OBJECTIVE: To study the intellectual characteristics of children with attention deficit hyperactivity disorder (ADHD) and developmental dyslexia (DD). METHODS: A total of 55 children with ADHD and DD (ADHD+DD group), 150 children with ADHD alone (ADHD group), and 22 children with DD alone (DD group) were enrolled as subjects. Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV) was used to evaluate and compare intellectual characteristics among the three groups. RESULTS: There were significant differences in the scores of full-scale intelligence quotient (FSIQ), verbal comprehension index, perceptual reasoning index, and working memory index among the three groups ( CONCLUSIONS Compared with the children with ADHD alone, the children with ADHD and DD have more severe impairment of FSIQ, verbal comprehension, perceptual reasoning, and working memory, and therefore, it is suggested to enhance the training on similarities, vocabulary, matrix reasoning, picture concepts, and recitation for children with ADHD and DD in clinical practice.
Attention Deficit Disorder with Hyperactivity ; Child ; Dyslexia ; Humans ; Intelligence Tests ; Memory, Short-Term ; Wechsler Scales

Introduction: Teachers play a vital role in identifying students with dyslexia. The acquisition of this knowledge will help teachers to classify students who are at risk of dyslexia. The objective of this study is to identify the level of teachers’ knowledge about dyslexia that comprises of its general knowledge, diagnosis, symptoms and treatments. A cross sectional study was done upon 138 preschool teachers. This research was conducted by using ‘Knowledge and Beliefs about Developmental Dyslexia’ questionnaire, which consists of 36 items with 3 Likert scale questions. Findings revealed that the level of general knowledge possessed by the pre-school teachers was relatively different based on the construct even though they have respectively received the Diploma in Early Childhood Education. On the same hand, most of the respondents were found to be having higher understanding on the general knowledge about dyslexia compared to their understanding on the symptoms, diagnosis and the treatments
Dyslexia

OBJECTIVES: To compare the white matter microstructure of dyslexic children with normal children using diffusion tensor imaging. METHODS: Twenty one dyslexic children and 24 normal control children were recruited in the second and third grade of elementary school students. The fractional anisotropy (FA) values of 20 representative white matter tracts were estimated from the diffusion tensor imaging data of each subject using the Johns Hopkins University-white matter tractography atlas to determine the difference in white matter integrity between the dyslexic children and normal children. RESULTS: Compared to the normal control group, the FA values of the left inferior longitudinal fasciculus [F(1,39)=5.908, p<0.05] and temporal part of the right superior longitudinal fasciculus [F(1,39)=7.328, p=0.010] were significantly higher in the dyslexic group and there was no significant difference in the other tracts. CONCLUSION: In dyslexic children, compensatory pathways develop in the left inferior longitudinal fasciculus and in the temporal part of the right superior longitudinal fasciculus.
Anisotropy ; Case-Control Studies ; Child ; Diffusion Tensor Imaging ; Dyslexia ; Humans ; White Matter

OBJECTIVETo explore the abilities of verbal and visual-spatial memory in Chinese children with developmental dyslexia.

METHODSThirty-two children with developmental dyslexia (aged 8-12 years) and thirty-nine age- and gender-matched normal children were involved in the study. Their verbal short-term and verbal working memories were measured using the digit ordering and the digit span tests, respectively. Their visual-spatial short-term and visual-spatial working memories were examined using the forward and backward block-tapping tests, respectively.

RESULTSThe DD children scored lower in the digit ordering and the digit span tests than the control children (P<0.05). The scores for the forward and backward block-tapping tests did not vary between the two groups (P>0.05).

CONCLUSIONSThe children with DD have the deficits in both verbal short-term memory and verbal working memory.

OBJECTIVES: This study investigated the prevalence of reading and mathematical learning disabilities of students at primary schools in Jeju Island, South Korea. We examined major causes of learning disabilities including reading disorder, mathematical disorder, attention deficit, and other causes including socioemotional factors. METHODS: We conducted screening processes to 659 participants (340 male, 51%) in 4 elementary schools in Jeju Island. To identify the causes of learning problems, 84 children were administered tests such as the Korean-Wechsler Intelligence Scale for Children-fourth edition, the Comprehensive Learning Test-Reading/Math, and the Comprehensive Attention Test. RESULTS: This study found that 13% of elementary school students in the Jeju region had learning disabilities. Among learning disabilities, specific reading and mathematical disorders accounted for 9% of study subjects. In addition, 2% of participants had intellectual impairment and 1% had other causes such as socioemotional factors. 65% of children with learning disabilities and 74% of children with reading or mathematic disorders had concurrent attention deficit disorder. 68% of children with reading disorders also had comorbid mathematical disorder. CONCLUSION: The prevalence, causes, and comorbidity of reading and mathematical learning disabilities of students in Jeju Island, South Korea did not differ from those in foreign countries. Because most learning disabilities are complex, comprehensive evaluations and tailored interventions are necessary to help children with learning disabilities.
Attention Deficit Disorder with Hyperactivity ; Child* ; Comorbidity ; Dyscalculia ; Dyslexia ; Epidemiology ; Humans ; Intelligence ; Korea ; Learning Disorders* ; Learning* ; Male ; Mass Screening ; Mathematics ; Prevalence*

Children with Specific Learning Disorder (SLD) faces challenges in academic areas and are often negatively labelled. The learning problems in SLD children were mainly due to poor phonological skill but not much was known about the contribution of visuospatial difficulties. Therefore, this study aims to determine the relationship between phonological awareness skills and global visual-spatial abilities among Malay speaking children with SLD, and to compare children with SLD and typical readers on intellectual functioning, phonological awareness and global visual-spatial ability. An equal number of typical readers (n = 36) and children with SLD were recruited. Data were coded and analysed using Kendall’s Tau-b, independent samples t-test and Mann-Whitney U test. Results showed phonological skills have strong negative correlation with global visual-spatial ability (r = .55). The typical readers have significantly higher IQ and better phonological skills and better global visual-spatial skills as compared to the group with SLD. However, there is no conclusive evidence due to specificity of more than one area measured by the assessment tools. Nevertheless, it provides a direction for future research to look into global visual-spatial aspects of SLD to aid in educational instruction in the future, in addition to the long-standing phonology deficit theory.
Specific Learning Disorders ; dyslexia ; phonological awareness, global visual-spatial ability, intellectual functioning

OBJECTIVE: Individuals with dyslexia experience reading difficulties, whereas their other cognitive abilities seem normal. The purpose of this study was to investigate the event-related potential (ERP) patterns of children with dyslexia during a target-detection task. METHODS: Seventeen children with dyslexia and 18 children without this disorder participated in this study. We evaluated their writing and reading ability, symptoms of attention-deficit/hyperactivity disorder, and intelligence quotient. ERPs were recorded while participants performed a target-detection task, and the peak amplitude and latency of P100 and P300 were analyzed. The lateral asymmetry index (LAI) was calculated for each ERP component. RESULTS: The dyslexic group exhibited longer reaction times and larger P100 amplitudes than the non-dyslexic group in the right hemisphere. The P100 latency was also significantly delayed in the right hemisphere of those in the dyslexic group compared with those in the non-dyslexic group. The P300 amplitude was larger in the right hemisphere compared with left hemisphere in the dyslexic group, whereas no interhemispheric differences were observed with respect to the P300 latency. The LAI for P100 showed a significant right hemispheric dominance, whereas the LAI for P100 was significantly correlated with the accuracy of target detection in children with dyslexia. CONCLUSION: Our results suggest that right hemispheric dominance acts as an ancillary system that compensates for poor reading in children with dyslexia.
Child* ; Dyslexia* ; Evoked Potentials* ; Humans ; Intelligence ; Reaction Time ; Reading ; Writing

OBJECTIVES: The aim of this study was to develop the computerized Comprehensive Learning Test-Reading (CLT-R) to evaluate the cognitive processes and achievements related to their basic reading ability and identify dyslexia in children and adolescents in South Korea. We also obtained the normative data and evaluated the reliability and validity of the test. METHODS: We developed the CLT-R, including the word attack/nonword decoding, paragraph reading, sound blending, nonword repetition, rapid automatized naming, letter-sound matching, visual attention, orthography awareness, and digit span tests, for the purpose of diagnosing dyslexia. We investigated the reliability and validity of the tests and gathered the normative data from 399 subjects (male 48.9%), aged 5-14 years, from the last grade in kindergarten to middle school, dwelling in Seoul and Gyeonggi Province, South Korea. RESULTS: No statistical differences were observed between the means of the tests and retests of the CAT. The mean of the correlation coefficient of the test-retest scores was 0.85. According to the construct validity test calculated by principal constant analysis using the oblique rotation method, 4 factors explained 70.0% of the cumulative variances. In addition, the normative data were obtained for all of the CLT-R subtests. CONCLUSION: The computerized CLT-R can be used as a reliable and valid tool to evaluate the reading achievement and reading related cognitive process in Korean children and adolescents in schools, clinics, and research institutes.
Academies and Institutes ; Adolescent* ; Animals ; Cats ; Child* ; Diagnosis* ; Dyslexia* ; Gyeonggi-do ; Humans ; Korea ; Learning* ; Methods ; Reading ; Reproducibility of Results ; Seoul

BACKGROUND: Korean orthography is composed of Hanja (ideograms) and Hangul (phonograms). Based on previous studies, the fusiform gyrus has been associated with ideogram reading. We examine serial functional magnetic resonance imaging (fMRI) images in a patient exhibiting dissociation of Hanja and Hangul reading to identify brain areas associated with Hanja reading. CASE REPORT: fMRI were taken of a 63-year-old man showing profound Hanja alexia with normal Hangul reading after an acute stroke involving the left frontal and parietal lobes, who later spontaneously recovered his Hanja reading ability. Scans were taken while performing Hanja and Hangul reading tasks on three occasions. As a result, in spite of having profound Hanja alexia, partial activation of the fusiform gyrus was observed on the first fMRI. Serial fMRI scans showed activation of the bilateral middle frontal gyri that increased in parallel with the patient's recovery of Hanja reading. CONCLUSIONS: The frontal lobe, not only fusiform gyrus, may play role in reading Hanja, although more evidence is needed.
Brain ; Dyslexia* ; Frontal Lobe ; Humans ; Magnetic Resonance Imaging* ; Middle Aged ; Parietal Lobe ; Reading ; Stroke* ; Temporal Lobe*

Developmental dyslexia in children is one of the neurodevelopmental disorders and is affected by various susceptible genes. In recent years, researchers have found some susceptible genes for dyslexia via chromosome analysis, genome-wide association studies, association analysis, gene function research, neuroimaging, and neurophysiological techniques. This article reviews the research advances in susceptible genes for developmental dyslexia, and with the study on susceptible genes for dyslexia, it lays a foundation for in-depth studies on the "gene-brain-behavior" level and provides scientific clues for exploring etiology and pathogenesis of dyslexia.
Child ; Dyslexia ; genetics ; Forkhead Transcription Factors ; genetics ; Genetic Predisposition to Disease ; Humans ; Microtubule-Associated Proteins ; genetics ; Nerve Tissue Proteins ; genetics ; Nuclear Proteins ; genetics ; Receptors, Immunologic ; genetics