A Systematic Review on Visual-Processing Deficits in Neurofibromatosis Type 1: What Possible Impact on Learning to Read?

This systematic review aimed to examine the possible implication of visual-perceptual, visuo-attentional and oculomotor processing in the reading deficits frequently experienced by children with Neurofibromatosis type 1 (NF1), as previously shown in dyslexia. Using PRISMA methodological guidelines, we examined 49 studies; most of these reported visual-processing deficits in this population, raising the importance of directly studying the visuo-perceptual and visuo-attentional processes and eye-movement control involved in the learning-to-read process in NF1. The discussion provides a reflection for a better understanding of how visual-processing skills interact with reading deficits in NF1, as well as new avenues for their screening and care.

Bioenvironmental Predictors of Childhood Reading and Speech Difficulties.

PURPOSE: Reading and speech difficulties are common in childhood, yet it is not fully understood how much of their etiology is shared. This partly derives from methodological issues related to overlooking the potential co-occurrence between the two sets of difficulties. This study investigated the effects of five bioenvironmental predictors in a sample assessed for such co-occurrence. METHOD: A combination of exploratory and confirmatory analyses was performed on longitudinal data from the National Child Development Study. Exploratory latent class analysis was performed on children's reading, speech, and language outcomes at ages 7 and 11 years. Membership in the obtained classes was modeled using a regression with sex and four early-life predictors: gestation period, socioeconomic status, maternal education, and the home reading environment. RESULTS: The model yielded four latent classes that broadly reflected (1) average reading and speech, (2) excellent reading, (3) reading difficulties, and (4) speech difficulties. Early-life factors significantly predicted class membership. Male sex and preterm birth emerged as risk factors for both reading and speech difficulties. Protective effects against reading difficulties were identified for maternal education, and lower (but not higher) levels of socioeconomic status and the home reading environment. CONCLUSIONS: Co-occurrence of reading and speech difficulties in the sample was low, and differential patterns of effect of the social environment were supported. Reading outcomes were under stronger malleable influence than speech outcomes.

Visual-processing deficits in children with neurofibromatosis type 1: A clinical marker of reading difficulties.

Today's estimates indicate that nearly 50% of children with Neurofibromatosis type 1 (NF1) suffer from reading disabilities, with a high impact on their academic achievement. In addition to the well-documented importance of phonological skills in reading acquisition and neurodevelopmental disorders, visual-attention processes also appear as important factors in learning to read. The present study aimed at assessing the role of visual-processing dysfunction in the high prevalence of reading disabilities in NF1 children and providing a useful tool for clinician in the early detection of reading impairment in this neurogenetic disorder. Forty-two children with NF1 and 42 typically developing children (TD) participated in the study. All were right-handed and did not present intellectual disability or attention deficit hyperactivity disorder. Visual-attention processes were assessed with the Developmental Eye Movement (DEM) test, together with the NF1 children's reading level. NF1 children with and without reading disabilities were then compared. The results showed that visual-processing deficits were highly present among the NF1 children included in our study. Furthermore, poor readers with NF1 presented an increased risk of visual-processing deficits compared to peers. This finding supports the role of visual-processing deficits in the reading difficulties encountered in nearly half of children with NF1. Finally, in NF1 children without intellectual or attention disability, visual-processing deficits emerge as one of the clinical markers of reading disabilities. The study holds important clinical implications both for the identification, by providing a useful screening tool, and the management of reading disabilities in NF1 children.

The resilience of the developing reading system: multi-modal evidence of incident and recovery after a pediatric stroke.

Decades of neuroscientific findings have elucidated the highly specialized brain areas involved in reading, especially along the ventral occipitotemporal stream where the critical step of recognizing words occurs. We report on a 14-year-old female with temporary dyslexia after a left ventral occipitotemporal ischemic stroke. Our longitudinal multimodal findings show that the resolution of the reading impairment was associated with heightened activity in the left posterior superior and inferior temporal gyri. Our findings highlight the role of the left inferior temporal gyrus in reading and the importance of perilesional and ipsilateral cortical areas for functional recovery after childhood stroke.

Development of thalamus mediates paternal age effect on offspring reading: A preliminary investigation.

The importance of (inherited) genetic impact in reading development is well established. De novo mutation is another important contributor that is recently gathering interest as a major liability of neurodevelopmental disorders, but has been neglected in reading research to date. Paternal age at childbirth (PatAGE) is known as the most prominent risk factor for de novo mutation, which has been repeatedly shown by molecular genetic studies. As one of the first efforts, we performed a preliminary investigation of the relationship between PatAGE, offspring's reading, and brain structure in a longitudinal neuroimaging study following 51 children from kindergarten through third grade. The results showed that greater PatAGE was significantly associated with worse reading, explaining an additional 9.5% of the variance after controlling for a number of confounds-including familial factors and cognitive-linguistic reading precursors. Moreover, this effect was mediated by volumetric maturation of the left posterior thalamus from ages 5 to 8. Complementary analyses indicated the PatAGE-related thalamic region was most likely located in the pulvinar nuclei and related to the dorsal attention network by using brain atlases, public datasets, and offspring's diffusion imaging data. Altogether, these findings provide novel insights into neurocognitive mechanisms underlying the PatAGE effect on reading acquisition during its earliest phase and suggest promising areas of future research.

Relação entre avaliações de leitura em escolares e queixas relatadas pelos responsáveis / Relationship between reading assessments in schoolchildren and complaints reported by guardians / Relación entre evaluaciones de lectura en escolares y denuncias reportadas por tutores

Introdução: Ler significa processar informações e transformar material escrito em fala e em significado. As pessoas que tiverem aprendido a ler terão desenvolvido um sistema mental de processamento de informações capaz de realizar essas transformações. Objetivo: correlacionar as habilidades de leitura e as queixas relacionadas à leitura de estudantes do terceiro ano do ensino fundamental. Método: 40 escolares de ambos os gêneros, idade média de 8,16 anos. Avaliou-se decodificação, fluência e compreensão textual, e as queixas relacionadas à leitura foram levantadas. Resultados: houve 37,5% de incidência de pelo menos uma queixa relacionada à leitura, prevalecendo a leitura lenta; acertos nos estímulos regulares foram estatisticamente superiores aos demais estímulos; os acertos na fluência variaram entre 0 e 45, o desempenho na compreensão leitora foi alto, sem diferença estatística entre questões inferenciais e literais; houve correlação entre as habilidades de leitura entre si, e entre a queixa "não lê" com estas habilidades. Conclusão: confirmou-se que a melhor decodificação favorece a fluência, que otimiza a compreensão leitora; a queixa "não lê" correlacionou-se com todas as avaliações de leitura, indicando os pais sensíveis à leitura de seus filhos.

Introduction: Reading means processing information and transforming written material into speech and meaning. People who have learned to read will have developed a mental information processing system capable of carrying out these transformations. Objective: To correlate reading skills and reading-related complaints of third grade students. Method: 40 students of both genders, mean age 8.16 years. Decoding, fluency and textual comprehension were evaluated, and reading-related complaints were raised. Results: there was a 37.5% incidence of at least one reading-related complaint, with slow reading prevailing; hits on regular stimuli were statistically superior to other stimuli; fluency scores ranged from 0 to 45, reading comprehension performance was high, with no statistical difference between inferential and literal questions; There was a correlation between reading skills among themselves, and between the complaint "not reading" with these skills. Conclusion: the incidence of reading-related complaints was high, and slow reading prevailed. It was confirmed that the best decoding favors fluency, which optimizes reading comprehension; the "not reading" complaint correlated with all reading assessments, indicating parents sensitive to their children's reading.

Introducción: Leer significa procesar información y transformar el material escrito en habla y significado. Las personas que han aprendido a leer habrán desarrollado un sistema de procesamiento de información mental capaz de realizar estos cambios. Objetivo: correlacionar las habilidades de lectura y las quejas relacionadas con la lectura de los estudiantes en el tercer año de la escuela primaria. Método: 40 estudiantes de ambos sexos, edad media 8,16 años. Se evaluaron la decodificación, fluidez y comprensión textual, y se plantearon quejas relacionadas con la lectura. Resultados: hubo una incidencia del 37,5% de al menos una queja relacionada con la lectura, prevaleciendo la lectura lenta; los golpes en estímulos regulares fueron estadísticamente superiores a otros estímulos; la fluidez correcta varió entre 0 y 45, el rendimiento de comprensión de lectura fue alto, sin diferencias estadísticas entre preguntas inferenciales y literales; existía una correlación entre las habilidades de lectura entre ellos y entre la queja "no leer" con estas habilidades. Conclusión: se confirmó que la mejor decodificación favorece la fluidez, lo que optimiza la comprensión de lectura; la queja "no lee" se correlacionó con todas las evaluaciones de lectura, lo que indica que los padres son sensibles a la lectura de sus hijos.

A sibling-comparison study of smoking during pregnancy and risk for reading-related problems.

This research examines the relationship between smoking during pregnancy (SDP) and risk for reading related problems in siblings discordant for exposure to SDP. Data (N = 173 families) were drawn from the Missouri Mothers and Their Children study, a sample, identified using birth records (years 1998-2005), in which mothers changed her smoking behavior between two pregnancies (Child 1 [older sibling]: M = 12.99; Child 2 [younger sibling]: M = 10.19). A sibling comparison approach was used, providing a robust test for the association between SDP and reading related outcomes in school-aged children. Results suggested within-family (i.e., potentially causal) associations between SDP and reading and language/comprehension factor scores, as well as between SDP and specific reading-related skills, including reading accuracy and receptive language, with increased exposure to SDP associated with decreased performance. SDP was not associated with spelling, reading rate, or receptive vocabulary. Initial within-family associations between SDP and word-letter identification, phonetic/decoding skills, and reading comprehension were fully attenuated following partial control for genetic and environmental confounding of the associations. These findings indicate that exposure to SDP is associated with poorer performance on some, but not all skills assessed.

Is part-time special education beneficial for children at risk for reading difficulties? An example from Estonia.

This longitudinal quasi-experimental study examined the general efficiency of part-time special education for students at risk for reading difficulties in Estonian primary schools. Participants were selected from 464 students whose pre-reading and reading skills were assessed for the study at the beginning of school. Eighty-four of these children received part-time special education support throughout the first grade (treatment group). Statistical matching was used to find a control group similar to the treatment group on pre-reading skills and parental educational level but who did not receive extra help (control group; 84 children). Students' reading fluency and task persistence were assessed at the end of Grade 1 and Grade 2. Neither group differed in reading fluency nor task persistence at the end of either grade. Developmental trajectories of those treatment group children who received additional support only for reading and spelling difficulties did not differ from those who received this support for concurrent developmental disorders in addition to reading and spelling difficulties. Our findings indicate that a full-year of special education support in the form of extra lessons without a prior diagnostic assessment, frequent progress monitoring, or focused interventions might not be an effective way to support children with reading difficulties.

School-entry language outcomes in late talkers with and without a family risk of dyslexia.

Children with familial risk (FR) of dyslexia and children with early language delay are known to be at risk for later language and literacy difficulties. However, research addressing long-term outcomes in children with both risk factors is scarce. This study tracked FR and No-FR children identified as late talkers at 2 years of age and reports development from 4;6 through 6 years. We examined the possible effects of FR-status and late talking (LT) status, respectively, on language skills at school entry, and whether FR-status moderated the associations between 4;6-year and 6-year language scores. Results indicated an effect of LT status on language at both ages, while FR status affected language skills at 6 years only. The interaction between LT and FR statuses was not significant, implying that LT status affected language skills independently of the child's FR status. A proportion of late talkers developed typical language at 6 years of age, while some FR children with typical vocabulary skills in toddlerhood had emerging developmental language disorder by school entry. FR status had a moderating effect on the association between expressive grammar at ages 4;6 and 6 years. Possible explanations for the effect of FR status on language skills are discussed. We highlight limitations in the study size and suggest how these preliminary findings can inform future research.

Profiling the Word Reading Abilities of School-Age Children with Neurofibromatosis Type 1.

OBJECTIVE: Reading difficulties are one of the most significant challenges for children with neurofibromatosis type 1 (NF1). The aims of this study were to identify and categorize the types of reading impairments experienced by children with NF1 and to establish predictors of poor reading in this population. METHOD: Children aged 7-12 years with NF1 (n = 60) were compared with typically developing children (n = 36). Poor word readers with NF1 were classified according to impairment type (i.e., phonological, surface, mixed), and their reading subskills were compared. A hierarchical multiple regression was conducted to identify predictors of word reading. RESULTS: Compared to controls, children with NF1 demonstrated significantly poorer literacy abilities. Of the 49 children with NF1 classified as poor readers, 20 (41%) were classified with phonological dyslexia, 24 (49%) with mixed dyslexia, and 5 (10%) fell outside classification categories. Children with mixed dyslexia displayed the most severe reading impairments. Stronger working memory, better receptive language, and fewer inattentive behaviors predicted better word reading skills. CONCLUSIONS: The majority of children with NF1 experience deficits in key reading skills which are essential for them to become successful readers. Weaknesses in working memory, receptive language, and attention are associated with reading difficulties in children with NF1.

Language difficulties are a shared risk factor for both reading disorder and mathematics disorder.

Disorders of reading and mathematics co-occur at greater than chance rates, but they are often studied separately. This article reports the reading and arithmetic outcomes at 9 years of age from a longitudinal study of 224 children at high risk for dyslexia. Using a cutoff at the 10th centile, groups of children with reading disorder (RD), mathematics disorder (MD), and comorbid reading disorder and math disorder (RD&MD) were identified. The risk of these disorders was elevated in children selected in preschool with language difficulties or at family risk for dyslexia. There was a high degree of comorbidity between RD and MD, and many cases-particularly in the comorbid group-also reached the diagnostic threshold for developmental language disorder (DLD). On measures of language, phoneme awareness, rapid automatized naming (RAN) digits, and rated inattention, there was a stepwise pattern: RD > MD > RD&MD. Poor language was associated with each disorder and appears to be a cognitive risk factor for RD, MD, and RD&MD. These findings suggest that there are shared genetic risk factors operating for both RD and MD.

A genetic window to auditory-verbal problems in bipolar disorder.

Bipolar disorder is a high prevalent psychiatric condition entailing recurrent episodes of elevated mood and depression, but also diverse cognitive problems. One deficit observed in patients concerns to auditory-verbal processing. Being a hereditary condition with a complex genetic architecture, it is not clear which genes contribute to this deficit. We show that candidates for bipolar disorder significantly overlap with candidates for clinical conditions resulting from a deficit in the phonological loop of working memory, particularly, developmental dyslexia and specific language impairment. The overlapping genes are involved in aspects of brain development and function (particularly, brain oscillations) potentially underlying phonological processing and accordingly, emerge as promising candidates for auditory-verbal deficits in bipolar disorder.

A universal reading network and its modulation by writing system and reading ability in French and Chinese children.

Are the brain mechanisms of reading acquisition similar across writing systems? And do similar brain anomalies underlie reading difficulties in alphabetic and ideographic reading systems? In a cross-cultural paradigm, we measured the fMRI responses to words, faces, and houses in 96 Chinese and French 10-year-old children, half of whom were struggling with reading. We observed a reading circuit which was strikingly similar across languages and consisting of the left fusiform gyrus, superior temporal gyrus/sulcus, precentral and middle frontal gyri. Activations in some of these areas were modulated either by language or by reading ability, but without interaction between those factors. In various regions previously associated with dyslexia, reading difficulty affected activation similarly in Chinese and French readers, including the middle frontal gyrus, a region previously described as specifically altered in Chinese. Our analyses reveal a large degree of cross-cultural invariance in the neural correlates of reading acquisition and reading impairment.

Asymmetric Bálint's syndrome with multimodal agnosia, bilateral agraphesthesia, and ineffective kinesthetic reading due to subcortical hemorrhage in the left parieto-occipito-temporal area.

We report a patient with asymmetric Bálint's syndrome (predominantly right-sided oculomotor apraxia and simultanagnosia and optic ataxia for the right hemispace), and multimodal agnosia (apperceptive visual agnosia and bilateral associative tactile agnosia) with accompanying right hemianopia, bilateral agraphesthesia, hemispatial neglect, global alexia with unavailable kinesthetic reading, and lexical agraphia for kanji (Japanese morphograms), after hemorrhage in the left parieto-occipito-temporal area. The coexistence of tactile agnosia, bilateral agraphesthesia, and ineffective kinesthetic reading suggests that tactile-kinesthetic information can be interrupted because of damage to the fiber connection from the parietal lobe to the occipito-temporal area, leading to these tactually related cognitive impairments.

A Rare Clinical Antity; Pure Gerstmann Syndrome.

Gerstmann syndrome is defined as a tetrad including agraphia, acalculia, finger agnosia, and right-left disorientation. In the case studies presented in the literature, it has been reported that Gerstmann syndrome usually appears as an incomplete tetrad of symptoms or accompanied by cognitive deficits including aphasia, alexia, apraxia and some perceptual disorders. Here, we present of the patient with left angular and supramarginal gyrus infarction affecting the parietal lobe. In addition to the symptoms mentioned above, the patient had alexia and anomic aphasia as well. We discussed the clinic appearance and reviewed the current literature.

Does an impaired lexicon produce legitimate alternative reading of components (LARC) errors in reading Japanese Kanji? Evidence from two-Kanji compound word reading in a Japanese-speaking patient with aphasia.

Several studies have reported a strong association between semantic system impairment and LARC error production. However, our patient with a left temporal lobe contusion, including the fusiform gyrus, showed LARC errors even in two-Kanji compound words, the meanings of which the patient understood. Also, the poor results of lexical decision and picture naming suggested problems in orthographic and phonological retrieval. From these results, we concluded that at least some LARC errors are independent of semantic impairment, and other explanations are needed for this type of error.

The Prevalence of Dyslexia: A New Approach to Its Estimation.

How prevalent is dyslexia? A definitive answer to this question has been elusive because of the continuous distribution of reading performance and predictors of dyslexia and because of the heterogeneous nature of samples of poor readers. Samples of poor readers are a mixture of individuals whose reading is consistent with or expected based on their performance in other academic areas and in language, and individuals with dyslexia whose reading is not consistent with or expected based on their other performances. In the present article, we replicate and extend a new approach for determining the prevalence of dyslexia. Using model-based meta-analysis and simulation, three main results were found. First, the prevalence of dyslexia is better represented as a distribution that varies as a function of severity as opposed to any single-point estimate. Second, samples of poor readers will contain more expected poor readers than unexpected or dyslexic readers. Third, individuals with dyslexia can be found across the reading spectrum as opposed to only at the lower tail of reading performance. These results have implications for screening and identification, and for recruiting participants for scientific studies of dyslexia.

Dissociations within neglect-related reading impairments: Egocentric and allocentric neglect dyslexia.

Consistently lateralized reading errors are commonly understood as side-effects of visuospatial neglect impairment. There is however a qualitative difference between systematically omitting full words presented on one side of passages (egocentric neglect dyslexia) and lateralized errors when reading single words (allocentric neglect dyslexia). This study aims to investigate the relationship between egocentric and allocentric neglect dyslexia and visuospatial neglect.1209 stroke survivors completed standardized reading and cancellation tests. Stringent criteria identified unambiguous cases of allocentric neglect dyslexia (N = 17) and egocentric neglect dyslexia (N = 35). These conditions were found to be doubly dissociated with all cases of egocentric and allocentric neglect dyslexia occurring independently. Allocentric neglect dyslexia was dissociated from both egocentric and allocentric visuospatial neglect. Additionally, two cases of allocentric neglect dyslexia which co-occurred with oppositely lateralized domain-general visuospatial neglect were identified. Conversely, all cases of egocentric neglect dyslexia were found in the presence of domain-general visuospatial neglect. These findings suggest that allocentric neglect dyslexia cannot be fully understood as a consequence of visuospatial neglect. In contrast, we found no evidence for a dissociation between egocentric neglect dyslexia and visuospatial neglect. These findings highlight the need for new, neglect dyslexia specific rehabilitation strategies to be designed and tested.

Evidence for Cognitive Deficits in X-Linked Charcot-Marie-Tooth Disease.

OBJECTIVE: X-linked Charcot-Marie-Tooth disease (CMTX) is an hereditary neuropathy caused by mutations in GJB1 coding for connexin-32, found in Schwann cells, but also expressed in oligodendrocytes. Reports have identified CNS involvement in CMTX, but no systematic study of cognitive function has been published. METHODS: We assessed 24 CMTX patients (13 males; 9GJB1 mutations) with a comprehensive neuropsychological battery, including tests of memory, language, and executive functions. RESULTS: No differences in cognitive performance were observed between males and females. A case-by-case investigation revealed selective deficits in individual patients. One subgroup (29%) demonstrated executive abnormalities; and a non-overlapping subgroup (29%), prominent reading (decoding) abnormalities. CONCLUSIONS: The present data provide evidence for cognitive deficits in CMTX. Emerging neuropsychological patterns are also discussed.