Dyslexia Symptoms, Causes, and Management

Dyslexia, also known as reading disorder, is a disorder characterized by difficulty reading in individuals with otherwise unaffected intelligence. Different people are affected to different degrees. Problems may include difficulties in spelling words, reading quickly, writing words, “sounding out” words in the head, pronouncing words when reading aloud, and understanding what one reads. Often these difficulties are first noticed at school. When someone who previously could read loses their ability, it is known as “alexia”. The difficulties are involuntary and people with this disorder have a normal desire to learn. People with dyslexia have higher rates of attention deficit hyperactivity disorder (ADHD), developmental language disorders, and difficulties with numbers. Siddha Spirituality of Swami Hardas Life System lets you know in-depth about dyslexia for well-being.

Dyslexia Meaning

Dyslexia is a learning disorder that affects your ability to read, spell, write, and speak. Kids who have it are often smart and hardworking, but they have trouble connecting the letters they see to the sounds those letters make.

Dyslexia Classification

Dyslexia is divided into developmental and acquired forms. This article is primarily about developmental dyslexia i.e. dyslexia that begins in early childhood. Acquired dyslexia occurs subsequent to neurological insults, such as traumatic brain injury or stroke. People with acquired dyslexia exhibit some of the signs or symptoms of the developmental disorder, but require different assessment strategies and treatment approaches.

Dyslexia Symptoms

Early childhood

In early childhood, symptoms that correlate with a later diagnosis of dyslexia include delayed onset of speech and a lack of phonological awareness. A common myth closely associates dyslexia with mirror writing and reading letters or words backward. These behaviors are seen in many children as they learn to read and write, and are not considered to be defining characteristics of dyslexia.

School going children

School-age children with dyslexia may exhibit signs of difficulty in identifying or generating rhyming words, or counting the number of syllables in words–both of which depend on phonological awareness. They may also show difficulty in segmenting words into individual sounds or may blend sounds when producing words, indicating reduced phonemic awareness. Difficulties with word retrieval or naming things are also associated with dyslexia. People with dyslexia are commonly poor spellers, a feature sometimes called dysorthographia or dysgraphia, which depends on orthographic coding.

Adolescence and adulthood

Problems persist into adolescence and adulthood and may include difficulties with summarizing stories, memorization, reading aloud, or learning foreign languages. Adults with dyslexia can often read with good comprehension, though they tend to read more slowly than others without a learning difficulty and perform worse in spelling tests or when reading nonsense words–a measure of phonological awareness.

Dyslexia associated conditions

Dyslexia often co-occurs with other learning disorders, but the reasons for this comorbidity have not been clearly identified. These associated disabilities include:

Dysgraphia

A disorder involving difficulties with writing or typing, sometimes due to problems with eye-hand coordination; it also can impede direction- or sequence-oriented processes, such as tying knots or carrying out repetitive tasks. In dyslexia, dysgraphia is often multifactorial, due to impaired letter-writing automaticity, organizational and elaborative difficulties, and impaired visual word forming, which makes it more difficult to retrieve the visual picture of words required for spelling.

Attention deficit hyperactivity disorder (ADHD)

A disorder characterized by problems sustaining attention, hyperactivity, or acting impulsively. Dyslexia and ADHD commonly occur together. Approximately 15% or 12–24% of people with dyslexia have ADHD, and up to 35% of people with ADHD have dyslexia.

Auditory processing disorder

A listening disorder that affects the ability to process auditory information. This can lead to problems with auditory memory and auditory sequencing. Many people with dyslexia have auditory processing problems and may develop their own logographic cues to compensate for this type of deficit. Some research suggests that auditory processing skills could be the primary shortfall in dyslexia.

Developmental coordination disorder

A neurological condition characterized by difficulty in carrying out routine tasks involving balance, fine-motor control, kinesthetic coordination, difficulty in the use of speech sounds, problems with short-term memory, and organization.

Dyslexia Causes

Researchers have been trying to find the neurobiological basis of dyslexia since the condition was first identified in 1881. For example, some have tried to associate the common problem among people with dyslexia of not being able to see letters clearly to the abnormal development of their visual nerve cells.

Neuroanatomy

Functional magnetic resonance imaging

Neuroimaging techniques, such as functional magnetic resonance imaging (fMRI) and positron emission tomography (PET), have shown a correlation between both functional and structural differences in the brains of children with reading difficulties. Some people with dyslexia show less electrical activation in parts of the left hemisphere of the brain involved with reading, such as the inferior frontal gyrus, inferior parietal lobule, and the middle and ventral temporal cortex. Over the past decade, brain activation studies using PET to study language have produced a breakthrough in the understanding of the neural basis of language. 

Cerebellar theory

The cerebellar theory of dyslexia proposes that impairment of cerebellum-controlled muscle movement affects the formation of words by the tongue and facial muscles, resulting in the fluency problems that some people with dyslexia experience. The cerebellum is also involved in the automatization of some tasks, such as reading. The fact that some children with dyslexia have a motor task and balance impairments could be consistent with a cerebellar role in their reading difficulties. 

Genetics

Research into potential genetic causes of dyslexia has its roots in the post-autopsy examination of the brains of people with dyslexia. Observed anatomical differences in the language centers of such brains include microscopic cortical malformations known as ectopias, and more rarely, vascular micro-malformations, and microgyrus—a smaller than usual size for the gyrus. The previously cited studies and others suggest that abnormal cortical development, presumed to occur before or during the sixth month of fetal brain development, may have caused the abnormalities.

Gene-environment interaction

The contribution of gene-environment interaction to reading disability has been intensely studied using twin studies, which estimate the proportion of variance associated with a person’s environment and the proportion associated with their genes. Both environmental and genetic factors appear to contribute to reading development. Studies examining the influence of environmental factors such as parental education and teaching quality have determined that genetics have greater influence in supportive, rather than less optimal, environments. However, more optimal conditions may just allow those genetic risk factors to account for more of the variance in the outcome because the environmental risk factors have been minimized.

As the environment plays a large role in learning and memory, it is likely that epigenetic modifications play an important role in reading ability. Measures of gene expression, histone modifications, and methylation in the human periphery are used to study epigenetic processes; however, all of these have limitations in the extrapolation of results for application to the human brain.

Language

The orthographic complexity of a language directly affects how difficult it is to learn to read it. English and French have comparatively “deep” phonemic orthographies within the Latin alphabet writing system, with complex structures employing spelling patterns on several levels: letter-sound correspondence, syllables, and morphemes. 

Languages such as Spanish, Italian and Finnish have mostly alphabetic orthographies, which primarily employ letter-sound correspondence—so-called “shallow” orthographies—which makes them easier to learn for people with dyslexia. 

Logographic writing systems, such as Chinese characters, have extensive symbol use; and these also pose problems for dyslexic learners.

Dyslexia Pathophysiology

Most people who are right-hand dominant have the left hemisphere of their brain specialize more in language processing. In terms of the mechanism of dyslexia, fMRI studies suggest that this specialization may be less pronounced or even absent in cases with dyslexia. Additionally, anatomical differences in the corpus callosum, the bundle of nerve fibers that connects the left and right hemispheres, have been linked to dyslexia via different studies.

Data via diffusion tensor MRI indicate changes in connectivity or in gray matter density in areas related to reading/language. Finally, the left inferior frontal gyrus has shown differences in phonological processing in people with dyslexia. Neurophysiological and imaging procedures are being used to ascertain phenotypic characteristics in people with dyslexia thus identifying the effects of certain genes.

Dual route theory

The dual-route theory of reading aloud was first described in the early 1970s. This theory suggests that two separate mental mechanisms, or cognitive routes, are involved in reading aloud. One mechanism is the lexical route, which is the process whereby skilled readers can recognize known words by sight alone, through a “dictionary” lookup procedure. 

The other mechanism is the nonlexical or sublexical route, which is the process whereby the reader can “sound out” a written word. This is done by identifying the word’s constituent parts and applying knowledge of how these parts are associated with each other, for example, how a string of neighboring letters sounds together. The dual-route system could explain the different rates of dyslexia occurrence between different languages.

Dyslexia Diagnosis

Dyslexia is a heterogeneous, dimensional learning disorder that impairs accurate and fluent word reading and spelling. Typical—but not universal—features include difficulties with phonological awareness; inefficient and often inaccurate processing of sounds in oral language (phonological processing); and verbal working memory deficits.

Dyslexia is not a problem with intelligence. Emotional problems often arise secondary to learning difficulties. The National Institute of Neurological Disorders and Stroke describes dyslexia as “difficulty with phonological processing (the manipulation of sounds), spelling, and/or rapid visual-verbal responding”.

Assessment

• Strive for a multidisciplinary team approach involving the child’s parent(s) and teacher(s); school psychologist; pediatrician; and, as appropriate, speech and language pathologist (speech therapist); and occupational therapist.
• Possess a thorough familiarity with typical ages children to reach various general developmental milestones, and domain-specific milestones, such as phonological awareness.
• Avoid over-reliance on tests. Careful observation of the child in the school and home environments, and sensitive, comprehensive parental interviews are just as important as tests.
• Take advantage of the empirically supported “response to intervention” (RTI) approach.

Assessment tests for Dyslexia

There is a wide range of tests that are used in clinical and educational settings to evaluate the possibility that a person might have dyslexia. These tests and observations can include:

Measuring cognitive ability

General measures of cognitive ability, such as the Wechsler Intelligence Scale for Children, Woodcock-Johnson Tests of Cognitive Abilities, or Stanford-Binet Intelligence Scales. The low general cognitive ability would make reading more difficult. Cognitive ability measures also often try to measure different cognitive processes, such as verbal ability, nonverbal and spatial reasoning, working memory, and processing speed. There are different versions of these tests for different age groups. 

Screening or evaluation for mental health conditions

Behavior checklists

Parents and teachers can complete rating scales or behavior checklists to gather information about emotional and behavioral functioning for younger people. Many checklists have similar versions for parents, teachers, and younger people old enough to read reasonably well to complete. Examples include the Behavioral Assessment System for Children, and the Strengths and Difficulties Questionnaire. All of these have nationally representative norms, making it possible to compare the level of symptoms to what would be typical for the younger person’s age and biological sex.

Psychiatric checklists

Other checklists link more specifically to psychiatric diagnoses, such as the Vanderbilt ADHD Rating Scales or the Screen for Child Anxiety Related Emotional Disorders (SCARED). Depressive disorders and anxiety disorders are two-three times higher in people with dyslexia, and attention-deficit/hyperactivity disorder is more common, as well.

Review of academic achievement and skills

Average spelling/reading ability for a dyslexic is a percentage ranking <16, well below normal. In addition to reviewing grades and teacher notes, standardized test results are helpful in evaluating progress. These include group-administered tests, such as the Iowa Tests of Educational Development, that a teacher may give to a group or whole classroom of younger people at the same time. They also could include individually administered tests of achievement, such as the Wide Range Achievement Test, or the Woodcock-Johnson. The individually administered tests again require more specialized training.

Dyslexia Screening

Family history

Screening procedures seek to identify children who show signs of possible dyslexia. In the preschool years, a family history of dyslexia, particularly in biological parents and siblings, predicts an eventual dyslexia diagnosis better than any test.

In primary school (ages 5–7), the ideal screening procedure consists of training primary school teachers to carefully observe and record their pupils’ progress through the phonics curriculum, and thereby identify children progressing slowly. When teachers identify such students they can supplement their observations with screening tests such as the Phonics screening check used by United Kingdom schools during Year one.

Psychiatrist M. S. Thambirajah

In the medical setting, child and adolescent psychiatrist M. S. Thambirajah emphasizes that “given the high prevalence of developmental disorders in school-aged children, all children seen in clinics should be systematically screened for developmental disorders irrespective of the presenting problem/s.” Thambirajah recommends screening for developmental disorders, including dyslexia, by conducting a brief developmental history, a preliminary psychosocial developmental examination, and obtaining a school report regarding academic and social functioning.

Dyslexia Management

Through the use of compensation strategies, therapy, and educational support, individuals with dyslexia can learn to read and write. There are techniques and technical aids that help to manage or conceal symptoms of the disorder. 

Reinforced collateral training

Reducing stress and anxiety can sometimes improve written comprehension. For dyslexia intervention with alphabet-writing systems, the fundamental aim is to increase a child’s awareness of correspondences between graphemes (letters) and phonemes (sounds) and to relate these to reading and spelling by teaching how sounds blend into words. Reinforced collateral training focused on reading and spelling may yield longer-lasting gains than oral phonological training alone. Early intervention can be successful in reducing reading failure.

Dyslexie and OpenDyslexic Fonts

Research does not suggest that specially-tailored fonts (such as Dyslexie and OpenDyslexic) help with reading. Children with dyslexia read text set in a regular font such as Times New Roman and Arial just as quickly, and they show a preference for regular fonts over specially-tailored fonts. Some research has pointed to increased letter-spacing being beneficial.

There is currently no evidence showing that music education significantly improves the reading skills of adolescents with dyslexia.

Dyslexia Research