Varieties of Comorbid Disorders in Children with Mental Retardation

Bochkina Elena Valeryevna ORCID: 0000-0003-1099-0047 Lecturer Moscow Financial-Industrial University "Synergy" 143530, Russia, Moscow region, Dedovsk, Voykova str., 14 bochkina.elena@gmail.com Other publications by this author     Doronicheva Mariya Mikhailovna Neurologist, Pediatric Psychoneurology Research Center 74 Michurinsky Ave., Moscow, 119602, Russia maridoro@mail.ru Shatilova Nadezhda Nikolaevna PhD in Medicine Neurologist, Pediatric Psychoneurology Research Center 74 Michurinsky Ave., Moscow, 119602, Russia shatilovaN@mail.ru

Plokhikh Dmitrii Aleksandrovich PhD in Medicine Deputy Chief Physician for Educational and Methodological Affairs, Kuzbass Regional Children's Clinical Hospital named after Yu. 650029, Russia, Kemerovo, Voroshilova str., 22a d.plokhikh@rambler.ru

IntroductionEvery year there is an increasing number of children with impaired speech development.

According to WHO, in the 2000s, every 6-1 child had a delay in speech development, now the data show that these developmental disorders are inherent in every 3rd child of preschool age. By school age, this indicator stands at 25% in Russia and 19% abroad ^{[11, p. 170]}. It is worth noting that the group of children with speech disorders includes not only those children with general speech underdevelopment, but also children with delayed speech development, autism spectrum disorder and children with combined diagnoses, one of the manifestations of which is delayed speech development.

There are several generally accepted definitions for the term ZPR – foreign and domestic. In Australia and the USA, the ZPR is interpreted as ""auditory processing disorder"" ^{[10, p. 34]}. This definition is based on 44 different conditions identified in 2017, which manifest themselves in violation of the processing of audio stimuli by the cerebral cortex with absolutely preserved hearing. 

In the national science in 1959, G.E. Sukhareva proposed a definition of the concept of mental retardation (hereinafter referred to as PSR). By ZPR, the author understood mental retardation, in which the main higher mental functions (memory, thinking, imagination, attention, perception) are not so well developed compared to peers.  The diagnosis of ZPR is made to a child in preschool and primary school age, if the signs of this diagnosis persist after 10 years, then the child is diagnosed with oligophrenia or infantilism.

This definition was widely used in psychological, pedagogical and psychiatric literature until 1990. After 1997, it was expanded and supplemented with new diagnoses according to ICD - 10. These diagnoses included:

1. delayed speech development;

2. dyslexia;

3. dyscalculia;

4. alalia;

5. dysgraphy;

6. behavioral spectrum disorders (more recently, this includes ADHD);

7. enuresis;

8. encopresis;

9. speech disorders of various types;

10. ticks;

11. phobias;

12. unspecified, borderline diagnoses.

This clinical diversity of children with ZPR is due to the fact that the damage to the nervous system is in different localization. Most of the clinical disorders can be correlated with the structural and functional model of the brain, which was developed by A.R. Luria. In this model, three structural and functional blocks of the brain were identified: "a) an energy block, b) a block for receiving, processing and storing extraceptive information, c) a block for programming, regulation and control of complex forms of activity" ^{[9, p. 182]}. The first block (energy) provides an optimal level of mental activity and a balance between the processes of arousal and inhibition. This block is located — from the brain stem to the mediobasal parts to the temporal and frontal lobes of the brain. Most children with ADHD have disorders and lesions in these areas. 

The second structural and functional unit is responsible for the main analyzer systems - skin–kinesthetic, auditory and visual. It is located "in the occipital and parietal regions, covering the associative zone and its overlaps (TRO)" ^{[9, p. 183]}. Due to the properly organized functioning of these areas, the memory and attention block is provided with information that the brain has previously perceived, processed and appropriated. Also, this unit is responsible for the implementation of optical-spatial activity and the arbitrariness of movements.  That is why the majority of children with ZPR have violations in spatial-temporal orientation and pronounced stereotypical voluntary motor actions.

The role of the third block is to organize the structural regulation and organization of the child's mental activity. This block is located in the frontal lobes of the brain. A.R. Luria noted that the work of the structures of this block is responsible for the proper functioning of such mental functions as forecasting (or building an anticipatory image according to E.V. Bochkina and I.B. Shiyan), goal setting, arbitrary attention, higher mental emotions, arbitrary memorization, mental and speech processes.

All components of the structural and functional blocks of the brain are represented in it symmetrically in both hemispheres (right and left). The coordinated work of all three blocks in the two hemispheres of the brain is capable of ensuring full-fledged integrative activity of the brain and mutual enrichment of all its departments and functional systems. If any department is damaged, then this can lead to a violation in one of the three blocks. In which of the blocks the lesion is located can be judged by the peculiarities of clinical and behavioral manifestations.

Attempts to systematize behavioral manifestations in children diagnosed with ZPR have been made repeatedly, but there is no generally accepted classification to date.

This is due to the fact that these disorders are at the junction of many diseases and developmental disorders that occur in pediatric and neuropsychiatric practice. Speech is a key mental function in the process of emotional-volitional, behavioral, social and intellectual development of a child. The influence of speech development on the intellectual development of a preschool child has been studied by a number of domestic and foreign scientists (a number of domestic and foreign scientists have studied intellectual development (E.V. Bochkina, L.S. Vygotsky, B.V. Zeigarnik, K. Levin, J. Piaget, etc.). They noted that with the help of speech, a child can display images of the surrounding world formed in his psyche. J. Piaget wrote that speech has the function of expressing thoughts and emotions, the better it is developed, the faster his socialization and intellectual development takes place ^{[12, p. 301]}. Figure 1 shows a diagram of the social development of speech in preschool children.

Fig.1 Socio-speech development of a preschool child

In children with ASD, this path of social and speech development is distorted, because they hardly perceive the symbolic culture of the surrounding world and do not assign socially accepted norms of behavior and communication, and also experience difficulties in the process of spatial and temporal orientation in the surrounding world.

In the works of B.V. Zeigarnik and K. Levin, it was noted that children suffering from speech or mental disorders have difficulties in the process of perception and orientation in the surrounding world ^[4;7]. L.S. Vygotsky noted that "a child with speech disorders also has disorders in mental development has difficulties in the process of perceiving sign-symbolic culture of the surrounding world" ^{[3, p. 210]}. E.V. Bochkina writes that "thanks to these images, the child shows us his level of actual mental development" ^{[2, p.121]}. When speech development is impaired, these images are impoverished and often not coherent, and "spatial-temporal representations are not formed or are not fully formed" ^{[1, p. 95]}, notes E.V. Bochkina.

N.S. Zhukova and K.S. Lebedinskaya identified the features of mental development in children with moderate and severe speech disorders. They attributed these features to:

· spatial-temporal representations are violated, concepts for spatial orientation are difficult to differentiate;

· low level of attention development, it is not stable;

· broken images created in the imagination;

· there are "stamped" actions in mental activity;

· they get tired quickly and slowly get involved in the work;

· the level of verbal memory development is reduced;

· auditory perception is reduced.

V.N. Zinovieva noted that "violations of speech development, as a primary defect, negatively affect the initially preserved intelligence" ^{[5, p.114]}. That is why violations in speech development entail violations in the mental development of the child. This type of disorders can include – a delay in intellectual development, a delay in the process of socialization and communication with peers and the occurrence of comorbid disorders.

Behavioral or comorbid disorders are commonly understood as "stable changes in behavioral images that do not correspond to the norms of behavior accepted in society" ^{[6, p. 87]}. These behavioral disorders became the subject of our study.

It should be noted that behavioral disorders in children with ASD were not a subject for independent research, because there was no complete classification of these manifestations. All available data in the psychological, pedagogical and psychiatric literature were reduced to 3-6 disparate behavioral manifestations, which did not always correspond to what the children demonstrated in the process of primary diagnosis. Recently, neurologists and psychiatrists, as well as specialists in psychological and pedagogical profile, have noted additional behavioral manifestations in children with ASD, which were not previously noted or were identified only in children with autism spectrum disorder or oligophrenia. This means that the clinical picture of these manifestations has expanded and requires significant improvement in accordance with the newly appeared data.

The theoretical analysis made it possible to identify a contradiction between the existing psychological, pedagogical and psychiatric needs in diagnostic lists that combine the most typical behavioral manifestations of children with ASD and their absence in specialists working with this category of children. Previously, there have already been attempts to systematize these behavioral manifestations, but there is no generally accepted classification today. Difficulties in the process of developing this list were caused by the fact that there is a clinical variety of manifestations of mental retardation, combined with delayed speech development and other neuropsychiatric diseases, such as autism spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD) and other unspecified diagnoses. These diagnoses have similar behavioral manifestations, but differ in the frequency of their manifestation.

The objectives of our study were to identify behavioral features in children with delayed speech development (RR) and to compile a diagnostic list (quick diagnostic card) for a quick and high-quality primary diagnosis of a child with speech problems.

Research methods: retrospective analysis of clinical data and a survey.

These research methods were chosen in order to make the most complete collection of data obtained over several years of diagnostic work with children, because some children applied for primary diagnosis and diagnosis once and were no longer observed in a medical institution. 

Thanks to the survey, those behavioral manifestations that the child most often demonstrated at home and did not commit during the examination were revealed.

A retrospective analysis of clinical data allowed us to supplement this picture with the manifestations that the child demonstrated during the initial examination.

Research objectives:

1. conduct a retrospective analysis of medical records;

2. identify the main list of recurring behavioral disorders;

3. make a list of the most common comorbid disorders.

The methodological basis of our research was: the cultural and historical theory of L.S. Vygotsky, which describes the stages of speech and intellectual development of preschool children (normotypic children and with special needs); the concept of intellectual development of Zh. Piaget, as a theory describing the nature of intellectual development of a preschool child; structural and functional model of the brain of A.R. Luria, describing the nature of the occurrence of the disorder according to the location of the lesion of the brain.

Study participantsIn our study on the identification of behavioral features in children with speech development delay (SPD), 1,000 children aged 1.5 to 7 years from 2019 to 2022 took part.

This group of children included 370 children with normal development and 630 children with delayed speech development. These features were identified using a retrospective analysis of the maps of children who had previously received rehabilitation or counseling from specialists of a neuropsychiatric hospital and a city polyclinic. At the moment, these children are not undergoing treatment and do not receive counseling.

         During data collection and analysis, all children were divided into several groups according to diagnosis and neuropsychiatric status. In total, we identified 4 groups of children. The first group included children with delayed speech development (hereinafter SRR); the second – children with delayed psycho-speech development (hereinafter SRR); the third group included children with autism spectrum disorder (hereinafter ASD); and the fourth group consisted of children with unspecified or combined diagnosis (these are those children who have there were signs of several diagnoses at the same time, for example, ADHD (attention deficit hyperactivity disorder) and ASD). It is important to note that all children included in the cohort sample were intellectually sound. The specifics of the distribution of children into groups are shown in Figure 2.

Fig. 2 Distribution of children in the study groups

Research resultsBased on a retrospective analysis of medical records of children of early and preschool age (1.5 years – 7 years), it was revealed that most children of this age category with speech development delay have similar neuropsychiatric manifestations in behavior.

These manifestations in some children were traced more clearly, in others, they did not occur regularly. Note that normotypic children may also exhibit these neuropsychiatric manifestations in behavior, but with a much lower frequency (1-2 manifestations in behavior).

We attributed the following behavioral stereotypes to the identified neuropsychiatric manifestations:

1. Selectivity in food – a child may prefer to eat food of only one color or consistency.

 2. Lack of control over the pelvic organs after 2.5-3 years.

3. The manifestation of instability of attention after 2 years, the child can hold his attention for no more than 2 minutes.

4. The child does not have an index gesture after 1.5 years.

5. The child does not react to the addressed speech – the child does not give any signs that he has heard a parent or a specialist when he is called by name or asked to do something (this does not manifest itself once).

6. Frequent manifestations of negativism - the child reacts with aggression to the addressed speech or requests (screaming, crying, biting or fighting).

7. Frequent waking up in a dream after 3 years - the child wakes up more than 3 times a night.

8. Manifestation of features of defecation (only standing or in diapers).

9. Babbling speech or bird language after 1.5 years.

10. Minimum vocabulary (50 words) after 3 years.

11. There is a sharp rollback in development after 1.5 -2 years - the child spoke words or sentences up to 1.5 years, and then abruptly fell silent (the same clinical picture is observed with other elements of intellectual development (the index gesture disappeared, stopped recognizing a significant adult, stopped pointing at objects, etc.)).

12. Fear of loud sounds – the child covers his ears if loud music is playing next to him, a dog is barking, fireworks are launched or someone is talking a little louder than usual (not shouting).

These neuropsychiatric manifestations are reflected in the behavior of children in varying degrees of severity and combinativity in children with different diagnoses. So in children with ZPR, we noted from 3 to 5 manifestations. Most often it is selectivity in food, instability of attention and babbling speech or bird language after 1.5 years.

There were from 4 to 7 manifestations in children with ZPRR. They had the same manifestations as children with ZPR, but several new ones were added to them:

1. selectivity in food;

2. minimum vocabulary after 3 years;

3. no pointing gesture after 1.5 years;

4. lack of control over the pelvic organs after 2.5- 3 years.

In children with ASD from 6 and more. Negativism, manifestation of defecation features (only standing, in diapers, behind a curtain, etc.) and fear of loud sounds were often added to the above manifestations. Sometimes, this group of children had all 12 comorbid manifestations at once.

In children from the latter group – with combined or unspecified diagnoses, there were from 3 to 7 comorbid manifestations. Most often, the following signs could be detected in them:

1. selectivity in food;

2. minimum vocabulary after 3 years;

3. the manifestation of instability of attention;

4. a sharp rollback in development after 1.5 years;

5. fear of loud sounds.

Discussion of the results and conclusionAfter identifying comorbid manifestations in individual groups, we analyzed these indicators to identify the group most common in all the neuropsychiatric diagnoses we studied.

The most common manifestations were attributed to us:

1. Selectivity in food.

2. The manifestation of instability of attention.

3. The child does not respond to the addressed speech.

4. Babbling speech or bird language after 1.5 years.

5. Minimum vocabulary (50 words) after 3 years.

6. There is a sharp rollback in development after 1.5 -2 years.

7. Lack of control over the pelvic organs after 2.5-3 years.

These manifestations were noted in 75% of the examined children, and the first 5 of them? 87% of children of early and preschool age.

The obtained indicators give us the opportunity to compile a list of the most common comorbid disorders. This checklist can be used for screening assessment of the spectrum of comorbid disorders in a child with delayed speech development and to determine the direction of in-depth examination in connection with the prevailing behavioral pattern (ASD, delay of isolated speech, speech and cognitive development) and timely targeted correction. Belonging to a certain diagnosis can be revealed due to the number of behavioral behaviors present.

The further direction for our research will be the work with these children on the development of the perception of the sign-symbolic culture of the surrounding world, through which socially accepted norms of behavior and communication are appropriated, and the development of spatial and temporal orientation in the surrounding world. Thanks to this work, we hope for the speech and intellectual development of this group of children, as well as the correction of these behavioral stereotypes by correcting their social communication and interaction skills.