The main clinical forms of oligophrenia

Due to a variety of reasons, mental and mental underdevelopment (insufficiency, backwardness) of a person, which is commonly called oligophrenia, is manifested by an equally extensive and diverse set of symptoms.

To distinguish the main features of each type of abnormal intellectual and mental state in clinical psychiatry, specific forms of oligophrenia are defined and their classification is developed.

Classification of forms of oligophrenia

As is often the case with any attempt to systematize a significant amount of similar in appearance but different in etiology phenomena, it is most difficult to choose a single classification criterion, which is particularly important in medicine. Obviously, it is the lack of common views on the principles of systematization that can explain the multivariate nature of the classification of forms of oligophrenia. Although important in the emergence of new interpretations are achievements in the study of the pathogenesis of this state.

Another author of the term "oligophrenia", the German psychiatrist Emil Krepelin (1856-1926) believed that when classifying mental illnesses, it is necessary to take into account their aetiology (first of all, pathological changes in brain structures), characteristic signs and a typical clinical picture.

Attempts to classify the forms of mental retardation were many, but as a result, the criterion was the scale of the existing mental-mental underdevelopment (in a softer formulation of the defect of the intellect). Traditional forms of oligophrenia, debility, imbecility and idiocy in the International Classification of Diseases of the 2010 edition do not appear: they were decided to be removed, as these medical terms acquired derogatory connotations (they were used in everyday speech as a definition of negative attitudes toward the individual and her actions).

According to the provisions adopted by WHO and fixed in ICD-10, depending on the degree of cognitive dysfunction, oligophrenia can be mild (F70), moderate (F71), severe (F72), and deep (F73). This distinction structures the pathology in a simplified way without taking into account many distinctive characteristics that have several dozen different forms of this abnormal state.

For example, in the pathogenetic classification of mental retardation developed in the 1960s and 1970s by Professor M.S. Pevzner (one of the founders of clinical defectology), the main was the principle of the correlation of certain cerebral lesions and their clinical manifestations.

The distinguished forms of oligophrenia according to Pevsner:

• uncomplicated form of oligophrenia, in which violations in the emotional-volitional sphere of patients are of a negligible nature;
• complicated forms of oligophrenia (complications are caused by violation of neurodynamic processes of the CNS, which can lead to excessive excitability, inhibition or weakness);
• oligophrenia with speech, hearing, and motor disorders;
• oligophrenia with manifestations similar to psychopathy;
• oligophrenia with apparent underdevelopment and insufficiency of the cortex and subcortical structures of the anterior lobes of the brain (with which, in fact, most extrapyramidal disorders, intellectual and mental disorders are related).

The forms of oligophrenia according to Sukhareva differ in the etiology and characteristics of the effects of pathogenic factors. Based on long-term observations of clinical manifestations of oligophrenia in children, Professor G.Ye. Sukhareva (child psychiatrist, 1891-1981) singled out:

• oligophrenia, caused by hereditary genetic factors (Down's syndrome, microcephaly, phenylketonuria, gargoilism, etc.);
• oligophrenia associated with the impact of a number of negative factors (viruses, treponema, toxoplasma, toxins, immunological incompatibility of mother and fetus organisms, etc.) during the period of intrauterine development;
• oligophrenia, caused by postpartum factors (asphyxia, birth trauma, infectious and inflammatory diseases of the brain).

In the modernized form (since the development of Sukhareva's classification, not less than half a century has passed), the division of the intellect defect based on pathogenesis delimits hereditary or endogenous forms of oligophrenia: all syndromes associated with gene aberrations, as well as disorders affecting metabolism, hormone synthesis and enzyme production. Accordingly, the acquired (postnatal) exogenous forms of oligophrenia arising from alcoholism or drug addiction of the mother, after rubella (ruberolar oligophrenia) transferred during pregnancy, and toxoplasmic transplantation of the fetus in pregnant women, iodine deficiency, etc., are also allocated.

There are oligophrenia of mixed etiology. For example, microcephaly, which accounts for more than 9% of diagnoses of mental retardation, is endogenous-exogenous oligophrenia, since it can be both genetically conditioned (true) and secondary, arising from the effects on the fetus of ionizing radiation.

A hydrocephalus (edema of the brain) may be a consequence of intrauterine fetal damage of the cytomegalovirus, and may also develop after a brain injury of a newborn, meningitis or encephalitis.

[1], [2], [3], [4], [5], [6], [7]

Characteristics of forms of oligophrenia

Despite all terminological innovations, the characterization of forms of oligophrenia takes into account the same morphological features, etiology and clinical manifestations. And at the heart of the description of individual forms, as is customary, the basic complex of the most characteristic symptoms is used.

The mild form of oligophrenia (mental retardation in the form of debility) is diagnosed if:

• the level of mental development on the scale of "quantity of intelligence" (intelligence quotient or IQ) varies within the limits of 50-69 on the scale of Wechsler;
• speech is undeveloped and its lexical range is limited;

Fine motor skills are not developed enough, there may be problems with coordination of movements, as well as various motor disorders;

• there are craniofacial or skeletal-muscular congenital defects (abnormal growth or head size, distorted proportions of face and body, etc.);
• the ability to think abstractly is very low, obviously the predominance of objective thinking and mechanical memorization;
• evaluation, comparison and generalization (objects, phenomena, actions, etc.) cause serious difficulties;
• the range of emotions and ways of expressing them is inadequate, often emotions are expressed in the form of affects;
• suggestibility is increased, independence is lowered, self-criticism is absent, frequent manifestations of stubbornness.

With a moderate form of oligophrenia (low degree of imbecility), the IQ is 35-49 points, and the severe form of oligophrenia (pronounced imbecility) is determined at IQ at a level of 34 and lower (up to 20 points). The line between them is very conditional, with all evidence of a mental pathology. However, with a moderate form of oligophrenia, patients can formulate the simplest phrases, are able to master elementary actions, then in severe form all this is already impossible. It should be borne in mind that this degree of cognitive dysfunction (which is diagnosed in early childhood) leads to a lack of attention, as well as complete internal lack of control of behavior (including sexual) and the manifestation of emotions. Therefore imbecile patients quickly fall into a state of psychomotor agitation and can be aggressive towards others, they also have epilepsy-like seizures.

For deep oligophrenia (idiocy), IQ is less than 20; a complete lack of ability to think, to understand what others have said and to speak for themselves; extremely low emotional threshold and the absence of all kinds of sensitivity (including taste, olfactory and tactile); atony and limitation of movements by reflex gesticulation.

[8], [9], [10], [11], [12], [13]

Atypical forms of oligophrenia

Any violation of the "standard" clinical picture of mental retardation results in so-called atypical forms of oligophrenia.

According to psychiatrists, the reasons lie in the multifactorial damage of brain structures in the process of its intrauterine development, in which the combined negative impact of both internal (genetic) and external factors is not excluded. What symptom is the manifestation of this or that pathogenic influence - it is difficult to establish with absolute exactitude.

Atypical can be considered as oligophrenia with obvious hydrocephalus: in a child - against a background of hypertrophic skull form, hearing loss and strabismus - there can be a good ability for mechanical memorization.

The way "atypical dementia" manifests itself largely depends on the local factor - that is, on what structure of the brain has suffered and how critical this damage is for the functioning of individual parts of the cortex, the cerebellum and the pituitary-hypothalamic zone of the brain.

In atypical forms of oligophrenia, specialists include emotional and sensory deprivation, to which children exposed to prolonged external isolation or exposed to difficult family conditions (alcoholic families) are exposed.

Moderate forms of oligophrenia (IQ 50-60) are almost always evident during the first years of life. These people face difficulties in school, at home, in society. In many cases - after specialized training - they can lead a practically normal way of life.

[14], [15], [16], [17], [18], [19], [20]