You are in: eMedicine Specialties > Pediatrics: Developmental and Behavioral > MEDICAL TOPICS Learning Disorder: ReadingArticle Last Updated: Feb 25, 2008AUTHOR AND EDITOR INFORMATIONSection 1 of 10
  Author: W Douglas Tynan, PhD, Chief Psychologist, Nemours Health and Prevention Division Programs; Director, Primary Care Mental Health Program, A I duPont Hospital for Children; Consulting Psychologist, Nemours Clinical Management W Douglas Tynan is a member of the following medical societies: American Academy of Pediatrics, American Psychological Association, Society for Developmental and Behavioral Pediatrics, and Society for Research In Child Development Editors: Angelo P Giardino, MD, PhD, Clinical Associate Professor, Department of Pediatrics, Baylor College of Medicine; Medical Director, Texas Children's Health Plan, Inc; Mary L Windle, PharmD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy, Pharmacy Editor, eMedicine.com, Inc; Carrie Sylvester, MD, MPH, Director of Education in Child and Adolescent Psychiatry, Professor, Departments of Psychiatry and Pediatrics, Northwestern University Medical School; Caroly Pataki, MD, Professor of Clinical Psychiatry, Department of Psychiatry and Biobehavioral Sciences, Division Chair of Child and Adolescent Psychiatry, Director of Training, Child and Adolescent Psychiatry Residency Program, University of Southern California Keck School of Medicine Author and Editor Disclosure Synonyms and related keywords: learning disorder, dyslexia, incomplete alexia, reading disability, difficulty reading, phoneme, visual sequential memory, reading comprehension, attention-deficit hyperactivity disorder, ADHD, Orton-Gillingham method, Lindamood-Bell method INTRODUCTIONSection 2 of 10
  The first description of a specific reading disability was an 1896 case study in the British medical literature of a "bright and intelligent boy" who had great difficulty learning to read. The paradox of dyslexia causes some intelligent people to have persistent and extreme difficulty in reading and has intrigued educators for more than 100 years. Dyslexia is traditionally defined as an unexpected difficulty learning to read despite intelligence, motivation, and educational opportunities. VISUAL PERCEPTUAL PROBLEMSSection 3 of 10
At the beginning of the 20th century, dyslexia was believed to be caused by defects in the visual processing system that reversed and transposed words and letters. Prescriptions to overcome these visual defects involved eye training and other training to improve visual perception of written letters and words. This view of dyslexia persists despite research over the past 30 years that clearly shows children with dyslexia are not unusually prone to reversing letters or words. Furthermore, eye training—in all its variations, whether practiced by teachers, optometrists, or occupational therapists—has not proven effective in treating reading problems.1 PHONETIC PROCESSINGSection 4 of 10
Psychological, educational, and brain research over the past 20 years has consistently shown that dyslexia is a disorder related to the language system. Dyslexia involves deficient processing of individual linguistic units, called phonemes, which comprise all spoken and written words. A phoneme is defined as the smallest detectable sound of a word of a language; a morpheme is the smallest meaningful speech sounds. Phonemes and morphemes are the fundamental elements of the linguistic system, and phonemes are critically important for the acquisition of spoken and written language. For example, in English, the word cat is comprised of 3 phonemes: "kuh,” “aah," and "tuh." Phonological processing areas in the brain must break down or segment words into phonemic units before an individual can identify, understand, store, or remember them. In spoken language, this process occurs automatically, without the speaker or listener consciously processing the information. Speech requires blending the phonemes automatically into complete words, and, thus, words appear to the ear as seamless, with no breaks. Although the word cat may appear as a single sound, humans can segment it into the 3 component phonemes. Research has shown that reading directly reflects spoken language. The process of reading involves the perception of alphabetic script coded as phonemes (ie, each symbol represents a phoneme). To read, a person must first recognize that the visual sequence of letters appears in a specific order and that this sequence represents phonology, or the sound of the letters. To learn to read, an individual must be able to simultaneously segment the letters into sounds and then blend those sounds into words. This process must occur fast enough for reading fluency, and the reader must also remember and retain the words read long enough to associate meanings with the sentences or paragraphs that are read. Slow phoneme processing appears to be the primary cause of reading problems. Poor ability in any part of this process (eg, segmenting/blending, speed, memory) adversely affects overall reading ability. A child with dyslexia typically has problems with segmentation, the process of recognizing different phonemes that constitute words or with blending these sounds to make words. A problem with speed or with rapidly naming words or letters interrupts reading fluency. Additionally, visual sequential memory problems interfere with reading comprehension. NEUROPHYSIOLOGYSection 5 of 10
Genetic and neurobiological research confirms psychological research in this area. Family studies show that a reading disorder is heritable, is found in clusters in families, and probably reflects autosomal dominant transmission. Neurologically, positron emission tomography (PET) scan studies suggest that phonological defects in reading strongly relate to decreased activity in the left perisylvian region, including the superior and medial temporal gyri. Additional functional imaging work indicates that anterior regions of the brain are activated during phonological or rhyming tasks. In addition, the left temporo-occipital region, which is active during the automatic perception and processing of visually presented words in skilled readers, is also implicated in reading problems. A lack of word-specific responsiveness in this region is found in adults with reading impairment. Anatomical lesion analysis has shown that this region is necessary for rapid perception of word forms. The most prominent current hypothesis about the relationship between these 2 regions of phonological and visual processing is that atypical phonological processing in the prereading years leads to inefficient mapping during early reading. Thus, the atypical phonological processing disrupts the development of the functional specialization of the visual areas. The brains of individuals with reading disorders are organized somewhat differently and appear to process the phonological information in a less efficient, more diffuse manner. FREQUENCYSection 6 of 10
Data from epidemiological studies indicate as many as 40% of all early elementary school students in the Reading disorder rates show no racial differences. For approximately the past 30 years, public schools have included the intelligence quotient (IQ) as part of their assessment for severe reading problems. Administratively, a learning disability was defined as a significant discrepancy between the IQ and the reading achievement score. For example, if a child has an average IQ (100) and a lower reading score on a standard test (75), that would be considered a reading discrepancy. However, this works against children with below-average IQ scores. African American children who are referred for reading problems score about 7 points lower on IQ tests, are more likely to be classified as having mild mental retardation, and are less likely to be classified as having a reading disability. In contrast, similarly referred white or Asian children are more likely to be labeled as learning disabled. However, the 2004 version of the federal Individuals with Disabilities Education Act (IDEA) no longer requires states to use the discrepancy score criteria (eg, if the IQ is 20 points higher than the reading achievement score, the discrepancy is significant) to identify reading disabilities. All that is now required to identify a learning disability is a significant delay and a poor response to a reading intervention. How each state interprets this law in the public school is still being developed. Because states develop their own rules, some states may retain the discrepancy criteria. Boys are 3-4 times more likely to be referred for reading problems, although epidemiological studies show equal numbers of girls and boys are poor readers. CLINICAL EVALUATIONSection 7 of 10
History Delayed early language development, difficulty segmenting words or recognizing the differences between similar sounds, and a family history of reading disability all indicate a potential learning problem. Tests Children with normal reading processes spontaneously begin to decode and segment words at age 4-6 years. The most reliable indicator of a reading difficulty is the inability to decode single words. The 3 components of phonological processing that predict reading ability are (1) awareness of different phonemes (eg, ability to follow instructions such as pronouncing cup without the /k/ sound), (2) ability to name objects, letters, or numbers quickly, and (3) working memory (ie, ability to accurately repeat sentences, words, or strings of numbers). Although assessment of intellectual ability, IQ, and achievement level is included in a standard school assessment of reading, these data are unreliable predictors of overall reading ability. Phonological processing ability is the best predictor of reading. TREATMENTSection 8 of 10
Medical care No medical care is indicated for reading disorders. Appropriate referrals to a special education (SPED) setting, specialized tutoring setting, or both can prove important for long-term progress. School consultations The 2004 IDEA requires public schools to provide free and appropriate evaluations and education for children with learning disabilities. Because as many as 20% of all children may have phonologically based reading problems, not all children are evaluated by the school. If a parent or health care provider suspects a significant reading problem, the parent should make a formal request (ie, a dated letter) for evaluation to the school and request to develop an appropriate individual education plan (IEP). With parental permission, a second letter from a health care provider requesting the evaluation often helps; however, the parent must make the initial request. Although state and local school district regulations differ, most districts must comply with a request for evaluation within 60 school days. SPED services provided for a child with a reading disability typically include some time each day in a small group with a reading specialist. The child spends the remainder of the day in a standard classroom. In addition to SPED, many elementary schools also offer the Title I enhanced reading program, which is designed to address the reading needs of economically disadvantaged children. In schools that offer the Title I program, a parental request for those services is often the sole requirement. No formal assessment is required for participation in Title I, although assessment might help some children. In many school districts, all reading programs in kindergarten and first and second grades are administered through the Title I mechanism; SPED is reserved for reading problems in the higher grades. Intervention strategies
Some schools do not emphasize these processes. The only option for children in these schools is to find an appropriate reading tutor or after-school reading programs. Programs that use the Orton-Gillingham or Lindamood-Bell methods have some success teaching students with reading disorders. Both systems emphasize sound recognition and sound-symbol relationships as the basis for reading. Parents should evaluate private reading clinics and should also inquire about reading clinics offered by local colleges of education. Helpful software programs are also available to teach phonemic recognition; programs such as Reader Rabbit or Blues Clues can be effective adjuncts to tutoring and classroom intervention. Medication For children with ADHD, appropriate stimulant treatment is indicated; otherwise, no medical treatment is suggested for reading problems. PROGNOSISSection 9 of 10
Although parents assume that intervention will help their child catch up with peers, this notion is unsubstantiated by research data. In a Yale longitudinal study, persistently poor readers (ie, children identified in the early grades by their poor phonemic processing) continued to read more poorly than their nondisabled peers.3 Although these children did learn to read, they continued to lag significantly behind peers throughout high school in decoding, reading rate, and accuracy. Despite poor scores in these areas, their overall reading comprehension scores were only mildly delayed. With persistent intervention and considerable personal effort, these children can achieve an adequate literacy level to function in society, although their reading abilities may still lag behind the skills of their peers. Comorbidities A widespread dilemma for physicians is when a child is failing in school and is suspected of having a reading disability, yet the school suspects the child has ADHD. Often, both educators and physicians delay evaluations and diagnosis while awaiting results from the other discipline. Although ADHD and a reading disorder are perceived as independent, significant overlap is observed.2 In nonreferred epidemiological studies, children with a reading disorder are twice as likely as other children to have ADHD; the rate of such dual incidence approaches 15%. Conversely, individuals diagnosed with ADHD are also twice as likely to have phonological awareness problems directly related to a reading disorder; 36% of patients with ADHD have this difficulty. Comorbidity rates in clinically referred samples are higher, approaching 40% for both groups. Social maladjustment is also more common in children with a reading disorder. Prevalence rates of anxiety, withdrawal, and depression are much higher than in peers without this disorder. Social problems become more pronounced as children age because they fall further behind in reading skills and in other subjects that require reading ability. Most children who have severe oppositional and conduct disorders have significant reading problems, which are often overlooked as school personnel attempt to cope with the conduct problems. Children rarely have a single learning disability. Multiple learning disabilities can be expected because reading, spelling, listening, speaking, and writing all involve manipulations of the same linguistic system. Children who have difficulty with reading typically have difficulty with spelling. These difficulties are quite frustrating to parents and students. Parents commonly report working on spelling lists for hours to perfect performance the night before a test, only to have the child fail the test the next morning. Logically, children who have difficulty spelling single words also have difficulty organizing and expressing more complex thoughts in writing. These children also tend to have difficulty with grammar and syntax. Difficulties become more pronounced in higher grades as instructors place more emphasis on written explanations. REFERENCESSection 10 of 10
Learning Disorder: Reading excerpt Article Last Updated: Feb 25, 2008 |
