The Prevalence of Thyroid Autoimmunity in Children with Developmental Dyslexia.

METHODS: We enrolled pediatric subjects with developmental dyslexia and, as a control group, healthy age- and sex-matched subjects without developmental dyslexia. Thyroid function was evaluated in subjects with developmental dyslexia measuring serum concentrations of thyroid-stimulating hormone (TSH), free triiodothyronine (fT3), and free thyroxine (fT4). Thyroid autoimmunity was evaluated in all subjects measuring antithyroid peroxidase (TPO-Ab) and antithyroglobulin (TG-Ab) antibodies. In subjects with developmental dyslexia, thyroid ultrasonography (US) was also performed. RESULTS: We enrolled 51 subjects with developmental dyslexia (M : F = 39 : 12, mean age 12.4 ± 9 years) and 34 controls (M : F = 24 : 10, mean age 10.8 ± 4 years). TPO-Ab positivity was significantly higher in subjects with developmental dyslexia compared to controls (60.8% vs. 2.9%, p < 0.001), while no significant difference was found in TG-Ab positivity (16% vs. 5.8%). Thyroid US performed in 49 subjects with developmental dyslexia revealed a thyroiditis pattern in 60%. CONCLUSIONS: We found an extremely high prevalence of thyroid autoimmunity in children with developmental dyslexia. Further studies are needed to confirm our observations, but our findings may change the approach to this disorder and eventually lead to a systematic determination of thyroid autoimmunity in children with developmental dyslexia.

Identifying Dyslexia Risk in Student-Athletes: A Preliminary Protocol for Concussion Management.

Learning disability (LD) has been identified as a potential risk factor for a sport-related concussion, yet students with LD are rarely included in concussion research. Here, we draw special attention to dyslexia, a common but often underdiagnosed LD. Reading and learning problems commonly associated with dyslexia are often masked by protective factors, such as high verbal ability or general intelligence. Hence, high-achieving individuals with dyslexia may not be identified as being in a high-risk category. To ensure that students with dyslexia are included in LD concussion research and identified as LD in baseline testing, we provide athletic trainers with an overview of dyslexia and a preliminary screening protocol that is sensitive to dyslexia, even among academically high-achieving students in secondary school and college.

Normal radial migration and lamination are maintained in dyslexia-susceptibility candidate gene homolog Kiaa0319 knockout mice.

Developmental dyslexia is a common disorder with a strong genetic component, but the underlying molecular mechanisms are still unknown. Several candidate dyslexia-susceptibility genes, including KIAA0319, DYX1C1, and DCDC2, have been identified in humans. RNA interference experiments targeting these genes in rat embryos have shown impairments in neuronal migration, suggesting that defects in radial cortical migration could be involved in the disease mechanism of dyslexia. Here we present the first characterisation of a Kiaa0319 knockout mouse line. Animals lacking KIAA0319 protein do not show anatomical abnormalities in any of the layered structures of the brain. Neurogenesis and radial migration of cortical projection neurons are not altered, and the intrinsic electrophysiological properties of Kiaa0319-deficient neurons do not differ from those of wild-type neurons. Kiaa0319 overexpression in cortex delays radial migration, but does not affect final neuronal position. However, knockout animals show subtle differences suggesting possible alterations in anxiety-related behaviour and in sensorimotor gating. Our results do not reveal a migration disorder in the mouse model, adding to the body of evidence available for Dcdc2 and Dyx1c1 that, unlike in the rat in utero knockdown models, the dyslexia-susceptibility candidate mouse homolog genes do not play an evident role in neuronal migration. However, KIAA0319 protein expression seems to be restricted to the brain, not only in early developmental stages but also in adult mice, indicative of a role of this protein in brain function. The constitutive and conditional knockout lines reported here will be useful tools for further functional analyses of Kiaa0319.

Language impairment and dyslexia genes influence language skills in children with autism spectrum disorders.

Language and communication development is a complex process influenced by numerous environmental and genetic factors. Many neurodevelopment disorders include deficits in language and communication skills in their diagnostic criteria, including autism spectrum disorders (ASD), language impairment (LI), and dyslexia. These disorders are polygenic and complex with a significant genetic component contributing to each. The similarity of language phenotypes and comorbidity of these disorders suggest that they may share genetic contributors. To test this, we examined the association of genes previously implicated in dyslexia, LI, and/or language-related traits with language skills in children with ASD. We used genetic and language data collected in the Autism Genome Research Exchange (AGRE) and Simons Simplex Collection (SSC) cohorts to perform a meta-analysis on performance on a receptive vocabulary task. There were associations with LI risk gene ATP2C2 and dyslexia risk gene MRPL19. Additionally, we found suggestive evidence of association with CMIP, GCFC2, KIAA0319L, the DYX2 locus (ACOT13, GPLD1, and FAM65B), and DRD2. Our results show that LI and dyslexia genes also contribute to language traits in children with ASD. These associations add to the growing literature of generalist genes that contribute to multiple related neurobehavioral traits. Future studies should examine whether other genetic contributors may be shared among these disorders and how risk variants interact with each other and the environment to modify clinical presentations.

Neocortical disruption and behavioral impairments in rats following in utero RNAi of candidate dyslexia risk gene Kiaa0319.

Within the last decade several genes have been identified as candidate risk genes for developmental dyslexia. Recent research using animal models and embryonic RNA interference (RNAi) has shown that a subset of the candidate dyslexia risk genes--DYX1C1, ROBO1, DCDC2, KIAA0319--regulate critical parameters of neocortical development, such as neuronal migration. For example, embryonic disruption of the rodent homolog of DYX1C1 disrupts neuronal migration and produces deficits in rapid auditory processing (RAP) and working memory--phenotypes that have been reported to be associated with developmental dyslexia. In the current study we used a modified prepulse inhibition paradigm to assess acoustic discrimination abilities of male Wistar rats following in utero RNA interference targeting Kiaa0319. We also assessed spatial learning and working memory using a Morris water maze (MWM) and a radial arm water maze. We found that embryonic interference with this gene resulted in disrupted migration of neocortical neurons leading to formation of heterotopia in white matter, and to formation of hippocampal dysplasia in a subset of animals. These animals displayed deficits in processing complex acoustic stimuli, and those with hippocampal malformations exhibited impaired spatial learning abilities. No significant impairment in working memory was detected in the Kiaa0319 RNAi treated animals. Taken together, these results suggest that Kiaa0319 plays a role in neuronal migration during embryonic development, and that early interference with this gene results in an array of behavioral deficits including impairments in rapid auditory processing and simple spatial learning.

Transtorno do processamento auditivo (central) em indivíduos com e sem dislexia / (Central) auditory processing disorders in individuals with and without dyslexia

TEMA: comparação do transtorno do processamento auditivo (central) em indivíduos com e sem dislexia. OBJETIVO: comparar o transtorno do processamento auditivo (central) em crianças brasileiras com e sem dislexia, por meio dos testes fala com ruído, dicótico de dígitos e padrão de freqüência. MÉTODO: foram avaliadas 40 crianças de 7:0 a 12:11 anos, sendo 20 pertencentes ao grupo com dislexia e 20 pertencentes ao grupo TPA(C). Os testes aplicados envolveram habilidades de fechamento auditivo, figura-fundo para sons lingüísticos e ordenação temporal. RESULTADOS: os indivíduos do grupo TPA (C) apresentaram maior probabilidade de alteração nos testes de fala com ruído e dicótico de dígitos do que os pertencentes ao grupo dislexia. CONCLUSÃO: os sujeitos do grupo dislexia apresentam padrões diferentes de transtorno de processamento auditivo (central), com alteração maior em testes que avaliam o processamento temporal do que em testes que avaliam outras habilidades auditivas.

BACKGROUND: comparison of (central) auditory processing disorders in children with and without dyslexia. AIM: to compare the (central) auditory processing disorders in Brazilian children with and without dyslexia using speech in noise, dichotic digits and pattern of frequency tests. METHOD: forty-five children with ages ranging between 7:0 and 12:11 years were assessed; twenty children composed the dyslexic group and twenty composed the (Central) auditory processing disorder group. The tests used involved closing aural, auditory figure-ground and temporal ordering abilities. RESULTS: individuals of the (Central) auditory processing disorder group presented a higher alteration probability in the speech in noise and dichotic digits tests than those from the dyslexic group. CONCLUSION: subjects from the dyslexic group presented different patterns of (central) auditory processing disorder, with greater alteration in the tests that evaluate the temporal processing when compared to the tests that evaluate other auditory abilities.

Processamento temporal auditivo: relação com dislexia do desenvolvimento e malformação cortical / Temporal auditory processing: correlation with developmental dyslexia and cortical malformation

TEMA: processamento temporal auditivo e dislexia do desenvolvimento. OBJETIVO: caracterizar o processamento temporal auditivo em escolares com dislexia do desenvolvimento e correlacionar com malformação cortical. MÉTODO: foram avaliados 20 escolares, com idade entre 8 e 14 anos, divididos em grupo experimental (GE) composto por 11 escolares (oito do gênero masculino) com o diagnóstico de dislexia do desenvolvimento e grupo controle (GC) composto por nove escolares (seis do gênero masculino) sem alterações neuropsicolinguísticas. Após avaliações neurológica, neuropsicológica e fonoaudiológica (avaliação de linguagem e leitura e escrita) para obtenção do diagnóstico, os escolares foram submetidos à avaliação audiológica periférica e posteriormente aplicou-se o teste Random Gap Detection Test e/ou Random Gap Detection Test Expanded. RESULTADOS: observou-se diferença estatisticamente significante entre os escolares do GE e GC, com pior desempenho para o GE. A maioria dos escolares do GE apresentou polimicrogiria perisylviana. CONCLUSÃO: escolares com dislexia do desenvolvimento podem apresentar alterações no processamento temporal auditivo com prejuízo no processamento fonológico. Malformação do desenvolvimento cortical pode ser o substrato anatômico dos distúrbios.

BACKGROUND: temporal auditory processing and developmental dyslexia. AIM: to characterize the temporal auditory processing in children with developmental dyslexia and to correlate findings with cortical malformations. METHOD: twenty school-aged children, ranging in age from 8 to 14 years were evaluated. These children were divided into two groups: the experimental group (EG) was composed by 11 children (eight were male) with developmental dyslexia and the control group (CG) was composed by nine normal children (six were male). After neurological assessment and verification of the intellectual level, language, reading and writing skills in order to determine the diagnosis, children underwent a peripheral audiological evaluation and Random Gap Detection Test and/or Random Gap Detection Test Expanded. RESULTS: a statistically significant difference between children in the EG and CG were observed, with children in the EG presenting worst performances. Most of the children in the EG presented perisylvian polymicrogyria. CONCLUSION: children with developmental dyslexia may present temporal auditory processing disorders with deficits in phonological processing. Cortical malformations may be the anatomical substrate of these disorders.

Cognitive profile of children with neurofibromatosis and reading disabilities.

A large percentage of children with Neurofibromatosis Type 1(NF-1) have learning disabilities, often in the realm of reading. Previous studies have indicated that children with NF-1 show a neuropsychological profile similar to idiopathic reading disabilities (IRD); however, studies typically have not subdivided children with NF-1 into those who do and do not have RD (NF+RD and NFnoRD, respectively). The current study examined the cognitive profile of children with NF-1 with and without RD and compared them to children with IRD as well as to typically developing readers (Controls). Findings showed that children with NF+RD performed similarly to children with IRD on phonological, rapid naming, and reading comprehension measures; however, children with NF+RD displayed pronounced visual-spatial deficits as compared to IRD and Control groups. In addition, when comparing the NF-1 groups to each other as well as to the control and IRD groups, the current study reported that there were no oral language differences; lack of findings in the realm of oral language was attributed to the fact that groups were equated on IQ. Overall, findings suggest that a more refined classification of children with NF-1 may be helpful for tailoring academic interventions.

Temporal auditory processing: correlation with developmental dyslexia and cortical malformation.

BACKGROUND: Temporal auditory processing and developmental dyslexia. AIM: To characterize the temporal auditory processing in children with developmental dyslexia and to correlate findings with cortical malformations. METHOD: Twenty school-aged children, ranging in age from 8 to 14 years were evaluated. These children were divided into two groups: the experimental group (EG) was composed by 11 children (eight were male) with developmental dyslexia and the control group (CG) was composed by nine normal children (six were male). After neurological assessment and verification of the intellectual level, language, reading and writing skills in order to determine the diagnosis, children underwent a peripheral audiological evaluation and Random Gap Detection Test and/or Random Gap Detection Test Expanded. RESULTS: A statistically significant difference between children in the EG and CG were observed, with children in the EG presenting worst performances. Most of the children in the EG presented perisylvian polymicrogyria. CONCLUSION: Children with developmental dyslexia may present temporal auditory processing disorders with deficits in phonological processing. Cortical malformations may be the anatomical substrate of these disorders.

How auditory temporal processing deficits relate to dyslexia

Studies have shown that dyslexic children present a deficiency in the temporal processing of auditory stimuli applied in rapid succession. However, discussion continues concerning the way this deficiency can be influenced by temporal variables of auditory processing tests. Therefore, the purpose of the present study was to analyze by auditory temporal processing tests the effect of temporal variables such as interstimulus intervals, stimulus duration and type of task on dyslexic children compared to a control group. Of the 60 children evaluated, 33 were dyslexic (mean age = 10.5 years) and 27 were normal controls (mean age = 10.8 years). Auditory processing tests assess the abilities of discrimination and ordering of stimuli in relation to their duration and frequency. Results showed a significant difference in the average accuracy of control and dyslexic groups considering each variable (interstimulus intervals: 47.9 ± 5.5 vs 37.18 ± 6.0; stimulus duration: 61.4 ± 7.6 vs 50.9 ± 9.0; type of task: 59.9 ± 7.9 vs 46.5 ± 9.0) and the dyslexic group demonstrated significantly lower performance in all situations. Moreover, there was an interactive effect between the group and the duration of stimulus variables for the frequency-pattern tests, with the dyslexic group demonstrating significantly lower results for short durations (53.4 ± 8.2 vs 48.4 ± 11.1), as opposed to no difference in performance for the control group (62.2 ± 7.1 vs 60.6 ± 7.9). These results support the hypothesis that associates dyslexia with auditory temporal processing, identifying the stimulus-duration variable as the only one that unequally influenced the performance of the two groups.

Programa de remediação fonológica em escolares com dislexia do desenvolvimento / Phonological remediation program in students with developmental dyslexia

TEMA: programa de remediação fonológica na dislexia do desenvolvimento. OBJETIVOS: verificar a eficácia do programa de remediação fonológica em escolares com dislexia do desenvolvimento. Dentre os objetivos específicos, o estudo visou comparar o desempenho cognitivo-lingüístico de escolares com dislexia do desenvolvimento com escolares bons leitores; comparar os achados dos procedimentos de avaliação utilizados na pré e pós-testagem em escolares com dislexia submetidos e não submetidos ao programa, e comparar os achados do programa de remediação fonológica em escolares com dislexia e escolares bons leitores submetidos ao programa de remediação. MÉTODO: participaram deste estudo 24 escolares, sendo o grupo I (GI) subdivido em: GIe composto por seis escolares com dislexia do desenvolvimento submetidos ao programa, e GIc, composto por seis escolares com dislexia do desenvolvimento não submetidos ao programa. O grupo II (GII), subdividido em GIIe, composto por seis escolares bons leitores submetidos à remediação e GIIc, composto por seis escolares bons leitores não submetidos à remediação. Foi realizado programa de remediação fonológica (Gonzalez e Rosquete, 2002) em três etapas: pré-testagem, treino, pós-testagem. RESULTADOS: os resultados deste estudo revelaram que o GI apresentou desempenho inferior em habilidade fonológica, de leitura e escrita do que o GII em situação de pré-testagem. Entretanto, o GIe apresentou desempenho semelhante ao GII em situação de pós-testagem, evidenciando a eficácia do programa de remediação com habilidades fonológicas em escolares com dislexia do desenvolvimento. CONCLUSÃO: o estudo evidenciou a eficácia do treinamento com as habilidades fonológicas para os escolares com dislexia.

BACKGROUND: program for phonological remediation in developmental dyslexia. AIM: to verify the efficacy of a program for phonological remediation in students with developmental dyslexia. Specific goals of this study involved the comparison of the linguistic-cognitive performance of students with developmental dyslexia with that of students considered good readers; to compare the results obtained in pre and post-testing situations of students with dyslexia who were and were not submitted to the program; and to compare the results obtained with the phonological remediation program in students with developmental dyslexia to those obtained in good readers. METHOD: participants of this study were 24 students who were divided as follows: Group I (GI) was divided in two other groups - GIe with 6 students with developmental dyslexia who were submitted to the program; and GIc with 6 students with developmental dyslexia who were not submitted to the program; Group II (GII) was also divided in two other groups - GIIe with 6 good readers who were submitted to the program, and GIIc with 6 good readers who were not submitted to the program. The phonological remediation program (Gonzalez & Rosquete, 2002) was developed in three stages: pre-testing, training and post-testing. RESULTS: results indicate that GI presented a lower performance in phonological skills, reading and writing when compared to GII in the pre-testing situation. However, GIe presented a similar performance to that of GII in the post-testing situation, indicating the effectiveness of the phonological remediation program in students with developmental dyslexia. CONCLUSION: this study made evident the effectiveness of the phonological remediation program in students with developmental dyslexia.

Diminished auditory mismatch fields in dyslexic adults.

Electroencephalographic studies have demonstrated smaller auditory responses to infrequent deviances of speech and nonspeech sounds in dyslexic than normal-reading subjects. We used a whole-scalp neuromagnetometer to study selectively reactivity of the auditory cortices to sound deviances in 8 dyslexic and 11 normal-reading adults. Within a monotonous sequence of 50-millisecond 1000 Hz binaural tones, tones of 920 and 1080 Hz occurred with 7% probability each. Magnetic mismatch fields, elicited by the stimulus deviances, were diminished in the left hemisphere of the dyslexic subjects. The results indicate deficient change detection in the left auditory cortex of right-handed dyslexic adults.

Caracterizaçäo das alteraçöes encontradas em histórias do desenvolvimento de escolares com queixa de dificuldades do aprendizado / Characterization of the alteration in development history of a group of children whose complaints was academic

Neste trabalho, propusemo-nos a estudar a história de desenvolvimento de um grupo de crianças com queixas de dificuldade escolar e/ou no aprendizado da leitura e escrita. Realizamos uma análise do registro das informaçöes de anamnese contidas em 30 prontuários de escolares de ambos os sexos, com faixa etária entre 6 e 12 anos e 3 meses de idade, com graus de escolaridade variando de 1ª a 4ª série do Primeiro Grau de Escolas da Rede Pública de nsino. As principais alteraçöes relatadas e identificadas nas anamneses foram: alteraçöes da produçäo da fala (50,0 por cento). Alteraçöes gestacionais, do desenvolvimento de linguagem e do aspecto do desenvolvimento auditivo, intercorrências de parto, alteraçöes de voz e do desenvolvimento motor ocorreram em menores frequências

Urine patterns, peptide levels and IgA/IgG antibodies to food proteins in children with dyslexia.

There is an association between psychiatric disorders and dyslexia. In some psychiatric disorders abnormal urinary peptide patterns and peptide levels, and elevated levels of IgA antibodies to food proteins have been detected. These abnormalities are probably due to insufficient breakdown of the proteins gluten and casein. The aim of this study was to discover whether such abnormalities could be found in urine samples and serum of children with dyslexia. After screening 291 pupils in the fourth grade, 15 dyslexics and 15 controls were pairwise matched by gender, age, and cognitive level. Word decoding, spelling, and short-term memory tests were carried out, and information on handedness, immune and other disorders was obtained. Analyses of 24-h urine samples and of serum were performed. The reading abilities significantly differentiated the groups, and significant differences were found in frequency of left-handedness, immune disorders and other disorders. Three dyslexic children had elevated IgA antibodies. Two of these had positive endomycium tests, and coeliac disease was confirmed by biopsy. One had antibodies to proteins in milk. Our findings may suggest weak urinary peptide abnormalities in the dyslexic children, and they show significant differences in levels of IgA of antibodies to food proteins.

Season of birth and neurodevelopmental disorders: summer birth is associated with dyslexia.

OBJECTIVE: Increased risk for certain psychiatric disorders has been associated with season of birth. This study was undertaken to look for hypothesized season-of-birth effects for dyslexia, schizophrenia spectrum disorders, and neurological soft signs in children and adolescents. METHOD: Month of birth and the diagnostic findings in question were examined based on charts from a clinic population of 585 boys. Odds ratios and etiological fractions were calculated. RESULTS: Neurological soft signs showed a sporadic peak for June births and schizophrenia spectrum showed a peak for August and November. A smooth curve suggesting true seasonality was evident in dyslexia for births in May, June, and July. For different 5-year birth cohorts, early summer birth accounts for 24 to 71% of cases of dyslexia. CONCLUSIONS: The authors suggest that viral infection, especially influenza, during the second trimester of pregnancy is the most attractive hypothesis to explain these findings. If this hypothesis is supported, immunization in women of child-bearing age could reduce the incidence of dyslexia. Secondary prevention could also be enhanced by early identification and treatment of children who were exposed in utero.

Autoimmune thyroid disease, left-handedness, and developmental dyslexia.

Autoimmune thyroid disease (ATD) (Graves' disease and Hashimoto's thyroiditis) has been one of a number of autoimmune diseases possibly associated with left-handedness, mixed dominance, and learning disability. In the present study, 74 men with ATD were compared to 24 control men with non-ATD. An increased frequency of mixed dominance and traits suggestive of dyslexia were observed in the patients with ATD. These data are consistent with a link between the development of ATD and cerebral dominance.

The onset of Munchausen's syndrome.

Although Munchausen's syndrome is well known, its mode of onset and development are poorly understood. The authors describe an individual whose developmental history was notable for dyslexia and pathological lying from early childhood, and who later developed Munchausen's syndrome following an explosive separation from his terminally ill father. The patient's simulated genitourinary problems related directly to his father's renal malignancy. The development of his Munchausen syndrome is discussed with reference to his traumatic separation from his father as well and to his preexisting character pathology and probable central nervous system dysfunction.