Reading disorder

Reading disorder (developmental dyslexia) is a specific reading disorder characterized by numerous errors (substitutions, omissions of letters, failure to follow their sequence), combined with a slow reading rate that is not explained by the level of intelligence, problems with visual acuity or insufficient schooling.

ICD-10 code

P81.0. Specific reading disorder. 

Epidemiology

There is no precise data on prevalence, since there are no clear criteria for distinguishing between extreme variants of the norm.

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Causes of reading disorders

They suggest the leading role of biological factors, including hereditary predisposition, as evidenced by the high concordance of the disorder in identical twins, and tissue damage to brain structures with disruption of the formation of interanalyzer connections: auditory, visual, kinesthetic. Interaction with non-biological factors, such as the lack of favorable conditions for obtaining an education, low social level of the family, neglect, complicates the course of reading disorder.

How does reading disorder manifest itself?

Reading disorders are characterized by specific disorders that manifest themselves both in a slow reading rate and in numerous persistent errors, such as:

• omissions, substitutions, distortions or additions of words or parts of words;
• rearrangement of words in a sentence or letters in words;
• prolonged hesitation or “losing one’s place” in the text and inaccuracies in expressions.

As a rule, there is a characteristic lack of understanding of what has been read; children cannot remember individual facts, draw conclusions or inferences from what they have read.

Specific reading disorders are usually preceded by speech development disorders. In school age, concomitant emotional and behavioral disorders are typical.

Classification

The following types of reading disorders are distinguished:

• optical reading disorder, expressed in difficulties in learning individual letters that are similar in spelling, and the inability to grasp a word at one time;
• a motor reading disorder characterized by a disorder in the reproduction of syllables, words, phrases, in their visual control and retention of articulatory positions in memory;
• phonemic literal reading disorder characterized by mixing letters that are similar in acoustic features. In oral reading, this disorder manifests itself in omissions, distortions (of vowels and consonants), substitutions in the pronunciation of soft-hard, voiced-voiceless, sibilant-hissing consonants. A connection is often traced between the disruption of the functions of phonemic perception and motor reproduction;
• Phonemic verbal reading disorders are expressed in omissions, substitutions, distortions of words, hesitations on words with complex sound structure. At the phrase level, verbal dyslexias lead to word rearrangements, difficulties in comprehension and inability to generalize what has been read. Phonemic verbal dyslexias are usually combined with phonemic literal dyslexias.

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How to recognize reading disorder?

Diagnostic algorithm (according to ICD-10)

• Presence of any of the signs. 
  • The reading accuracy and/or reading comprehension score is two standard errors below the level expected for the child's age and general intellectual development (reading skills and IQ are determined by an individually assigned test that takes into account cultural conditions and the education system in a standardized manner).
  • History of severe reading difficulties or test scores meeting criterion A at an earlier age; spelling test score at least two standard errors below the level expected for the child's chronological age and corresponding IQ.
• The impairments described in criterion A substantially interfere with learning or activities of daily living that require reading skills.
• This disorder is not a direct result of a visual, hearing or neurological defect.
• School experience (except reading) is in line with average expected level.

Differential diagnostics

In the course of diagnostic measures, it is necessary to exclude secondary reading disorders caused by mental retardation, decreased hearing and vision acuity, social deprivation and pedagogical neglect. Differential diagnostics with reading difficulties caused by linguistic (interethnic) factors is also required.

In this regard, it is necessary to conduct the following examinations: consultation with a speech therapist, neurologist, neuropsychologist, psychologist, psychiatrist, instrumental studies - EEG, EchoEG, REG (in cases requiring differential diagnosis with sluggish neurological diseases). Additionally, consultations with an audiologist and geneticist are prescribed.

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Treatment of reading disorders

Of primary importance in developing reading is a special set of speech therapy sessions, both individual and in groups. The duration of the course of corrective measures depends on the severity of dyslexia and can be 180 or more sessions. In order to activate the activity of brain structures, therapy is carried out using various neurometabolic stimulants (GABA derivatives and analogues, cerebrovascular agents, polypeptides, organic composites, etc.). In the presence of concomitant emotional and behavioral disorders, sedatives and antidepressants are added. Physiotherapy, therapeutic physical training, and massage are prescribed as additional therapeutic measures.

What is the prognosis for reading impairment?

Improving reading skills in the process of therapeutic and corrective measures.