Reading disorders: causes, symptoms, diagnosis, treatment

Reading is a complex process that includes motor, perceptual, cognitive and linguistic aspects. Reading is impossible without the ability to distinguish lexical images (letters) and transform them into phonetic (sound) images, to grasp the syntactic structure of phrases and sentences, to recognize the semantic meaning of words and sentences, and without adequate short-term memory. A reading disorder may be part of a more general speech disorder or a more specific disorder that is not accompanied by any other speech disorders. There is a close connection between reading skills, solving mathematical problems and the state of oral speech. Children with reading disorders often have articulation disorders and vice versa. Children who are unable to read also have difficulties in constructing a conversation.

The defect inherent in reading disorders can affect a person's entire life. Difficulties in reading persist even in adulthood (especially in men). As adults, people with reading disorders still read and pronounce more slowly than their peers, and they are less likely to receive higher education. However, with early recognition and training in special educational programs, the defect can be compensated for. A surprising number of artists, famous craftsmen, and even writers (for example, Hans Christian Andersen and Postav Flaubert) suffered from reading disorders.

Pathogenesis of reading disorders

Disruption of neurophysiological processes. According to modern concepts, reading disorder is associated with underdevelopment of basic language abilities, and not with disturbances of perception and cognitive functions. Learning to read is possible due to the formation of two systems: firstly, lexical (system of visual images) and, secondly, phonological (system of auditory images) for unfamiliar words. Children with reading disorder have difficulty switching from one system to another. As a result, there is a disconnection between reading itself and understanding the meaning of what is read. With reading disorder, there are three possible variants of disruption of neurophysiological processes.

1. The ability to decode information is impaired, but understanding remains intact.
2. Decoding is intact, but comprehension is impaired (hyperlexia).
3. Both decoding and comprehension suffer.

Most students with reading disorders have impaired rapid automatic decoding, although silent reading may be more intact than reading aloud. Because spoken language relies on word recognition, it is also often impaired. Visual evoked potential studies indicate abnormal perceptual processes in patients with reading disorders, such as the inability of the visual circuits to provide adequate temporal resolution. The magnocellular system, which includes the retina, lateral geniculate bodies, and primary visual cortex, is thought to process visual information too slowly, so words may blur, blend, or “jump” off the page. The eyes may “leave” the line, leading to skipped words, making it difficult to understand the text and requiring rereading. Visual perceptual impairments may also make it difficult to communicate with others, forcing the person to rely on context, repetition, and facial expressions to understand what is happening.

Genetics

Studies show a significant accumulation of cases of reading disorders in individual families and a high level of concordance in identical twins. Although a monogenic inheritance model with modification under the influence of environmental factors has been proposed for reading disorders, they most likely represent a genetically heterogeneous condition.

Neuroanatomical data

Reading disorders may be associated with developmental abnormalities in certain parts of the brain and disruption of hemispheric asymmetry. Some patients were found to have a lack of normal asymmetry in the upper surface of the temporal lobe (planum temporale), which may disrupt the development of writing and oral speech skills. This finding was confirmed by MRI, which revealed a lack of normal asymmetry in this area. A similar lack of normal asymmetry was noted in the posterior parts of the brain. Other studies have found a link between the phonological aspects of reading disorders and congenital anomalies of the corpus callosum. Functional neuroimaging techniques also provide important information about the pathogenesis of reading disorders in children. For example, they reveal lower-than-normal activation of the frontal lobes when performing tests that require significant concentration. PET revealed changes in perfusion in the left temporoparietal region in boys with reading disorders.

Some patients have small cortical malformations, such as multiple glial scars in the cortex surrounding the Sylvian fissure, ectopic neurons, which probably reflects a disruption in the migration of cortical neurons. These anomalies can occur in the intrauterine or early postnatal periods.

Diagnostic criteria for reading disorder

• A. Reading ability (as determined by individual testing using standardized tests of reading accuracy and comprehension) is significantly lower than would be expected based on the individual's age, reported intelligence, and age-appropriate education.

• B. The disorder listed in Criterion A significantly interferes with academic performance or behavioral functioning that requires reading skills.
• B. In case of impairment of the function of the sense organs, the reading difficulties must exceed the level that can be associated with these impairments.

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Treatment of reading disorders

Non-drug treatment

Treatment of reading disorders is based mainly on the use of non-drug methods. All types of reading disorders require a strictly individual special educational program based on the assessment of the patient's neuropsychological profile, his strengths and weaknesses. The methods used allow the use of preserved cognitive functions and conceptual thinking capabilities through various sensory modalities. It is important to take into account that reading disorders are often accompanied by more systemic speech disorders. Special corrective methods, reading aloud, and the development of written speech are used. Various methods for developing reading skills have been developed, but none of them has clear advantages over others.

One of the most commonly used treatment methods is the synthetic alphabet multisensory approach called the Orton-Gillingham method. The student develops associative connections between letters and sounds, involving the auditory, visual, motor aspects of oral and written language. Once the skills of reading and writing basic words are developed, attempts are made to construct sentences from them. Reading and writing are taught in parallel with the expansion of speech practice - in order to "link" weaker skills to stronger ones. Expressive language and learning skills are also developed. The use of a new microcomputer program has brought promising results in children with speech disorders, improving word recognition and decoding skills.

The school environment can significantly alleviate the difficulties associated with this pathology. First, the degree of intervention required should be clarified. Depending on the severity of the disorder, the student may study in a regular class (with some individual work), need daily individual lessons, classes in a special class, or must attend a special school for children with learning disabilities. If the child studies in a regular class, it is necessary to allocate additional time for written assignments, correct pronunciation errors (without attracting the attention of classmates), provide the opportunity to take oral exams, if necessary, exempt from foreign language training. It is necessary to develop compensatory skills (for example, the ability to use computer programs), talents, hobbies, various forms of leisure - in order to raise self-esteem and bring the child closer to peers. It is important to help teenagers plan vacations, develop their independence skills.

The school should protect the student from negative labels and insults. Teachers and parents should recognize the signs of secondary depression, anxiety, and feelings of inferiority in a timely manner, which require individual, group, or family psychotherapy. Inability to organize one's activities, low self-esteem, emotional lability, and poor communication skills, which are typical of patients with learning disabilities, require special correction. It is important to consider that within the family, a patient with a learning disability may suffer from competition with more successful siblings or from ridicule by younger siblings.

Many parents who are frustrated, anxious, or guilty need support from a doctor and psychological help. The doctor should take on the responsibilities of an advocate for the sick child in his or her relationship with the school system. At an older age, special programs in the higher education system can be used. The activities of public groups that unite parents and defend the interests of patients are useful. A number of publications reflect the legal aspects associated with these disorders.

Nootropics are a separate pharmacological class that includes agents that enhance cognitive functions. Nootropics can be useful in the treatment of cognitive disorders, including learning and attention disorders, syndromes associated with organic brain damage, and mental retardation. However, it should be noted that proponents of nootropics often make overly optimistic statements about the effectiveness of these drugs. In this regard, the doctor should strive to protect the patient and his family from scientifically unsubstantiated recommendations. One of the drugs that may have some therapeutic effect is piracetam. Studies have been conducted on various piracetam analogues, such as primeracetam, but no clear evidence of their effectiveness has been obtained, and none of them are approved for use in humans. Some drugs used in adults to treat memory disorders (for example, hydergine) have not had any significant effect on cognitive functions in children. There is currently no evidence that any special diet, high doses of vitamins (megavitamins), micronutrients, or separate meals are effective in treating learning disorders or enhancing cognitive function.

Pharmacotherapy of comorbid disorders

It is important to treat not only primary learning disorders but also comorbid disorders. Although psychostimulants have shown short-term improvement in children with reading disorder and attention deficit hyperactivity disorder, they have been ineffective in treating isolated reading disorder. However, psychostimulants have been shown to improve writing in children with learning disorder and comorbid attention deficit hyperactivity disorder. Anxiolytics have been used in comorbid anxiety disorder or secondary anxiety caused by learning disorder, but they have not shown significant improvement.

Piracetam. Piracetam - 2-oxo-1-pyrrolidineacetamide - is used to influence the primary defect underlying the reading disorder. Although the drug was initially created as a GABA analogue and intended to treat motion sickness, it cannot be classified as a GABA receptor agonist or antagonist. It has been shown that piracetam can reduce the level of acetylcholine in the hippocampus, change the content of norepinephrine in the brain, and directly affect metabolic processes, leading to an increase in ATP content. But whether these effects are related to the therapeutic action of the drug remains unclear. Piracetam prevents the development of post-hypoxic amnesia. Thus, its effect on memory may be associated with increased tissue oxygen supply. There is also evidence indicating that piracetam can facilitate the exchange of information between the cerebral hemispheres through the corpus callosum. A study of the effect of piracetam in adults with reading disorder showed that it improves verbal learning. As shown by the study of visual evoked potentials, piracetam facilitates the processing of visual speech stimuli in the left parietal cortex. According to the data of a multicenter study lasting 1 year, piracetam in patients with reading disorders improved the state of verbal cognitive functions (which was confirmed not only by neuropsychological, but also by neurophysiological methods - by analyzing event-related potentials), but did not have a significant effect on non-verbal cognitive functions. Another study, which included 257 boys with reading disorders, showed that piracetam increases reading speed, but does not affect reading accuracy or reading comprehension. However, in another, longer multicenter study, piracetam led to some improvement in reading aloud, although it did not affect the speed of reading and information processing, speech and mnemonic processes. A European study demonstrated that piracetam is able to correct a learning defect associated with the "kindling" mechanism. Piracetam is a safe drug that does not cause serious side effects.

Thus, the use of piracetam opens up some prospects in the treatment of reading disorders, especially in terms of improving the identification of words and syllables. However, at present, the drug cannot be recommended as the only treatment for reading disorders. Further studies are needed to evaluate the effectiveness of piracetam as monotherapy or in combination with speech therapy. Additional studies are needed to examine the effect of piracetam on the speed of processing visual and auditory information. There is currently no data on the effect of piracetam on concomitant syndromes in patients with reading disorders. Piracetam is approved for use in Europe, Mexico, Canada, but not in the USA.