron emission tomography (PET) it was found that the transferred birth brain ischemia involves persistent changes in dopamine receptors of the 2nd and 3rd types of striatal structures.As a result of reduced ability to bind dopamine receptors and formed functional failure of the dopaminergic system.

recent comparative MRI study of children with ADHD, the aim of which was to assess regional differences in the thickness of the cerebral cortex and comparing their age dynamics with clinical outcomes showed that in children with ADHD revealed a global reduction in the thickness of the cortex, the most pronounced in the prefrontal (medial and upper) and precentral departments.Thus in patients with worse clinical outcomes in the primary survey found most small thickness of the cortex in the left medial prefrontal area.Normalization of the thickness of the right parietal cortex was accompanied by the best outcomes for patients with ADHD and may reflect a compensatory mechanism associated with changes in the thickness of the cerebral cortex.

Neuropsychological mechanisms of ADHD are considered from the standpoint of violations (immaturity) functions of the frontal lobes of the brain, primarily - the prefrontal area.Manifestations of ADHD are analyzed from the point of deficiency functions of the frontal and prefrontal regions of the brain and the lack of formation of the control functions (UV).Patients with ADHD exhibit "control dysfunction."Development of UV and maturation of the prefrontal area of ​​the brain is a long process, continuing not only in childhood but also in adolescence.UV - quite a broad concept, referring to the range of skills that are necessary task of maintaining consistency in efforts to solve the problem, aimed at achieving a future goal.Significant components of UV who suffer with ADHD are: impulse control, behavioral inhibition (suppression);organization, planning, management of mental processes;maintaining attention, retention of distractions;inner speech;working (RAM) memory;foresight, forecasting, look to the future;retrospective evaluation of past events, the mistakes;change, flexibility, the ability to switch and revision of plans;choice of priorities, the ability to manage time;separation of emotion from the real facts.Some researchers have focused on UV "hot" social aspect of self-regulation and the possibility to control their child's behavior in the community, while others emphasize the role of regulation of mental processes - "cold" cognitive aspect of self-regulation.

Influence of environmental factors. Anthropogenic pollution of the human environment, largely due to the group of trace elements of heavy metal, can have negative consequences for children's health.It is known that in proximity to many industrial zones are formed with a high content of lead, arsenic, mercury, cadmium, nickel, and other trace elements.The most common neurotoxicants from the group of heavy metal is lead, and the sources of pollution of their environment - industrial emissions and vehicle exhaust gases.lead intake of children can cause cognitive and behavioral disorders in children.

role of dietary factors and unhealthy diet. emergence or strengthening symptoms of ADHD can contribute to imbalance power (e.g., lack proteins by increasing the amount of easily digestible carbohydrates, especially in the morning), and the insufficiency of dietary micronutrients including vitamins folate, omega-3 polyunsaturated fatty acids (PUFAs), macro- and microelements.Micronutrients such as magnesium, pyridoxine and some other direct effect on the synthesis and degradation of the monoamine neurotransmitter.Therefore, micronutrient deficiency can affect neurotransmitter balance, and hence the manifestation of symptoms of ADHD.Of particular interest among
micronutrients attracts magnesium, which is the natural antagonist of lead and facilitates rapid elimination of the toxic element.Therefore, magnesium deficiency, among other effects may contribute to the accumulation of lead in the body.

Magnesium deficiency in ADHD may be associated not only with its insufficient intake in the diet, but also with the increased demand for it in the critical periods of growth and development, with severe physical and neuropsychiatric loads, impact stress.In terms of environmental load as propellants are the metals magnesium and nickel cadmium together with lead.In addition to lack of magnesium in the body to manifest symptoms of ADHD can be influenced by deficiencies of zinc, iodine and iron.

Thus, ADHD - a complex neuropsychiatric disorder with structural, metabolic, neurochemical, neurophysiological changes in the central nervous system, as well as neuropsychological disorders of the information processing and UV.

symptoms of ADHD in children

Symptoms of ADHD in a child can be a cause for the primary treatment for pediatricians, speech therapists, speech pathologists, psychologists.Often the symptoms of ADHD for the first time pay attention to teachers of preschool and school educational institutions, and not the parents.Detection of these symptoms - an occasion to show the child neurologist and neuropsychologist.

main symptoms of ADHD

1. Violations attention
not keeping attention to detail, make many mistakes.
with difficulty retains attention in the performance of the school and other jobs.
not listening speech addressed to him.
can not adhere to the regulations and to pursue the case.
not able to independently plan, organize the performance of tasks.Avoid
cases requiring long-term mental stress.
Often loses things.
Easily distracted.
Shows forgetfulness.
2a. Hyperactivity
often make restless movements with his hands and feet, fidgeting in place.
can not sit still when it is needed.
Often runs or climbs somewhere when it is inappropriate.
can not quiet, calm play.
excessive purposeless motor activity has proof character, it does not affect terms and conditions of the situation.
2b.Impulsiveness
answer questions, without listening to the end and did not hesitate.
can not wait for their turn.
disturb others, interrupting them.
talkative, unrestrained in speech.

mandatory characteristics of ADHD are:

- Duration: symptoms observed for at least 6 months;
- persistence, spread to all spheres of life: adjustment disorder observed in two or more types of environmental conditions;
- the severity of violations: Substantial disturbances in learning, social contacts, professional activity;
- excludes other mental disorders: symptoms may not be associated exclusively with the passage of another disease.

Depending on the prevailing symptoms allocate 3 forms of ADHD:
- Combined (combined) form - there are three groups of symptoms (50-75%);
- ADHD with primary attention disorders (20-30%);
- ADHD with predominance of hyperactivity and impulsivity (about 15%).

Symptoms of ADHD have their own characteristics in pre-school, primary school and adolescence.

preschool age. At the age of 3 to 7 years old usually begin to show hyperactivity and impulsivity.Hyperactivity is characterized by the fact that the child is in constant motion, can not bear to sit still in the classroom for even a short time, too talkative, and sets an infinite number of questions.Impulsivity is reflected in the fact that he acts without thinking, can not wait for their turn, does not feel the restrictions in interpersonal communication, intervening in conversations and frequently interrupting others.Such children are often described as not able to behave or too temperamental.They are extremely impatient, argue, make noise, shout, which often leads to outbreaks of severe irritation.Impulsivity may be accompanied by recklessness, resulting in the child endangers himself (increased risk of injury) or others.During the game the energy brims over, so the games themselves become destructive.Children sloppy, often abandoned, break things or toys, naughty, bad subject to the requirements of the adults can be aggressive.