Dyslexia: Common Neurodevelopment Learning Disorder
Dyslexia the most common neurodevelopment learning disorder with a prevalence of 5-12% of children being diagnosed (Schumacher, Hoffmann, Schmal, Schulte-Korne, & Nothen, 2007). Dyslexia is a learning disorder that is usually identified in childhood years, typically when a child reaches school age. This disorder causes individuals to have trouble reading, writing or spelling. Dyslexia affects the part of the brain that processes language and is responsible for decoding words. This leads to difficulty identifying speech sounds and learning how they relate to letters and words. Dyslexic individuals usually have normal intelligence and although there is no cure, many people learn ways to overcome and cope with the learning disorder and end up being successful in life while others attain a lower level of education and have higher levels of unemployment (Mayo Clinic, 2017).
The etiology of dyslexia is still diverse and not completely known. There are many suggestions and assumptions regarding the etiology such as heredity, the structure of the brain, visual processing difficulties and auditory processing difficulties. Neurologists, scientists and speech and language therapist are still researching the exact cause of dyslexia (Georgiou, 2010).
As mentioned above, some research shows that dyslexia may be hereditary. A child with a parent that has dyslexia has a 40-60% chance of developing the disability. If other family members are also affected the risk for developing dyslexia is greatly increased. Research also shows that males are more susceptible to inheriting the disease versus females (Schumacher et al., 2007). Other research shows that dyslexic individuals have an abnormal brain structure. The left hemisphere is responsible for language processing, speech and reading. It was found that in the dyslexic brain, temporoparietal language areas on each side were symmetrical rather than the left side being larger. The brain of non-dyslexic individuals is normally asymmetrical with the left hemisphere being larger than the same area on the right. Studies have also shown that dyslexic people have less gray matter than a non-dyslexic person, resulting in problems processing sounds and language structure (Hudson, High, Otailba, n.d.). Other studies have shown that dyslexia may also be due to poor vision, causing individuals to have problems clearly seeing the letters and being able to place them in the correct order. It is believed that the magnocellular nerve cell had developed abnormally in dyslexic people. The magnocellular nerve cell is responsible for the ability to rapidly identify letters and the order in which they go because the nerve cell controls visual guidance and fixations of the eye. (Stein, 2014). The last cause of dyslexia that has been studied is the role of auditory processing. Research has shown that 43% of dyslexic people also have an auditory processing disorder. Brain images on dyslexic people have shown that brain wave responses to sound have impairments in the neural encoding of elements that are responsible for differentiating different sounds, such as pitch and timing differences in speech sounds. Studies believe this contributes to the inability to hear a word correctly and say it out loud in the same way. For example, the word “bat” might be heard as “bap” or “pat” (Auditory Processing Center, n.d.).
As previously stated, dyslexia is a neurologic learning disorder that causes to people to struggle with reading, writing, spelling, and pronouncing words correctly. The disorder may also affect motor skills, causing children to have difficulty holding a pencil. Dyslexia is usually first noticed once a child starts preschool and some first signs might be trouble recognizing that two words rhyme, struggling with learning new words, the inability to recognize letters and match them to different sounds as well as being able to understand the sound that a word starts with. For example, the letter “S” in the word “shed” might be repeated back as “fred”. As the dyslexic child gets older they might have trouble with forgetting how to spell words they have previously studied, as well as trouble with math word problems, frequently has to re-read sentences and may read at a lower academic level. As a child with dyslexia gets older, the inability to read correctly may start to affect their self-esteem, causing them to be embarrassed or feel incompetent compared to their peers. It is important for parents to identify dyslexia symptoms early on so that teachers, aids, and other interventions can be taken to assist the child in coping with the disorder. Sometimes dyslexic children will try and hide their disorder and avoid reading out loud, causing the symptoms to progress into middle school and high school. If therapy is started once the symptoms are first noticed, there is a greater chance in being able to help them modify their reading and speaking (Eden, G., n.d.). Children that are dyslexic are also known to have ADHD, attention-deficit hyperactivity disorder. This may worsen the symptoms of dyslexia, causing the child to have difficulty staying focused during reading and other school activities. (Eden, G., n.d.)
There are no systemic or clinical findings for dyslexia itself, although the poor motor skills that comes with dyslexia and the ADHD may cause poor home care that can lead to accumulation of biofilm and caries.
Therapy for dyslexia starts out with a complex diagnosis, which includes assessing the child’s overall development, educational issues and medical history. The child’s home life will be taken into consideration such as who all lives in the home and any problems that are present. The child may be asked to take different tests, so the doctor can identify any reading or language issues. Vision, hearing and neurological tests may be done to rule out any other disorder or abnormalities that might be causing the dyslexia symptoms. Psychological testing could also be done to determine the mental health of the individual and to see if any social, anxiety or depression may be limiting the child rather than the dyslexia. Once a child is diagnosed with dyslexia, different educational approaches will be taken to improve reading and writing skills. Teachers and aids may use different techniques that involve vision, hearing, and touch. Different programs are put into place in public schools in the United States, one example is the Individualized Education Plan (IEP). These programs are in schools to help children diagnosed with dyslexia or other learning disabilities to overcome and learn to process information properly. Dyslexia doesn’t ever go away completely, but with early detection and intervention as a child, it is manageable as an adult (Mayo Clinic, 2017).
Dyslexic patients may need special modifications depending on each case. If the patient has slower motor skills, they may need extra assistance in hygiene instruction such as how to hold and angle the toothbrush. Dental hygienists should also educate the parents on oral hygiene importance and have them assist their children at home to make sure biofilm removal is getting done properly.
- Auditory Processing Center. (n.d.). APD, Dyslexia, or both? Retrieved from https://www.auditorycenter.com/what-is-auditory-processing-disorder/apd-dyslexia-or- both/
- Eden, G. (n.d.). Understanding Dyslexia. Retrieved from https://www.understood.org/en/learning-attention-issues/child-learning- disabilities/dyslexia/understanding-dyslexia
- Georgiou, A.M. (2010, January). Dyslexia: Etiology-characteristics-assessment from the view of the clinical speech and language practice. E-Journal of Science and Technology, 2(5), 23
- Hudson, R.F., High, L., Otailba, S. (n.d.). Dyslexia and the brain: what does current research tell us? Retrieved from http://www.Idonline.org/article/14907
- International Dyslexia Association. (n.d.). Dyslexia and the brain. Retrieved from https://dyslexiaida.org/dyslexia-and-the-brain-fact-sheet/
- Mayo Clinic. (2017, July 22). Dyslexia. Retrieved from https://www.mayoclinic.org/diseases- conditions/dyslexia/symptoms-causes/syc-20353552
- Schumacher, J., Hoffmann, P., Schmal, C., Schulte-Korne, G., & Nothen, M. M. (2007). Genetics of dyslexia: The evolving landscape. Journal of Medical Genetics,44(5), 289- doi:10.1136/jmg.2006.046516
- Stein, J. (2014). Dyslexia: The Role of Vision and Visual Attention. Current Developmental Disorders Reports,1(4), 267-280. doi:10.1007/s40474-014-0030-6