Dyslexia

Dyslexia is a learning disability that impairs a person’s ability to read. Although the disorder varies from person to person, common characteristics among people with dyslexia are difficulty with phonological processing (the manipulation of sounds), spelling and rapid visual-verbal responding. 

Learning disabilities are characterized by significant limitations both in intellectual functioning and in adaptive behavior as expressed in conceptual, social and practical adaptive skills. Such disabilities typically originate before age 18. 

Over the past decade, important changes have been made in disability terminology, resulting in the renaming of mental retardation to intellectual disability. Though this disability, which has a major impact on a patient’s life, is sometimes hard to diagnose, medical science has developed a better understanding of its causes. 

Learning disabilities are disorders that affect the ability to:

• Understand or use spoken or written language
• Do mathematical calculations
• Coordinate movements
• Direct attention

Learning disabilities occur in very young children, yet they are usually not noticed until the child reaches school age. Learning disabilities can be lifelong conditions with a range of impacts and accommodation requirements.

In some people, several overlapping learning disabilities may occur, with frequent overlap of attention-deficit disorder (ADD) and attention-deficit/hyperactivity disorder (ADHD) diagnoses. Other people may have a single, isolated learning problem that has little impact on their lives.

There is some incidence of learning disabilities in adults, such as adult-onset dyslexia. This usually occurs as a result of brain injury or dementia. However, some adults with dyslexia were never diagnosed with dyslexia as children or adolescents. Dyslexia can be inherited; recent studies have identified a number of genes that may predispose a person to developing dyslexia.

Dyslexia is either acquired as a result of a disease or traumatic brain injury, or it is genetic and therefore developmental. The different classifications of dyslexia are:

• Visual dyslexia: Difficulty reading due to problems with the eyes or cognitive or neurological causes 
• Surface dyslexia: Problems recognizing the whole word and words that don’t sound how they are spelled
• Double deficit dyslexia: Problems with the sounds in words
• Rapid naming dyslexia: Difficulty naming things quickly, including letters, colors and numbers
• Phonological dyslexia: Extreme difficulty reading

Most developmental disabilities are thought to be caused by a complex mix of factors. These factors include genetics, parental health and behaviors (such as smoking and drinking) during pregnancy, complications during birth, infections the mother might have during pregnancy or the baby might have very early in life, and exposure of the mother or child to high levels of environmental toxins, such as lead. For some developmental disabilities, such as fetal alcohol syndrome, which is caused by drinking alcohol during pregnancy, we know the cause. But for most, we don’t.

Developmental disabilities begin any time during the developmental period and usually last throughout a person’s lifetime. Most developmental disabilities begin before a baby is born, but some can happen after birth because of injury, infection or other factors.

Healthcare providers can play an important part in collaborating with schools to help a child with learning disorders or other disabilities get the special services they need. The American Academy of Pediatrics (AAP) has created a report that describes the roles that healthcare providers can have in helping children with disabilities, including learning disorders:

• Identifying children in need of early intervention or special education services
• Sharing relevant information with early intervention or school personnel
• Meeting with early intervention or school personnel and parents or guardians
• Using early intervention or school information in medical diagnostic or treatment plans
• Working within an early intervention, school or school-based health clinic
• Working at an administrative level to improve school functioning around children with special needs

To determine reading weaknesses, a dyslexia test assesses various skills such as phonological awareness, decoding, reading fluency, comprehension and rapid naming. The evaluator may also test for other language and processing issues that might be contributing. It's important to know that there isn't just one test to measure every skill, and the exact test used in the evaluation depends on the evaluator.

Some of the symptoms of learning disorders are:

• Difficulty telling right from left
• Reversing letters, words or numbers, after first or second grade
• Difficulties recognizing patterns or sorting items by size or shape
• Difficulty understanding and following instructions or staying organized
• Difficulty remembering what was just said or what was just read
• Lacking coordination when moving around
• Difficulty doing tasks with the hands, like writing, cutting or drawing
• Difficulty understanding the concept of time

For those with dyslexia, the symptoms present as difficulty with reading. The disability affects such a wide range of people and produces such different symptoms and varying degrees of severity that predictions are hard to make. The prognosis is generally good for individuals if it is identified early, especially if family and friends are supportive (and help the individual cultivate a strong self-image) and they participate in a proper remediation program.

Parents who think their child may have dyslexia may have them tested. A screening will include assessments of overall reading comprehension, decoding, challenges with reading and phonological awareness.

Children with learning disorders like dyslexia often need extra help and instruction that are specialized for them. Having a learning disorder can qualify a child for special education services in school. Schools usually do their own testing for learning disorders to see if a child needs intervention. An evaluation by a healthcare professional is needed if there are other concerns about the child’s behavior or emotions. Parents, healthcare providers and the school can work together to find the right referrals and treatment.

Treatment for dyslexia should focus on the specific learning problems of affected individuals. Generally, treatment includes modifying teaching methods and the educational environment to meet the specific needs of the individual with dyslexia.

Children with learning disorders often need extra help and instruction that are specialized for them. Having a learning disorder can qualify a child for special education services in school. Schools usually do their own testing for learning disorders to see if a child needs intervention. An evaluation by a healthcare professional is needed if there are other concerns about the child’s behavior or emotions. Parents, healthcare providers and the school can work together to find the right referrals and treatment.

The most common treatment for learning disabilities is special education. Specially trained teachers may perform a formal assessment to understand the child's academic and intellectual potential. They will also look at the level of academic performance. Once the evaluation is complete, the basic approach is to teach learning skills by building on the child's abilities and strengths while correcting disabilities and weaknesses. Other professionals such as speech and language therapists also may help. Some medications may help the child learn by enhancing attention and concentration. Psychological therapies may also be used.

Children with specific learning disabilities are eligible for special education services or accommodations at school under the Individuals with Disabilities in Education Act (IDEA).

The U.S. Department of Education issued a “Dear Colleague” letter providing clarification to both parents and practitioners about ensuring a high-quality education for children with specific learning disabilities, including children with dyslexia, dyscalculia and dysgraphia.

To develop a better understanding of your diagnosis, consider participating in a clinical trial so clinicians and scientists can learn more about learning disabilities and related disorders. Clinical research uses human volunteers to help researchers learn more about a disorder and perhaps find better ways to safely detect, treat or prevent disease.

All types of volunteers are needed—those who are healthy or may have an illness or disease—of all different ages, sexes, races and ethnicities to ensure that study results apply to as many people as possible, and that treatments will be safe and effective for everyone who will use them.

For information about participating in clinical research, visit NIH Clinical Research Trials and You. Learn about clinical trials currently looking for participants at Clinicaltrials.gov.