A functionally guided approach to the morphometry of occipitotemporal regions in developmental dyslexia: evidence for differential effects in boys and girls.

Developmental dyslexia is a learning disability that specifically affects reading acquisition. Cortical anomalies and gray matter volume differences in various temporal regions have been reported in dyslexic subjects compared with controls. However, consistency between studies is lacking. In the present experiments, we focused our structural analyses on the ventral occipitotemporal regions, defined by their functional response to visual categories. We applied a subject-by-subject functionally guided approach on a total of 76 participants (31 dyslexic children). Cortical thickness was estimated for each participant around his/her peak of specific functional activation to visual words, faces, or places. Results from two independent datasets showed a reduction in thickness in dyslexic children compared with controls in the region responsive to words, in the left hemisphere. Additionally, a gender-by-diagnosis interaction was observed at the same location, due to differences in girls only. To avoid the potential confound of reading level, we also contrasted dyslexic and control children matched for reading performance, and we observed a similar difference, although in a smaller extent of cortex. The present study thus provides the first account of a focal cortical thickness reduction in dyslexia in the subregion of ventral occipitotemporal cortex specifically responsive to visual words, when age, gender, and reading performance are taken into account.

Planum temporale asymmetry in developmental dyslexia: Revisiting an old question.

Among the various asymmetrical structures of the human brain, the planum temporale, an anatomical region associated with a variety of auditory and language-related processes, has received particular attention. While its surface area has been shown to be greater in the left hemisphere compared to the right in about two-thirds of the general population, altered patterns of asymmetry were revealed by post mortem analyses in individuals with developmental dyslexia. These findings have been inconsistently replicated in magnetic resonance imaging studies of this disorder. In this report, we attempt to resolve past inconsistencies by analyzing the T1-weighted MR images of 81 children (mean age: 11 years, sd: 17 months), including 46 control (25 boys) and 35 dyslexic children (20 boys). We manually outlined Heschl's gyri, the planum temporale and the posterior rami of the Sylvian fissure on participants' brain images, using the same anatomical criteria as in post mortem studies. Results revealed an altered pattern of asymmetry of the planum temporale surface area in dyslexic boys only, with a greater proportion of rightward asymmetrical cases among dyslexic boys compared to control boys. Additionally, analyses of cortical thickness showed no asymmetry differences between groups for any of the regions of interest. Finally, a greater number of Heschl's gyrus full duplications emerged for the right hemisphere of dyslexic boys compared to controls. The present findings confirm and extend early post mortem observations. They also stress the importance of taking gender into account in studies of developmental dyslexia.

Predictors of developmental dyslexia in European orthographies with varying complexity.

BACKGROUND: The relationship between phoneme awareness, rapid automatized naming (RAN), verbal short-term/working memory (ST/WM) and diagnostic category is investigated in control and dyslexic children, and the extent to which this depends on orthographic complexity. METHODS: General cognitive, phonological and literacy skills were tested in 1,138 control and 1,114 dyslexic children speaking six different languages spanning a large range of orthographic complexity (Finnish, Hungarian, German, Dutch, French, English). RESULTS: Phoneme deletion and RAN were strong concurrent predictors of developmental dyslexia, while verbal ST/WM and general verbal abilities played a comparatively minor role. In logistic regression models, more participants were classified correctly when orthography was more complex. The impact of phoneme deletion and RAN-digits was stronger in complex than in less complex orthographies. CONCLUSIONS: Findings are largely consistent with the literature on predictors of dyslexia and literacy skills, while uniquely demonstrating how orthographic complexity exacerbates some symptoms of dyslexia.

Acquisition of new arithmetic skills based on prior arithmetic skills: A cross-sectional study in primary school from grade 2 to grade 5.

BACKGROUND: In several countries, children's math skills have been declining at an alarming rate in recent years and decades, and one of the explanations for this alarming situation is that children have difficulties in establishing the relations between arithmetical operations. AIM: In order to address this question, our goal was to determine the predictive power of previously taught operations on newly taught ones above general cognitive skills and basic numerical skills. SAMPLES: More than one hundred children in each school level from Grades 2 to 5 from various socio-cultural environments (N = 435, 229 girls) were tested. METHODS: Children were assessed on their abilities to solve the four basic arithmetic operations. They were also tested on their general cognitive abilities, including working memory, executive functions (i.e., inhibition and flexibility), visual attention and language. Finally, their basic numerical skills were measured through a matching task between symbolic and nonsymbolic numerosity representations. Additions and subtractions were presented to children from Grade 2, multiplications from Grade 3 and divisions from Grade 4. RESULTS AND CONCLUSIONS: We show that addition predicts subtraction and multiplication performance in all grades. Moreover, multiplication predicts division performance in both Grades 4 and 5. Finally, addition predicts division in Grade 4 but not in Grade 5 and subtraction and division are not related whatever the school grade. These results are examined considering the existing literature, and their implications in terms of instruction are discussed.

Cortical networks for vision and language in dyslexic and normal children of variable socio-economic status.

In dyslexia, anomalous activations have been described in both left temporo-parietal language cortices and in left ventral visual occipito-temporal cortex. However, the reproducibility, task-dependency, and presence of these brain anomalies in childhood rather than adulthood remain debated. We probed the large-scale organization of ventral visual and spoken language areas in dyslexic children using minimal target-detection tasks that were performed equally well by all groups. In 23 normal and 23 dyslexic 10-year-old children from two different socio-economic status (SES) backgrounds, we compared fMRI activity to visually presented houses, faces, and written strings, and to spoken sentences in the native or in a foreign language. Our results confirm a disorganization of both ventral visual and spoken language areas in dyslexic children. Visually, dyslexic children showed a normal lateral-to-medial mosaic of preferences, as well as normal responses to houses and checkerboards, but a reduced activation to words in the visual word form area (VWFA) and to faces in the right fusiform face area (FFA). Auditorily, dyslexic children exhibited reduced responses to speech in posterior temporal cortex, left insula and supplementary motor area, as well as reduced responses to maternal language in subparts of the planum temporale, left basal language area and VWFA. By correlating these two findings, we identify spoken-language predictors of VWFA activation to written words, which differ for dyslexic and normal readers. Similarities in fMRI deficits in both SES groups emphasize the existence of a core set of brain activation anomalies in dyslexia, regardless of culture, language and SES, without however resolving whether these anomalies are a cause or a consequence of impaired reading.

[Place of the BMT-i modular tool in the assessment of learning disabilities]. / Place de l'outil modulable BMT-i dans l'évaluation des troubles de l'apprentissage.

PLACE OF THE BMT-I MODULAR TOOL IN THE ASSESSMENT OF LEARNING DISABILITIES Twenty percent of children have difficulties learning to read, write, or count. Eight percent of children have a specific and durable impairment in the development of a learning or cognitive function or Learning Disabilities (LD), often called «dys¼ (dysphasia, dyslexia, dysorthography, dyscalculia, dysgraphia, etc.). This is a public health problem, which has been addressed by the Haute Autorité de Santé (HAS), which recommends a health program based on the needs of each child, coordinating education and health professionals - rehabilitation specialists and medical prescribers. The role of the child's doctor is essential in the first line of action to identify these problems, to examine the child, to prescribe reeducation when necessary and to follow the evolution. However, he has received little training. The modular BMT-i (computerized adaptable test battery) tool is validated, easy to use and reliable. It allows the screening of difficulties in each domain in 10 to 25 minutes in front of a complaint by selecting the appropriate tests. A choice of clinical situations helps to understand the disorders and the approach of the examination of the child, to inform the families of the results, to accompany them on the therapeutic project and to prescribe the care adapted to each situation.

PLACE DE L'OUTIL MODULABLE BMT-I DANS L'ÉVALUATION DES TROUBLES DE L'APPRENTISSAGE Vingt pour cent des enfants sont en difficulté pour apprendre à lire, écrire et/ou compter. Huit pour cent des enfants présentent une altération durable et spécifique du développement d'un apprentissage ou d'une fonction cognitive (« troubles spécifiques du langage et des apprentissages ¼ [TSLA]), souvent simplifié sous le terme « dys ¼ (dysphasie, dyslexie, dysorthographie, dyscalculie, dysgraphie, etc.). La Haute Autorité de santé s'est saisie de ce problème de santé publique et recommande un parcours de santé ciblé sur les besoins de chaque enfant, coordonnant professionnels de l'éducation et de la santé ­ rééducateurs et médecins prescripteurs. Le rôle du médecin est essentiel en premier recours pour identifier les enfants concernés, les examiner, prescrire les rééducations nécessaires et suivre l'évolution. L'outil modulable BMT-i (batterie modulable de tests informatisée) validé, simple d'utilisation et fiable, permet le dépistage des difficultés dans chaque domaine en dix à vingt-cinq minutes, en sélectionnant les épreuves adéquates. Un choix de situations cliniques aide à la compréhension des troubles et à la démarche de l'examen de l'enfant, afin d'informer les familles des résultats, les accompagner dans les actions à mener et prescrire les soins adaptés à chaque situation.

The Computerized Adaptable Test Battery (BMT-i) for Rapid Assessment of Children's Academic Skills and Cognitive Functions: A Validation Study.

Background: Learning disabilities in children are a major public health concern worldwide, having a prevalence of 8%. They are associated with lost social, educational, and ultimately, professional opportunities for individuals. These disabilities are also very costly to governments and raise the issue of the appropriate means of screening. Unfortunately, validated tools for preliminary appraisal of learning and cognitive function in struggling children are presently restricted to specific age ranges and cognitive domains. This study sought to validate a first-line battery for assessment of academic skills and cognitive functions. Materials and Methods: The computerized Adaptable Test Battery, or BMT-i, includes a panel of tests for the first-line assessment of children's academic skills and cognitive functions. The tests reflect expected abilities for the age group in question, exploring academic skills (written language and mathematical cognition) and cognitive domains (verbal, non-verbal, and attentional/executive functions). The authors relied on the results of these tests for a sample of 1,074 Francophone children representative of the mainland French school-age population (522 boys and 552 girls, ages 4-13, from 39 classes at 7 public and 5 private schools). Thirteen speech-language pathologists and neuropsychologists individually administered the tests. Results: The psychometric characteristics of the empirical data obtained showed acceptable to good test homogeneity, internal consistency (Cronbach's alpha: > 0.70), test-retest reliability (intraclass correlation coefficients: ~0.80), and consistency with reference test batteries (r: 0.44-0.96). Conclusion: The BMT-i was validated in a large sample of children in mainstream French schools, paving the way for its use in first-line screening of learning disabilities among children with complaints, whether their learning difficulties have been flagged by their parents or by their teachers.

External Validation of BMT-i Computerized Test Battery for Diagnosis of Learning Disabilities.

Background: Learning disabilities (LDs) are a major public health issue, affecting cognitive functions and academic performance for 8% of children. If LDs are not detected early and addressed through appropriate interventions, they have a heavy impact on these children in the social, educational, and professional spheres, at great cost to society. The BMT-i (Batterie Modulable de Tests informatisée, or "computerized Adaptable Test Battery") enables fast, easy, reliable assessments for each cognitive domain. It has previously been validated in children ages 4-13 who had no prior complaints. The present study demonstrates the sensitivity of the BMT-i, relative to reference test batteries, for 191 children with cognitive difficulties. Materials and Methods: These 191 subjects were included in the study by the 14 pediatricians treating them for complaints in five cognitive domains: written language [60 (cases)]; mathematical cognition (40); oral language (60); handwriting, drawing, and visuospatial construction (45); and attention and executive functioning (45). In accordance with a predefined protocol, the children were administered BMT-i tests first, by their pediatricians, and reference tests later, by specialists to whom the BMT-i test results were not disclosed. Comparison of BMT-i and reference test results made it possible to evaluate sensitivity and agreement between tests. Results: For each of the five domains, the BMT-i was very sensitive (0.91-1), and normal BMT-i results were highly predictive of normal results for specialized reference tests [negative likelihood ratio (LR-): 0-0.16]. There was close agreement between BMT-i and reference tests in all domains except attention and executive functioning, for which only moderate agreement was observed. Conclusion: The BMT-i offers rapid, reliable, simple computerized assessments whose sensitivity and agreement with reference test batteries make it a suitable first-line instrument for LD screening in children 4-13 years old.

Specific language impairment versus Landau-Kleffner syndrome.

The occurrence of sleep electroencephalography (EEG) abnormalities in some children with specific language impairment (SLI), the various forms of language dysfunction patterns seen in children with benign childhood epilepsy with centrotemporal spikes (BECTS), and finally the acquired aphasia in Landau-Kleffner syndrome (LKS) indicate a large spectrum of interactions between language and epilepsy. As such, the question is whether SLI and LKS should rather be considered along a continuum or as two entirely distinct entities. In addition, the rationale for using antiepileptic medications in rare forms of SLI is discussed.

Serial order short-term memory capacities and specific language impairment: no evidence for a causal association.

This study re-explored the nature of verbal short-term memory (STM) deficits in children with specific language impairment (SLI), by distinguishing item and serial order STM processes. Recent studies have shown serial order STM capacity to be a critical determinant of language development, relative to item STM. In Experiment 1, 12 children with SLI, 12 age-matched children and 12 language-matched children were administered serial order recognition and reconstruction tasks. Experiment 2 assessed implicit serial learning abilities via a Hebb learning task. The SLI group showed impaired performance for the serial order reconstruction and recognition tasks, relative to language-matched and/or age-matched control groups. However, normal serial position effects were observed in all SLI children in the serial order reconstruction task, suggesting normal coding of serial position information. Similarly, performance on the Hebb serial learning task was at chronological age appropriate levels. Experiment 3 showed that the group differences observed for the serial order STM tasks in Experiment 1 disappeared when the SLI group was compared to a mental age-matched control group. Experiment 4 showed similar performance levels in the SLI group and the mental age-matched control group for a nonword recognition task assessing item STM capacities. This study shows that children with SLI have no specific impairments for serial order and item STM components but that poorer general cognitive efficiency is related to functional limitations in verbal STM tasks. The data are in line with limited information processing accounts of SLI.

Atypical language impairment in two siblings: relationship with electrical status epilepticus during slow wave sleep.

We report the case of a young girl who presented severe learning disabilities in oral and written language related to a continuous spike-waves during slow sleep (CSWS) syndrome. A sleep EEG recording obtained in her younger brother, who presented a clinical pattern suggesting developmental dysphasia, also showed a CSWS syndrome. These two clinical cases underscore the need to look for this syndrome in the siblings of an affected child when learning difficulties appear in a child who previously had normal psychomotor development.

Cognitive functions in children with benign childhood epilepsy with centrotemporal spikes (BECTS).

Benign childhood epilepsy with centrotemporal spikes (BECTS) is regarded as a benign form of epilepsy because of its usually favorable outcome, in terms of seizures. Eighteen children with BECTS were studied in terms of neuropsychological and learning abilities: intellectual quotient, oral language (phonological production, naming skills, verbal fluency and syntactic comprehension), drawing and visuo-spatial skills, visual and selective attention, verbal and visuo-spatial memory, reading, numeracy and spelling. The mean IQ of the population was within the normal range, but individual results were heterogeneous. Verbal functions and memory were normal. In contrast, drawing and visuo-spatial skills, attention and visuo-spatial memory were significantly weak compared to the normal range for age. Reading, numeracy and/or spelling ability were significantly delayed by one academic year or more in ten of the children. In conclusion, despite its benign outcome in terms of epilepsy, BECTS can be accompanied by specific cognitive disorders and low academic achievement.

Phonological skills, visual attention span, and visual stress in developmental dyslexia.

In this study, we concurrently investigated 3 possible causes of dyslexia-a phonological deficit, visual stress, and a reduced visual attention span-in a large population of 164 dyslexic and 118 control French children, aged between 8 and 13 years old. We found that most dyslexic children showed a phonological deficit, either in terms of response accuracy (92.1% of the sample), speed (84.8%), or both (79.3%). Deficits in visual attention span, as measured by partial report ability, affected 28.1% of dyslexic participants, all of which also showed a phonological deficit. Visual stress, as measured by subjective reports of visual discomfort, affected 5.5% of dyslexic participants, not more than controls (8.5%). Although phonological variables explained a large amount of variance in literacy skills, visual variables did not explain any additional variance. Finally, children with comorbid phonological and visual deficits did not show more severe reading disability than children with a pure phonological deficit. These results (a) confirm the importance of phonological deficits in dyslexia; (b) suggest that visual attention span may play a role, but a minor one, at least in this population; (c) do not support any involvement of visual stress in dyslexia. Among the factors that may explain some differences with previously published studies, the present sample is characterized by very stringent inclusion criteria, in terms of the severity of reading disability and in terms of exclusion of comorbidities. This may exacerbate the role of phonological deficits to the detriment of other factors playing a role in reading acquisition. (PsycINFO Database Record

Genetic analysis of dyslexia candidate genes in the European cross-linguistic NeuroDys cohort.

Dyslexia is one of the most common childhood disorders with a prevalence of around 5-10% in school-age children. Although an important genetic component is known to have a role in the aetiology of dyslexia, we are far from understanding the molecular mechanisms leading to the disorder. Several candidate genes have been implicated in dyslexia, including DYX1C1, DCDC2, KIAA0319, and the MRPL19/C2ORF3 locus, each with reports of both positive and no replications. We generated a European cross-linguistic sample of school-age children - the NeuroDys cohort - that includes more than 900 individuals with dyslexia, sampled with homogenous inclusion criteria across eight European countries, and a comparable number of controls. Here, we describe association analysis of the dyslexia candidate genes/locus in the NeuroDys cohort. We performed both case-control and quantitative association analyses of single markers and haplotypes previously reported to be dyslexia-associated. Although we observed association signals in samples from single countries, we did not find any marker or haplotype that was significantly associated with either case-control status or quantitative measurements of word-reading or spelling in the meta-analysis of all eight countries combined. Like in other neurocognitive disorders, our findings underline the need for larger sample sizes to validate possibly weak genetic effects.

The influence of socioeconomic status on children's brain structure.

Children's cognitive abilities and school achievements are deeply affected by parental socioeconomic status (SES). Numerous studies have reported lower cognitive performance in relation to unfavorable environments, but little is known about the effects of SES on the child's neural structures. Here, we systematically explore the association between SES and brain anatomy through MRI in a group of 23 healthy 10-year-old children with a wide range of parental SES. We confirm behaviorally that language is one of the cognitive domains most affected by SES. Furthermore, we observe widespread modifications in children's brain structure. A lower SES is associated with smaller volumes of gray matter in bilateral hippocampi, middle temporal gyri, left fusiform and right inferior occipito-temporal gyri, according to both volume- and surface-based morphometry. Moreover, we identify local gyrification effects in anterior frontal regions, supportive of a potential developmental lag in lower SES children. In contrast, we found no significant association between SES and white matter architecture. These findings point to the potential neural mediators of the link between unfavourable environmental conditions and cognitive skills.

School performance in a cohort of children with CNS inflammatory demyelination.

BACKGROUND: Acute CNS inflammatory demyelination in childhood may induce permanent cognitive impairment. However, there has been no epidemiological assessment of prognostic factors for school performance in a cohort of children with such a disease. METHODS: The cohort consisted of 344 children from the French "KIDSEP" neuropediatric cohort with at least one clinically defined attack of CNS inflammatory demyelination occurring before the age of 16 years, and with at least two years of follow-up (inclusion from 1990 to 2003, follow-up until June 2007). We used multivariate survival analysis (Cox model) to evaluate the prognostic value for grade retention between the start of elementary school ( approximately 6 years of age) and the end of high school ( approximately 17-18 years of age), of variables related to both the socioeconomic status of the parents and the characteristics of the disease at onset. RESULTS: The cohort was monitored for a mean of 8.0+/-3.4 years. Grade retention after disease onset was recorded for 151 patients (43.9%). The risk of grade retention was significantly higher for boys, children from families with lower social status and poorer housing conditions, children over the age of 11 years at disease onset and children suffering optic neuritis or brainstem dysfunction at the first attack or irreversible disability, even if only moderate, following the first attack. CONCLUSIONS: The risk factors for poor school performance are related to low socioeconomic status and to factors predictive of a relapsing severe course of the disease, leading to the diagnosis of multiple sclerosis.

Auditory and visual stream segregation in children and adults: an assessment of the amodality assumption of the 'sluggish attentional shifting' theory of dyslexia.

Among the hypotheses relating dyslexia to a temporal processing disorder, Hari and Renvall (Hari, R., Renvall, H., 2001. Impaired processing of rapid stimulus sequences in dyslexia. Trends. Cognit. Sci. 5, 525-532.) argued that dyslexic individuals would show difficulties at an attentional level, through sluggish attentional shifting (SAS) in all sensory modalities. However, the amodality assumption of the SAS theory was never straightforwardly assessed in the same group of dyslexic participants using similar paradigms in both the visual and auditory modalities. Here, the attentional sequential performance of control and dyslexic participants was evaluated using rapid serial presentation paradigms measuring individual stream segregation thresholds in the two modalities. The first experiment conducted on French dyslexic children with a phonological disorder revealed an SAS only in the auditory modality only which was strongly related to reading performance. The second experiment carried out on British dyslexic young adults with a phonological disorder using the same auditory segregation task but a different visual paradigm revealed an SAS in both the visual and the auditory modalities. In addition, a relationship was found in this group between SAS, poor reading and poor phonological skills. Two further control experiments showed that differences in task design or participants' language between Experiments 1 and 2 could not account for the differences in terms of visual segregation patterns. Overall, our results support the view that the auditory SAS plays a role in developmental dyslexia via its impact on phonological abilities. In addition, a visual temporal disorder in dyslexia might emerge at a later developmental stage, when the visual system normally becomes more expert at rapid temporal processing.

Poor reading in French elementary school: the interplay of cognitive, behavioral, and socioeconomic factors.

BACKGROUND: : Reading impairment is the major learning disability in childhood. Most previous studies were done on English-speaking populations. Yet, it has been argued that the English writing system exacerbates phonological deficits because of its exceptionally high inconsistency between spelling and sound. Thus, cross-language studies are needed to explore the universal versus language-specific factors underlying reading impairment. The goal of the present research was to study biological, socioeconomic, cognitive, and behavioral factors underlying poor reading in French-speaking second grade children. METHODS: : A total of 1062 children from 20 different schools in the city of Paris participated in the study. After an initial test phase, children with a suspected impairment in reading acquisition were assessed individually. Subsequently, 100 poor readers and 50 controls were matched for sex, age, school, and neighborhood socioeconomic status (SES). They underwent comprehensive medical, cognitive, and behavioral assessment complemented by individual socioeconomic data. RESULTS: : The average prevalence of reading impairment was around 12% in our sample. It was highly influenced by neighborhood SES, varying from 3.3% in high SES to 24.2% in low SES areas. Among the individual SES variables, low maternal education significantly distinguished poor from typical readers. Multiple regression analyses showed that reading outcome was best predicted by phonological awareness skills and attention deficits. CONCLUSION: : The majority of poor readers come from low SES areas. As in the English literature, the most robust predictor for reading impairment is phonological awareness. In addition, behavioral problems, such as attention deficits, seem to aggravate reading deficits for children with weak phonological awareness skills.

Long-term evaluation of the impact of the h1-receptor antagonist cetirizine on the behavioral, cognitive, and psychomotor development of very young children with atopic dermatitis.

The impact of the prolonged use of cetirizine at high dose (0.25 mg/kg twice a day over 18 mo) on behavior and cognitive ability was examined in a double-blind, randomized, placebo-controlled trial (ETAC-Early Treatment of the Atopic Child) designed to establish whether it was possible to prevent young children (1-2 y old at study entry) with atopic dermatitis from developing asthma. Well-validated and standardized measures of behavior (Behavior Screening Questionnaire) and cognition (McCarthy Scales of Children's Abilities) were used. In addition, the ages of attainment of psychomotor milestones were established. These measures were taken between an average of 32 and 53 mo of age, both during the study treatment with cetirizine or placebo and after the study treatment had been discontinued. The Behavior Screening Questionnaire was completed at least once on approximately 300 children in each group and on approximately 200 children on five occasions. The McCarthy Scales of Children's Abilities were administered to approximately 100 in each group at three different times. There were no significant differences between the cetirizine and placebo groups on either of the behavior and cognition measures or in psychomotor milestones during or after the study treatment. These findings suggest that there are no adverse effects on behavior or learning processes associated with the prolonged use of cetirizine in young children with atopic dermatitis.