Dyslexia: Definition, Characteristics, Causes, Symptoms, Comorbidity, Diagnosis and Treatment

It is a learning difficulty that mainly affects the skills involved in reading and spelling words.

Characteristics of dyslexia

The main features are:

  • The difficulties in phonological awareness.
  • On verbal memory.
  • The speed of verbal processing.

Dyslexia occurs throughout the range of intellectual abilities.


Researchers have not yet identified exactly what causes dyslexia. But they do know that genes and brain differences play a role.

These are some of the possible causes of dyslexia:

Genes and inheritance

Dyslexia often occurs in families. About 40 percent of siblings of children with dyslexia have the same reading problems.

Up to 49 percent of parents of children with dyslexia also have it. Scientists have also found a number of genes linked to problems with the language of reading and processing.

Anatomy and activity of the brain

Brain imaging studies have shown brain differences between people with and without dyslexia. These differences occur in areas of the brain involved with key reading skills.

These skills are knowing how sounds are represented in words and recognizing how words are written.

Symptoms and signs of dyslexia

In preschool group

  • Difficulty recognizing the letters of the alphabet.
  • Delays in the language.
  • Problems with rhyme
  • Difficulty with the sounds of the letters.

The story of someone in the family with dyslexia or another learning disability is sometimes seen in these young people.

In the first grades of primary school

  • Difficulty reading single words (especially without visual cues or context).
  • Difficulty with “nonsense” or pseudowords.
  • Low reading speed
  • Bad grammar.
  • Numerous substitutions of letters.
  • Generally good numerical concepts of mathematics.

In later grades of primary and secondary

  • As mathematics implies more language, greater mathematical difficulties.
  • Difficulty completing tasks that involve reading large passages of text.
  • Problems with the comprehension of the reading passages.


Children with dyslexia may have simultaneous disorders (often called “comorbid”) that interfere with learning.

Comorbid conditions

Attention deficit hyperactivity disorder (ADHD)

This neurological disorder mainly affects attention and organization, and may be accompanied by hyperactivity and impulsivity.

This can seriously affect the learning of a child who has already been affected by dyslexia.

Affective disorders (anxiety, depression )

Children with dyslexia may have low self-esteem related to their academic problems and are prone to depressive and anxiety disorders.

These are usually identified by the change in the habitual pattern of behavior and the academic deterioration of a child accompanied by abandonment of activities, increased irritability, mood swings, avoidance of the school, change of alertness, eating, sleeping and eating habits. game.

Behavioral disorders (ODD, CD)

Some children may show negative behavior, challenge authority and aggressive behavior in class, and avoid class work.

Oppositional defiant disorder (ODD) interferes even more with learning and relationships with classmates in a class setting.

Diagnosis of dyslexia

The diagnosis of dyslexia is not simple and often needs the opinion of several different professionals.

Although it is a disorder that affects learning and is considered predominantly part of the educational field, there are also neurological and medical problems at stake, so a cooperative effort between the school, the doctor and other health professionals is essential to attend to the child and family.

The centerpiece of a diagnosis of “learning disability” in schools is the demonstration of a difference or “discrepancy” between the child’s IQ and his or her academic achievement or “achievement.”

This criterion of discrepancy has been widely debated between the research community and the educational community, however, at present, it remains an important consideration.

This was done so that exceptionally gifted children could remain disabled for learning and have difficulty with reading and spelling, but perform in those subjects at the level of their peers, and ignore if one only bases the diagnosis on the performance below one classmates.

Many children with dyslexia are overlooked until they are in elementary school or upper secondary school, when there is a noticeable decline in academic performance.

They often do not “fall two degrees behind their grade level”, which in many systems is the limit to providing recovery services, so they continue to struggle without intervention.

Furthermore, there is a confounding factor in the use of typical school-based discrepancy criteria, since many IQ tests rely on strong language skills that are inherently weaker in many children with dyslexia, thus reducing the “discrepancy” and nullifying a conclusive diagnosis of dyslexia. .

There is also an ongoing argument among medical and educational professionals about the terminology related to reading disorder.

Many educators do not believe that “dyslexia” is a valid term; Many doctors believe that the term ” learning disabilities ” is applied too broadly to indicate the specific deficits a child has.

A community specialist, such as a pediatrician or behavioral development neurologist, could use screening tools such as the wide-ranging performance test (WRAT) or the Peabody individual achievement test (PIAT, for example). its acronyms in English).

These can identify domains of concern, but they should not be construed as definitive diagnostic tests. The latter can only be done by educational specialists or psychologists who are experts in the administration of IQ and performance tests.

Typical IQ tests in schools include the Wechsler WISC-IV test, and performance is measured by a battery of academic tests included in the Woodcock-Johnson test or the Wechsler Achievement test (WIAT) or similar tests.

The choice of tests may vary based on the preferences of the school district.

In general, behavioral data and speech and language tests may also be performed depending on the determination of the special education committee of the school system.

Role of the health professional in dyslexia

Because dyslexia is a complex neurological disorder, there is a role for the doctor in the care of children with dyslexia, even though the treatments are mainly educational.

The doctor can perform a physical examination and order screening tests, such as vision and hearing tests, to rule out any contributing deficits.

The doctor also plays an important role in the identification of neurological conditions such as attention deficit hyperactivity disorder (ADHD), either through screening or deriving subspecialists such as psychiatrists, neurologists or developmental pediatricians.

If ADHD is diagnosed, the doctor plays a vital role in prescribing medications to help control the symptoms of ADHD and, therefore, contributes to the child’s overall behavior in the task.

It should be remembered that there is no blood test or a brain scan test for dyslexia.


Although dyslexia is a lifelong neurological disorder that can not be “overcome,” there are many different strategies that can be used, especially at the beginning of academic life to help these people.

The early focus (before the fifth and sixth grades) is on “remediation.”

This means that strategies are used to help the child learn to improve deficits in the particular area of ​​disability, for example, reading decoding, reading comprehension or reading speed.

A child should receive instructions on how to recognize the sounds of letters, how to identify letters and how they correlate with sound.

Then, the approach is based on decoding with skills to combine sounds into words and divide the words into component sounds.

Gradually, a child is taught to focus on the content of the reading material, not only focusing on individual words, but how to look for sections that convey meaning for understanding.

The “guided oral reading” strategy provides feedback to the child in order to identify areas of error and teach alternative ways of approaching the task at hand.

A popular and well researched strategy is “multisensory learning”. This includes the use of auditory, visual and sometimes tactile strategies to help the child recognize and retain written material to convey the meaning.

The material is organized to follow a sequential and logical pattern of learning, based on previously acquired skills or “scaffolding”.

This is often achieved through the direct instruction of a professional trained in special education, individualized for the needs of the child.

Some examples of this are the Orton-Gillingham method; and its variations, including the Slingerland Method, the Spalding Method, the Herman Method, the Wilson Reading Program and many others.

These strategies are well understood and used by special education teachers and several regular education teachers as well.

There is no perfect strategy, and each must adapt to meet the individual needs of a child. There are no direct comparisons that indicate that one method is preferred over the other.

The advantage of early detection and remediation is that it provides people with dyslexia the ability to compensate for deficits and learn appropriate strategies to apply to learning.

This helps reduce frustration and other emotional problems. Children should be monitored even after appropriate interventions are implemented to ensure that they continue to make progress in their learning.

This should be done periodically by the teacher and the family, but also by a formal review by the special education team of the school at least once a year.

This would help determine if the strategies employed allow the child to function more adequately in the learning environment. Otherwise, additional techniques or the exploration of other possible causes of the problem must be addressed.

The phonetic approach teaches the recognition of words through the systematic learning of correlations between letters and sounds.

The full-word approach teaches whole words in families of words or similar spelling patterns. The student is not taught directly the relationship between letters and sounds, but learns through the minimum differences between words.

As the child progresses, words that have irregular spellings are presented as recognizable words at first sight.

The advocates of each teaching system argue that their particular approach is the key to engaging children in reading.

There have been no overwhelming patterns of evidence-based research demonstrating a clear advantage of one approach over the other.

Today, many teachers seek an easy-to-use combination of both strategies; use phonics as part of the teaching of the complete language and, therefore, complement each approach.

A reasonable approach would be to become familiar with the philosophy of the school district regarding interventions for children with dyslexia, investigate whether individualized adaptations for the child are encouraged, and try to use strategies from both approaches in a systematic format.

Then, reviewing the results after a predetermined period would reveal if an improvement has been achieved.

Adaptations for dyslexia

Later in school life, and in adulthood, the focus is on “adaptations.”

This means that reasonable attempts must be made to adapt the curriculum and the method of instruction to allow the person with dyslexia to use alternative strategies for a given task.

These accommodations are usually requested under the Individualized Education Plan (IEP); however, in some cases they may be applied under a Section 504 plan under the Americans with Disabilities Act without the procedural safeguards of an IEP.

Some types of adaptations include:

  • Instructive.
  • Environmental.
  • Tests,
  • Assignment / task.
  • Assistive technology

There are excellent online and printed resources regarding the details of the above, but here are some examples:

  • Adjust the reading level.
  • Allow the student to record lectures.
  • Allow written or typed assignments to machine.
  • Provide a written outline.
  • Classroom environment
  • Seat the student near the teacher.
  • Provide a structured routine in written form.
  • Provide organizational strategies such as graphs, timelines, material folders, etc.
  • Allow testing of open books.
  • Offer multiple answers instead of short answers.
  • Allow the use of a dictionary or calculator during the test.
  • Provide extra time to finish.
  • Allow tests in an environment free of distractions.
  • Homework.
  • Allow the student to work on the assignment while at school.
  • Receive frequent reminders about expiration dates.
  • Give short assignments
  • Develop a reward system for the entire task.
Assistive technology (AT)

Assistive technology is any equipment or product used to increase, maintain or improve the functional capabilities of people with disabilities. It serves to increase the strengths of an individual and to provide an alternative way of performing a task.

Examples of technological solutions include:

  • Clocks, computer organizers to help with the organization.
  • Books.
  • The recorders help students review the materials in the class.
  • Voice recognition software to transcribe dictated reports.
  • An optical character recognition system to enter text or printed material into a computer through the use of a scanner.
  • Software programs such as spell checking to correct spelling and syntax errors.
  • Word processors to compose written text.

Care technology options should be explored through the school’s special education committee, usually with a child-assisted technology assessment to determine the “best fit” for the child’s needs.

The options for using home-assisted technology equipment should be explored to ensure the generalization of skills in different settings.

Support for dyslexia

In the House
  • Provide access to books at home or in the public library.
  • Spend time every day reading to have fun.
  • Choose reading materials according to the child’s interest.
  • Read to children often and give them time to read alone and in conjunction with the adult.
  • Play word games, rhymes, names, etc.
  • Try videotaping a child’s reading to provide feedback.
  • Spend small amounts of time with frequent breaks during reading tasks to avoid frustration.
  • Use lots of praise, limit criticism.
At school
  • Participate in the preparation of the child’s Individualized Education Plan (IEP).
  • Ask for frequent updates on the child’s progress.
  • Be familiar with the strategies that will be implemented in the school.
  • Request duplicates of the child’s homework to practice at home.
  • Communicate with school personnel.
  • Communicate information between the treating physician and the child’s school.

Non-medical therapies

Nutritional / Allergic Treatment

In view of the fact that it was reported long ago that niacin, B vitamins and related minerals improved the symptoms of dizziness and balance related to the inner ear, the previously noted favorable findings of nutritionists in dyslexia were easily made understandable

This if we consider its possible compensatory function to improve the transmission and processing of both normal and abnormal signals. For example, it was shown that ginger root is a highly effective antimaton disease or an inner ear enhancing substance.

In addition, it was shown that nutrients such as lecithin and ginkgo improve memory, while fatty acids and omega 3 sometimes improve concentration.

Also amino acids such as DL phenylalanine can decrease the levels of hyperactivity and increase the focus on lucky responders, occasionally avoiding the need for stimulants in a lucky few.

These nutritional substances can also allow doctors to lower the doses of the necessary stimulants and other medications, which reduces the risk of possible side effects.

On the contrary, some recognized allergist, have recognized that sugars, dyes and various other allergenic substances can aggravate and even trigger symptoms such as dyslexia / ADD such as hyperactivity, decreased concentration and distraction.

Consequently, the avoidance of these so-called “neurotoxic” substances in selected individuals resulted in a corresponding improvement.

According to studies, allergies often increase or trigger preexisting dyslexic / ADD symptoms further destabilizing the inner ear-related functioning.

They usually do not cause this disorder, unless the allergic attack is severe enough to primarily impair the inner ear and related CVS mechanisms and related brain structures.

In conclusion, dyslexia is frequent in our society, although it is not well recognized or understood, it is a lifelong affection that affects both children in school and adults in their vocational and social environments.

Adults with dyslexia exist and are often not recognized, as they seem to work well in society and tend to mask their disability or gravitate toward occupations that do not emphasize their disability.

Families and doctors should know the resources that exist in their communities and on the Internet for adults with dyslexia and allow access to these resources so that they can better compensate for their disability.

Research continues on the nature of dyslexia, the deficits that must be overcome and the strategies that can be used to achieve this goal.

People with dyslexia can learn to read, and with the right guidance, assistance and resources, they can do so with a sense of achievement, skill and confidence.