Dyslexia is a disorder of learning written language. It is part, with dysphasia, dyspraxia or dyscalculia, specific disorders of learning. This disorder may concern children normally attending school with no sensory problems (hearing, vision), intellectual disability or neurological damage. On the other hand, these children suffer from a written language disorder with a reading delay of at least 18 months.
Dyslexia can lead, beyond reading difficulties, to social, behavioral or anxiety problems.
There are three types of dyslexia: phonological dyslexia, surface dyslexia and mixed dyslexia.
The phonological dyslexia is characterized by a difficulty to “read” words (see box). The surface dyslexia is a difficulty in recognizing a word in its entirety. The mixed dyslexia combines the two types listed above dyslexia.
|To better understand the processes involved in dyslexia: how do we read?
According to many works, reading is the product of two skills: the identification of written words and comprehension. Dyslexia is primarily due to a problem of identification of written words, even if comprehension problems remain.
To read a word, there would be two processes:
Dyslexia affects 5% of children. Nearly 1% of them would have a severe disability.
Diagnostic of Dyslexia
Screening for dyslexia must be early, but it cannot be done before 18 months of reading. It is multidisciplinary. The child can be spotted by his teacher. Some signs such as poor pencil holding, refusal to write, illegible writing, or poor work should alert.
The teacher can propose a medical consultation, the doctor then referring him to a speech therapist, an orthopedagogue and a psychologist. Reference Centers for Learning Disorders (CRDTA), made up of a multidisciplinary team and present in many regions, can also be diagnosed with dyslexia.
Different global tests of cognitive functions (memory, attention …), reading and language are proposed. These include the screening tool Odedys or test of Tom Thumb, which allows short text, from the playing time and the number of errors, to estimate the severity of dyslexia.
Eye exams, hearing tests and neurological examinations are also performed. Just like psychological tests. They can eliminate other parameters that may be responsible for reading difficulties. This comprehensive assessment will confirm or not dyslexia.
Causes of Dyslexia
The causes of dyslexia are still unknown. Several scientific hypotheses are advanced. The phonological theory admits the greatest consensus. According to this theory, dyslexic people suffer from a disturbance in the representation and mental manipulation of speech sounds. The visual theorysuggests in turn that some children have visual attentional disorders. Finally, a problem of migration of neurons is sometimes called into question. The neurons involved in reading are born in a non-specific area of the brain and then migrate to the area of the brain dedicated to reading. In dyslexics, this migration would not happen normally.
These abnormalities may be of genetic origin (family history is common in dyslexia) but this remains to be confirmed. Some researchers have found an abnormality in chromosome 15, others in chromosome 18.
Dyslexic children almost always present with associated dysorthography (difficulties in spelling). Dyslexia is also linked in more than half of the cases to oral language disorders that appeared in early childhood.
Dyslexia increases the risk of developing hyperactivity and attention deficit disorder (ADHD). We can find problems of memorization, coordination or lateralization.
Consequences of Dyslexia
The consequences are very variable depending on the severity of the disorders. Children with dyslexia often face academic difficulties that can result in malaise, aggression or inappropriate behavior.
In France, dyslexic children benefit from a Personalized School Project (PPS). This document allows parents, teachers, re-educators and the child to work together on a project. The latter specifies the details of the course of the child’s schooling and the necessary adjustments (computer, extra time …). It identifies and articulates all the educational, educational, medical and paramedical actions undertaken with the child.
Symptoms of dyslexia
The symptoms of dyslexia are sometimes difficult to detect. Some signs are however visible before learning to read.
Possible signs before primary school:
- Late language
- Difficulty learning new words, constructing sentences;
- Difficulty recognizing letters
- An inability to rhyme
- A tendency to encounter difficulties to write his name;
- Insufficient immediate memory;
- Difficulty locating in space
Signs in primary school:
- Difficulty learning to read
- A slowness vis-à-vis the writing;
- A lack of attention;
- Concerns of understanding;
- Difficulty in differentiating some close words;
- Difficulty responding to multiple requests at the same time
- A problem to differentiate certain letters (the b and the d for example) or certain words;
- A difficulty in cutting an unknown word into several syllables, spelling, pronouncing long words;
- Difficulty in learning a foreign language
- A tendency not to memorize the alphabet or the days of the week;
- Problems of coordination, motor skills.
The difficulties faced by adults are the same as those encountered by children if their dyslexia has not been managed. Although early intervention is desirable, it is never too late to treat dyslexia.
- Difficulty reading, including aloud
- Difficulty in understanding certain traits of humor or proverbs;
- Spelling problems
- A difficulty in summarizing a story;
- Difficulty in learning a foreign language
- Difficulty taking notes.
People at risk for Dyslexia
People with a family history of dyslexia.
Risk factors for Dyslexia
Many factors, genetic or environmental for example, may explain the development of dyslexia. A combination of these factors is certainly at the origin of the appearance of dyslexia.
It is difficult to prevent the appearance of dyslexia. Prevention ultimately involves early detection.
Medical treatments for dyslexia
There is no medicine that can cure dyslexia. In case of attention deficit disorder with or without hyperactivity (ADHD) associated with dyslexia, medications may be offered.
The treatment of dyslexia involves sessions with the speech therapist. A speech therapy rehabilitationcan propose strategies of compensation to the dyslexic person. Of sessions with the therapist are sometimes useful. An orthoptist, a psychomotor therapist or an occupational therapist may also intervene. The management of dyslexia is therefore multidisciplinary.
Regarding rehabilitation, there are many techniques that allow a dyslexic child to learn to read more easily. We can cite, for example, the Tomatis method, based on the “reeducation of listening”, the Borel-Maisonny method which combines gesture and sound or the “La planète des Alphas” method where the characters have the form and make the sound of the letters of the alphabet.
Omega-3. For effects on the brain and neurons, omega-3s have been tested in dyslexia clinical trials. Some researchers have suggested that dyslexic children have a low blood concentration of polyunsaturated fatty acids including omega-3. However, the results on the effect of supplementation remain uncertain.
Music therapy. One study suggested the interest of music therapy in the management of dyslexia. Singing and rhythm exercises would improve the hearing skills of dyslexic children and promote their language learning.