Specific Learning Disabilities and Emotional-Behavioral Difficulties: Phenotypes and Role of the Cognitive Profile.

Specific Learning Disabilities (SLD) are often associated with emotional-behavioral problems. Many studies highlighted a greater psychopathological risk in SLD, describing both internalizing and externalizing problems. The aims of this study were to investigate the emotional-behavioral phenotype through the Child Behavior Checklist (CBCL), and evaluate the mediating role of background and cognitive characteristics on the relationship between CBCL profile and learning impairment in children and adolescents with SLD. One hundred and twenty-one SLD subjects (7-18 years) were recruited. Cognitive and academic skills were assessed, and parents completed the questionnaire CBCL 6-18. The results showed that about half of the subjects manifested emotional-behavioral problems with a prevalence of internalizing symptoms, such as anxiety and depression, over externalizing ones. Older children showed greater internalizing problems than younger ones. Males have greater externalizing problems compared to females. A mediation model analysis revealed that learning impairment is directly predicted by age and familiarity for neurodevelopmental disorders and indirectly via the mediation of the WISC-IV/WAIS-IV Working Memory Index (WMI) by the CBCL Rule-Breaking Behavior scale. This study stresses the need to combine the learning and neuropsychological assessment with a psychopathological evaluation of children and adolescents with SLD and provides new interpretative insights on the complex interaction between cognitive, learning, and emotional-behavioral phenotypes.

Sex differences in early language delay and in developmental language disorder.

Developmental language disorder (DLD) is a neurodevelopmental condition, occurring in about 3% to 7% of preschoolers, that can impair communication and negatively impact educational and social attainments, in spite of adequate neurological, cognitive, emotional, social development, and educational opportunities for language learning. Significant risk factors for DLD are male sex, familial history of early language delay, low parental education, and various perinatal factors. A strong sex effect with a higher prevalence of language delay and DLD in males than in females has been consistently reported. Neurobiological and environmental risk factors, interacting with each other, are probably responsible for the phenotypic expression of DLD. The aim of this brief review is to further the knowledge of the role of sex in early language delay and DLD by analyzing the evidence from four significant sources: epidemiological studies, studies on twins, family aggregation studies, and studies on sex chromosome trisomies. Data pertaining only to sex differences (biological and physiological characteristics of females and males) will be analyzed. Studies on family aggregations and twins confirm the role of genetic factors and of sex in determining language abilities and disabilities, but genes alone do not determine outcomes. Sex chromosome trisomies represent a unique example of the relationship between a genetic alteration and a language disorder. Clarification of how sex acts in determining DLD could provide new information on early risk factors and, thus, contribute to improve diagnosis and clinical management.

Differences and Commonalities in Children with Childhood Apraxia of Speech and Comorbid Neurodevelopmental Disorders: A Multidimensional Perspective.

Childhood apraxia of speech (CAS) is a motor speech disorder often co-occurring with language impairment and complex neurodevelopmental disorders. A cohort of 106 children with CAS associated to other neurodevelopmental disorders underwent a multidimensional investigation of speech and language profiles, chromosome microarray analysis and structural brain magnetic resonance (MR). Our aim was to compare the clinical profiles of children with CAS co-occurring with only language impairment with those who, in addition to language impairment, had other neurodevelopmental disorders. Expressive grammar was impaired in the majority of the sample in the context of similar alterations of speech, typical of the core symptoms of CAS. Moreover, children with complex comorbidities also showed more severe and persistent receptive language deficits. About 25% of the participants harbored copy number variations (CNVs) already described in association to neurodevelopmental disorders. CNVs occurred more frequently in children with complex comorbidities. MR structural/signal alterations were found in a small number of children and were of uncertain pathogenic significance. These results confirm that CAS needs multidimensional diagnostic and clinical management. The high frequency of language impairment has important implications for early care and demands a personalized treatment approach in which speech and language goals are consistently integrated.

Implicit learning in children with Childhood Apraxia of Speech.

BACKGROUND: Childhood Apraxia of Speech is a severe and persistent clinical subtype of Speech Sound Disorder. Given the difficulties in the acquisition, programming and control of the movements underlying speech and the slowdown in a wide range of non-linguistic skills, the difficulty in implicit learning of sequential information could play a role in the disorder, contributing to understand its etiopathological mechanisms and behavioral manifestations. AIMS: The present study was aimed at investigating implicit learning in children with Childhood Apraxia of Speech. METHODS AND PROCEDURES: Twenty-five children with Childhood Apraxia of Speech, aged between 4 and 12 years, were matched for IQ and age to a control group of 25 typically developing children. Implicit learning of participants was assessed by Serial Reaction Time Task. OUTCOME AND RESULTS: Children with Childhood Apraxia of Speech did not show implicit learning, as documented by the absence of differences between reaction times in the sequenced block and the random block, usually considered as a measure of implicit learning effect. CONCLUSION AND IMPLICATIONS: Our results underline an implicit learning deficit in children with Childhood Apraxia of Speech, supporting the concept of a disorder not only confined to the speech domain, but also involving non-linguistic skills, in a composite and complex picture.

Relationship among Connectivity of the Frontal Aslant Tract, Executive Functions, and Speech and Language Impairment in Children with Childhood Apraxia of Speech.

Childhood apraxia of speech (CAS) is a subtype of motor speech disorder usually co-occurring with language impairment. A supramodal processing difficulty, involving executive functions (EFs), might contribute to the cognitive endophenotypes and behavioral manifestations. The present study aimed to profile the EFs in CAS, investigating the relationship between EFs, speech and language severity, and the connectivity of the frontal aslant tract (FAT), a white matter tract involved in both speech and EFs. A total of 30 preschool children with CAS underwent speech, language, and EF assessments and brain MRIs. Their FAT connectivity metrics were compared to those of 30 children without other neurodevelopmental disorders (NoNDs), who also underwent brain MRIs. Alterations in some basic EF components were found. Inhibition and working memory correlated with speech and language severity. Compared to NoND children, a weak, significant reduction in fractional anisotropy (FA) in the left presupplementary motor area (preSMA) FAT component was found. Only speech severity correlated and predicted FA values along with the FAT in both of its components, and visual-spatial working memory moderated the relationship between speech severity and FA in the left SMA. Our study supports the conceptualization of a composite and complex picture of CAS, not limited to the speech core deficit, but also involving high-order cognitive skills.

Training RAN or reading? A telerehabilitation study on developmental dyslexia.

Rehabilitation procedures recommended for developmental dyslexia (DD) are still not fully defined, and only few studies directly compare different types of training. This study compared a training (Reading Trainer) working on the reading impairment with one (Run the RAN) working on the rapid automatized naming (RAN) impairment, one of the main cognitive deficits associated with DD. Two groups of DD children (N = 45) equivalent for age, sex, full IQ, and reading speed were trained either by Reading Trainer (n = 21) or by Run the RAN (n = 24); both trainings required an intensive home exercise, lasting 3 months. Both trainings showed significant improvements in reading speed and accuracy of passages and words. Bypassing the use of alphanumeric stimuli, but empowering the cognitive processes underlying reading, training RAN may be a valid tool in children with reading difficulties opening new perspectives for children with severe impairments or, even, at risk of reading difficulties.

Four years follow up of ACY1 deficient patient and pedigree study.

Aminoacylase 1 deficiency (ACY1D) is a rare inborn error of metabolism characterized by increased urinary excretion of N-acetylated amino acids. Clinical phenotypes of 15 known patients with ACY1 deficiency have been described up to now. Findings are greatly variable, ranging from normality to relevant neurological and psychiatric impairments, but clinical follow up has been rarely reported. To partially fill this gap, we present a detailed clinical description and the outcome four years post-diagnosis of a patient already described, with mild intellectual disability, language delay, autistic traits and compound heterozygous mutations in ACY1.

Telerehabilitation in developmental dyslexia: methods of implementation and expected results.

BACKGROUND: Developmental Dyslexia is a disorder, highly frequent in the school population, for which the recommended rehabilitation procedures are not well defined. This study aimed to automatize reading decoding skills by using an innovative system for rehabilitation, based on a telerehabilitation method. It requires an intensive home-exercise with the supervision, by web, of the clinician. The study had three main aims: to diffuse knowledge on new methods for rehabilitation of reading difficulties; to verify whether an intensive and simplified exercise, targeted to the automation of reading, is suitable for different subgroups of dyslexic children; to define the treatment effects on basic cognitive functions underlying reading. METHODS: Twenty-five children, grouped according to the neuropsychological and anamnestic profiles, took part to the treatment by the software Reading Trainer®. RESULTS: Both speed and accuracy of reading decoding increased significantly after treatment, independently from the functional neuropsychological profile or the history of oral language delay. These changes were specific to decoding and not associated with improvements in reading comprehension or spelling skills. However, there was a "cascade effect" of the treatment efficacy on those basic cognitive functions considered precursors of the ability to read, with significant improvements in rapid lexical access, phonological processing and visual attention. CONCLUSIONS: This study provides information on the efficacy of new tools for telerehabilitation of specific reading disorders.

Fifteen-year follow-up of Italian families affected by arginine glycine amidinotransferase deficiency.

BACKGROUND: Arginine:glycine amidinotransferase deficiency (AGAT-d) is a very rare inborn error of creatine synthesis mainly characterized by absence of brain Creatine (Cr) peak, intellectual disability, severe language impairment and behavioural disorder and susceptible to supplementary Cr treatment per os. Serial examinations by magnetic resonance spectroscopy are required to evaluate Cr recovery in brain during treatment of high doses of Cr per os, which have been proved beneficial and effective in treating main clinical symptoms. A long term study with detailed reports on clinical, neurochemical and neuropsychological outcomes of the first Italian patients affected by AGAT-d here reported can represent a landmark in management of this disorder thus enhancing medical knowledge and clinical practice. RESULTS: We have evaluated the long term effects of Cr supplementation management in four Italian patients affected by AGAT-d, correlating specific treatments with serial clinical, biochemical and magnetic resonance spectroscopy examinations as well as the neuropsychological outcome by standardized developmental scales. Consecutive MRS examinations have confirmed that Cr depletion in AGAT-d patients is reversible under Cr supplementation. Cr treatment is considered safe and well tolerated but side effects, including weight gain and kidney stones, have been reported. CONCLUSIONS: Early treatment prevents adverse developmental outcome, while patients diagnosed and treated at an older age showed partial but significant cognitive recovery with clear improvements in adaptive functioning.

The contribution of discrete-trial naming and visual recognition to rapid automatized naming deficits of dyslexic children with and without a history of language delay.

Children with Developmental Dyslexia (DD) are impaired in Rapid Automatized Naming (RAN) tasks, where subjects are asked to name arrays of high frequency items as quickly as possible. However the reasons why RAN speed discriminates DD from typical readers are not yet fully understood. Our study was aimed to identify some of the cognitive mechanisms underlying RAN-reading relationship by comparing one group of 32 children with DD with an age-matched control group of typical readers on a naming and a visual recognition task both using a discrete-trial methodology, in addition to a serial RAN task, all using the same stimuli (digits and colors). Results showed a significant slowness of DD children in both serial and discrete-trial naming (DN) tasks regardless of type of stimulus, but no difference between the two groups on the discrete-trial recognition task. Significant differences between DD and control participants in the RAN task disappeared when performance in the DN task was partialled out by covariance analysis for colors, but not for digits. The same pattern held in a subgroup of DD subjects with a history of early language delay (LD). By contrast, in a subsample of DD children without LD the RAN deficit was specific for digits and disappeared after slowness in DN was partialled out. Slowness in DN was more evident for LD than for noLD DD children. Overall, our results confirm previous evidence indicating a name-retrieval deficit as a cognitive impairment underlying RAN slowness in DD children. This deficit seems to be more marked in DD children with previous LD. Moreover, additional cognitive deficits specifically associated with serial RAN tasks have to be taken into account when explaining deficient RAN speed of these latter children. We suggest that partially different cognitive dysfunctions underpin superficially similar RAN impairments in different subgroups of DD subjects.

Long-term reading and spelling outcome in Italian adolescents with a history of specific language impairment.

Specific language impairment (SLI) diagnosed in the pre-school years is frequently associated with reading and writing difficulties at school age. The nature of this relationship is unclear, despite the availability of a large number of studies, mostly on English speaking children. Phonological processing deficits have been considered the prominent cause of both difficulties. However recent findings in both children with SLI and in children with reading difficulties are not easily accommodated within a single dimensional model explaining the relationship between oral and written language deficits. Our study focuses on the long-term reading and spelling outcome in relation to preschool oral language skills in a group of Italian adolescents with a documented history of SLI. Sixteen Italian adolescents diagnosed as SLI at our Hospital in the pre-school years and 32 normal controls were submitted to an extensive assessment of oral and written language skills. At a group level SLI adolescents had weak oral and written language skills in almost all tests. Results show that reading difficulties have some features in common with those of Italian developmental dyslexics but also have distinct characteristics, since reading accuracy and written comprehension, usually relatively spared in Italian developmental dyslexics, were impaired in adolescents with SLI. Longitudinal analyses showed that expressive morpho-syntactic and lexical abilities at pre-school age were the oral language skills that best predicted reading and spelling outcomes in adolescents with SLI. However, also children with severe phonological impairment in the absence of other oral language deficits showed later literacy difficulties, although less severe and mainly limited to reading accuracy. Our study supports the notion that there is a complex relationship between oral and written language difficulties which may change at different developmental time points, not captured by a single deficit model, but best conceptualized considering multiple interactions between language skills and literacy abilities.

Non-word repetition in children with specific language impairment: a deficit in phonological working memory or in long-term verbal knowledge?

In this study we investigated the effects of long-term memory (LTM) verbal knowledge on short-term memory (STM) verbal recall in a sample of Italian children affected by different subtypes of specific language impairment (SLI). The aim of the study was to evaluate if phonological working memory (PWM) abilities of SLI children can be supported by LTM linguistic representations and if PWM performances can be differently affected in the various subtypes of SLI. We tested a sample of 54 children affected by Mixed Receptive-Expressive (RE), Expressive (Ex) and Phonological (Ph) SLI (DSM-IV - American Psychiatric Association, 1994) by means of a repetition task of words (W) and non-words (NW) differing in morphemic structure [morphological non-words (MNW), consisting of combinations of roots and affixes - and simple non-words - with no morphological constituency]. We evaluated the effects of lexical and morpho-lexical LTM representations on STM recall by comparing the repetition accuracy across the three types of stimuli. Results indicated that although SLI children, as a group, showed lower repetition scores than controls, their performance was affected similarly to controls by the type of stimulus and the experimental manipulation of the non-words (better repetition of W than MNW and NW, and of MNW than NW), confirming the recourse to LTM verbal representations to support STM recall. The influence of LTM verbal knowledge on STM recall in SLI improved with age and did not differ among the three types of SLI. However, the three types of SLI differed in the accuracy of their repetition performances (PMW abilities), with the Phonological group showing the best scores. The implications for SLI theory and practice are discussed.

Hemispheric specialization for language in children with different types of specific language impairment.

The aim of the study was to investigate whether children with Specific Language Impairment (SLI) show reduced left hemisphere specialization for language and, if so, whether it is associated with a deficit in phonological encoding and a specific type of SLI (Mixed Receptive-Expressive, Expressive, Phonological). We adopted two dichotic listening paradigms, which differed in the phonological similarity of the presented words (Fused and Non-Fused dichotic words tests), as well as a phonological working memory test. Participants included 34 pre-school and school age children affected by SLI. On the dichotic tests, as a group the children with SLI showed a reduced pattern of left hemisphere specialization for language compared to age-matched normal children, with significant differences only in the Fused condition. However, the pattern of hemispheric specialization varied depending on the type of SLI, with reduced left hemisphere specialization in the Expressive type and, to a lesser extent, in the Phonological type of SLI, but not in the Receptive-Expressive type. The three subgroups also differed in phonological processing abilities and the incidence of a positive family history for language disorders: the Receptive-Expressive group performed worse on the working memory and dichotic tests and the Expressive and Phonological groups presented high frequency for familial language disorder. These results suggest that different subtypes of SLI are not different manifestations of the same underlying disorder, but represent pathological conditions that have distinct markers both at the behavioral and neurofunctional level.

A case of amnesia at an early age.

A dissociation between short- and long-term memory (LTM) and between the episodic and the semantic component of LTM is reported in a young girl who became amnesic at the age of 6 after an episode of acute encephalopathy resulting in bilateral frontal, insular, thalamic, ponto-mesencephalic, hippocampal and temporal lesions, as documented by MRI. The girl became amnesic a few months after starting school. A follow-up investigation showed that she was able to learn to read, write and acquire number facts and procedures and to improve her semantic knowledge. Our results show that the features of adult amnesia can also be found in children and that new semantic knowledge can be acquired in spite of an anterograde memory deficit. This dissociation does not agree with theories viewing long-term declarative memory as a unitary process mediated by the hippocampal system, but supports recent hypotheses that the acquisition of semantic knowledge is independent from episodic memory processes, and takes place through spared cortical regions subjacent to the hippocampi (Vargha-Khadem et al., 1997).