Cognitive Profiles And Fatty Acid Metabolism Of Chinese Children With Developmental Dyslexia

Developmental dyslexia is marked by reading achievement that falls substantially below that expected given the individual's chronological age, measured intelligence, and age-appropriate education. Dyslexia is fairly widespread but with uncertain prevalence, ranging from 5% to 10%, it is the most common of the childhood learning disorders. The theories of dyslexia can be grouped within two opposed frameworks. One is linguist theory and another is sensorimotor theory especially. The debate on phonological processing and visual-spatial cognition of dyslexia is a hot topic in the research area of dyslexia. Developmental dyslexia is a problem not only with alphabetic readers, but also with nonalphabetic readers. Different from any alphabetic language, Chinese is a deep orthography used by a very large population in the world. The logographic nature of Chinese and the great number of visually distinct and complicated Chinese characters have led many people to think that visual skills are important in learning to read Chinese. Some studies did show that visual skills were related to Chinese children's reading performance. The history of Chinese developmental dyslexia research is very short. The role of visual factors in Chinese developmental dyslexia is also controversial. There is increasing evidence that functional deficiencies or imbalances of omega-3 and omega-6 highly unsaturated fatty acids (HUFA) may play a role in dyslexia. However, data on the biochemistry of Chinese developmental dyslexia is still scarce. In the present study, we discussed the cognitive profiles and fatty acid metabolism of Chinese developmental dyslexia using investigative research, cognitional research and biochemistry teat to provide the reading feature of this disorder and lay academic foundations for diagnosis, and intervention of Chinese dyslexics. PartⅠReading Features of Chinese Children with Developmental DyslexiaObjective To explore the reading feature and subtype of Chinese children with developmental dyslexia.Methods 820 children in 3 primary schools in Wuhan City were selected by cluster sampling. 55 children with developmental dyslexia were chose according to ICD-10. And 110 normal children with the same age, sex and socioeconomic status were chose as control. The questionnaires included PRS (The Pupil Rating Scale Revised Screening for Learning Disabilities), DCCC (Dyslexia Checklist for Chinese Children) and WISC-CR (Wechsler Intelligence Scale for Children- Chinese Revision) were applied to investigate and collect data.Results There were 55 children being found to be dyslexics and the prevalence rate of developmental dyslexia is 6.7%. The prevalence rate of boys was higher than that of girls (P<0.01). The score of 8 items of DCCC of developmental dyslexics were mostly significantly higher than that of normal children. The conditional logistic analysis suggested that auditory perception can significant explain the developmental dyslexia (OR=2.00). There was significant sex difference of the DCCC score in control group. But there was no significant sex difference in dyslexic group expect for spoken language. The DCCC score at the 3rd grade was the highest among three grades. The DCCC score with dyslexics at the 5th grade was obviously higher than normal children at the 3rd grade (P<0.05) expect for spoken language. The main disorder subtype was auditory perception disorder, Bad reading custom and written expression disorder.Conclusion Since the number of Chinese dyslexic children was not low, parents and teachers should pay more attention to them. The impairment involved all processes of reading in children with Chinese developmental dyslexia, and the main problem was auditory perception disorder. It suggested that there maybe exist phonological awareness deficits and disability of phonological processing in Chinese children with dyslexia. Chinese developmental dyslexia was a"developmental deficits"to some extent. PartⅡCognitive Profiles of Chinese Children with Developmental DyslexiaSectionⅠEffects of the Intelligence of Chinese Children with Developmental DyslexiaObjective To compare intelligence of children with developmental dyslexia with that of normal and try to find the effects of intelligence structure on developmental dyslexia.Methods According to ICD-10 criteria, 55 children diagnosed as dyslexia, a control group including 55 normal children was matched by gender, age, parental education levels, occupations and economic status and collected according to the rate of 1: 1. CRT-C2 (Combined Raven's test in China Revision 2) was applied to both groups. And the intelligence effects on developmental dyslexia were explored by conditional univariate and multivariate logistic regression analysis.Results The intelligence quotients of the case and the control were 106.56±13.12 and 117.16±14.09, and were both on the normal level. Majority dyslexia children (58.1%) were with common IQ level or below. However, majority control children (70.9%) were with excellent IQ or above. The children's intelligence distribution of the dyslexia children was different significantly (P<0.01). The dyslexic children had significantly lower IQ scores and subset scores than those of control group (P<0.05). The score of IQ, especially that of perceptive discernment and analogical comparison, was significant correlated with the severity of dyslexic signs and symptoms (the score of CDDD) in dyslexia group (P<0.05). With the multiple logistic regression analysis, only the analogy ability entered the regression model (P<0.01, OR=0.673, OR95.0%CI: 0.503-0.902). The analogy ability was a protective factor.Conclusion The dyslexic children have multiple cognitive deficiencies in analog, analysis and abstract abilities. It suggested that we may focus on the direct observation abilities training with children to promote their reading abilities. SectionⅡPhonological Processing Ability of Chinese Children with Developmental DyslexiaObjective In order to explore the phonological processing ability with Chinese developmental dyslexia children.Methods 53 dyslexic children were chosen according to ICD-10, and control group was matched by gender, age, parental education levels, occupations and economic status and collected according to the rate of 1: 1. All subjects were asked to accomplish the phonological recognizing tasks including initial phoneme and final phoneme of Chinese syllable. Correct number and average response time with phonological processing tasks were compared between dyslexic group and control group. And predictability of phonological processing abilities on developmental dyslexia was explored by multiple conditional logistic regression analysis.Results The correct number of initial phoneme and final phoneme recognizing of a Chinese syllable with dyslexic children was less than that of control group (P<0.05). Dyslexic children need more response time than that of control group when they did the task, but the difference did not reach significant (P>0.05). Significant negative correlations were found between the correct number of phonological tasks and the score of all factors of DCCC (P<0.05) both in the whole sample and in control group (P<0.05). However, the negative correlation did not reach significant expect for that with auditory/language, attention and total score of DCCC in dyslexic group (P<0.05). The correct number of initial phoneme recognizing was a protect factor of developmental dyslexia (P<0.01, OR=0.001, OR95.0%CI: 0.000-0.177).Conclusions Chinese dyslexic children exist phonological processing deficits,just like the peers of alphabetic languages.Phonological processing deficits may be one of the causes for dyslexia. But correlation between phonological processing abilities and reading abilities in dyslexia was not obvious and the predictability of the phonological processing abilities on developmental dyslexia was week, the role of phonological awareness on developmental need further explore. SectionⅢVisual Processing Ability of Chinese Children with Developmental DyslexiaObjective In order to explore the visual processing ability including figure and Chinese character visual processing with Chinese developmental dyslexia children.Methods 53 dyslexic children were chosen according to ICD-10, and control group was matched by gender, age, parental education levels, occupations and economic status and collected according to the rate of 1: 1. On the basis of the feature of Chinese character, we designed some figure visual processing tasks according to the principle of the Raven's Progressive Matrices test, the Visual Form Discrimination test and the Gardner's test of Visual Perceptual Skills and some Chinese character visual processing tasks. All subjects were asked to accomplish the visual processing tasks. Correct number and average response time with visual processing tasks were compared between dyslexic group and control group. And predictability of visual processing abilities on developmental dyslexia was explored by multiple conditional logistic regression analysis.Results both with figure visual processing tasks and Chinese character visual processing tasks, there were no significant differences (P>0.05) between dyslexic group and control group on correct number and the average response time. Correlation between the right number of visual processing tasks and the score of all factors of DCCC did not reach significant expect for that with attention and total score of DCCC in the whole sample (P<0.05). The correlation did not reach significant in dyslexic group and control group (P>0.05).Conclusions There was not obvious effect on reading abilities with Chinese children by visual processing abilities. Visual processing abilities were probably not a sufficient condition but an essential condition on Chinese character discrimination. PartⅢFatty Acid Metabolism Feature of Chinese Children with Developmental DyslexiaSectionⅠRelationship between Fatty Acid Deficiency Signs and Reading Difficulties of Chinese Children with Developmental DyslexicObjective To explore the relationship between fatty acid deficiency and reading developmental dyslexia in Chinese children.Methods 53 dyslexic children were chosen according to ICD-10 and 104 normal children was matched by gender, age, parental education levels, occupations and economic status and collected chosen according to the rate of 1: 2. All subjects were investigated by two parent-report questionnaires: clinical signs of fatty acid deficiency and symptoms associated with dyslexia (CDDD).Results Total FADs were found to be highly significantly higher in the dyslexics (P<0.01). Subdivision of the sample by sex revealed that there were significant differences between total FADS scores for dyslexic and control subjects within males and females (P<0.05). 33 of the 52 dyslexia children (63.46%) but only 40 of 104 normal children (38.46%) had total FADS scores>3. This difference reaches significance (χ2=8.702, P =0.003). In the whole sample, significant correlations were found between FADS and all factors of DCCC (P<0.001). In control group, significant correlations were found between FADS and all factors of DCCC (P<0.001). Male controls showed all significant correlations. In female controls, scores on FADS were significantly correlated with all factors of CDDD except for that with spoken language problems. In dyslexic group, all the associations were significant (P<0.05) except for that with spoken language problems, disorder of written expression and bad reading custom. In dyslexic males FADS correlate significantly only with the auditory/language problems, writing disturbance and attention disorder of CDDD (P<0.05). Dyslexic females' scores on FADS were significantly correlated with writing disturbance and spoken language problems. It was notable that the correlations between FADS and visual problems, auditory/language problems, understanding disturbance and attention disorders were in the opposite direction although it didn't reach significant. It was found that excessive thirst, dry skin and follicular keratosis were risk factors on developmental dyslexia by multiple condition logistic regression analysis.Conclusion Fatty acid deficiency signs were significantly elevated in dyslexic subjects relative to control. The severity of these clinical signs of fatty acid deficiency was correlated with the severity of dyslexic signs and symptoms not only in the visual domain, but also with respect to spoken language and attention problems. Our findings support the hypothesis that fatty acid metabolism may be abnormal in developmental dyslexia, and indicate the need for further studies using more objective measures.SectionⅡBlood Fatty Acid Composition in Chinese Children with Developmental DyslexiaObjective Analysis the blood fatty acid composition in Chinese children with developmental dyslexia to explore the role of fatty acid in Chinese children with developmental dyslexia.Methods 5 dyslexic children were chosen according to ICD-10 and 5 normal children was matched by gender, age, parental education levels, occupations and economic status and collected chosen according to the rate of 1: 1. Gas Chromatogram (GC) was adopted to analyze plasma fatty acid composition and red blood cell (RBC) membranes.Results There were no significant differences between the dyslexic and control group both on any of the plasma fatty acid measures and any of the RBC fatty acid measures(P>0.05). There were strong correlation between plasma fatty acid composition especially total omega-3 concentrations and reading abilities.Conclusion Our results suggest that there were no differences in fatty acid levels between the dyslexic and control subjects. And our results showed that omega-3 status was directly related to reading performance both in dyslexic and control group.