Sleep disturbances in specific learning disorders: a qualitative and quantitative investigation.

BACKGROUND: The literature reports a significant association between sleep disorders and learning disabilities. Nevertheless, not all children with learning disorders have sleep alterations, and which sleep characteristics are associated with which learning difficulty is still unknown. The study aimed at acquiring new information on the relation between sleep disturbances or habits and the learning profiles of children with a specific learning disorder (SLD). METHODS: The Sleep Disturbance Scale for Children (SDSC) and an actigraph (the FitBit-Flex, FB-F) were used in 26 and 16 SLD children respectively; all children were also assessed for learning skills. RESULTS: Although parents' reports at the SDSC did not differentiate SLD from typical readers, the awakening, respiratory and arousal disturbances at the SDSC correlated with sleep duration at the FB-F. Sleep alterations at the FB-F actigraph characterize SLD with literacy difficulties: children with reading decoding difficulties showed shorter minimum amount of sleep than typical children, and severe SLDs showed shorter maximum sleep duration and a higher number of awakenings in comparison to SLDs with mild learning deficits. CONCLUSIONS: Mild alterations in the amount, duration and quality of sleep may characterize children with learning disorders and actigraphy proves to be a useful tool in starting the individual monitoring of sleep in these populations.

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.

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.

Spelling Impairments in Italian Dyslexic Children with and without a History of Early Language Delay. Are There Any Differences?

Language delay is considered a frequent antecedent of literacy problems and both may be linked to phonological impairment. However, while several studies have examined the relationship between language delay and reading impairment, relatively few have focused on spelling. In this study, spelling performance of 28 children with developmental dyslexia (DD), 14 children with a history of language delay (LD), and 14 children without (NoLD) and 28 control participants were examined. Spelling was investigated by a writing to dictation task that included orthographically regular stimuli (word and non-words), as well as words with unpredictable transcription. Results indicated that all dyslexic participants underperformed compared to controls on both regular and unpredictable transcription stimuli, but LD performance was generally the worst. Moreover, spelling impairment assumed different characteristics in LD and NoLD children. LD children were more sensitive to acoustic-to-phonological variables, showing relevant failure especially on stimuli containing geminate consonants but also on polysyllabic stimuli and those containing non-continuant consonants. Error analysis confirmed these results, with LD children producing a higher rate of phonological errors respect to NoLD children and controls. Results were coherent with the hypothesis that among dyslexic children, those with previous language delay have more severe spelling deficit, suffering from defective orthographic lexical acquisition together with long-lasting phonological difficulties.

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.

The process and criteria for diagnosing specific learning disorders: indications from the Consensus Conference promoted by the Italian National Institute of Health.

A Consensus Conference on Specific Learning Disorders has been promoted by the Italian National Institute of Health (Istituto Superiore di Sanità, ISS). The Consensus Conference consisted in a systematic review of the international literature addressing the issues of diagnosis, risk factors and prognosis, treatment, service delivery and organizational models for Specific Learning Disorders (reading, spelling/writing, calculation). Selected papers were examined by a group of Evaluators and then discussed by a Scientific and Technical Committee, whose conclusions were examined and approved by a Jury Panel. The part on diagnostic issues is presented here, encompassing a systematic discussion of the use and appropriateness of diagnostic criteria, parameters, tasks and psychometric indexes as illustrated in the literature, and providing recommendations for clinical practice. Special attention has been devoted to the collection, analysis and discussion of published data concerning languages with transparent orthography. Controversial issues such as discrepancy criteria, role of reading comprehension and importance of accuracy and fluency are discussed.

Body knowledge in brain-damaged children: a double-dissociation in self and other's body processing.

Bodies are important element for self-recognition. In this respect, in adults it has been recently shown a self vs other advantage when small parts of the subjects' body are visible. This advantage is lost following a right brain lesion underlying a role of the right hemisphere in self body-parts processing. In order to investigate the bodily-self processing in children and the development of its neuronal bases, 57 typically developing healthy subjects and 17 subjects with unilateral brain damage (5 right and 12 left sided), aged 4-17 years, were submitted to a matching-to-sample task. In this task, three stimuli vertically aligned were simultaneously presented at the centre of the computer screen. Subjects were required which of two stimuli (the upper or the lower one) matched the central target stimulus, half stimuli representing self and half stimuli representing other people's body-parts and face-parts. The results showed that corporeal self recognition is present since at least 4 years of age and that self and others' body parts processing are different and sustained by separate cerebral substrates. Indeed, a double dissociation was found: right brain damaged patients were impaired in self but not in other people's body parts, showing a self-disadvantage, whereas left brain damaged patients were impaired in others' but not in self body parts processing. Finally, since the double dissociation self/other was found for body-parts but not for face parts, the corporal self seems to be dissociated for body and face-parts. This opens the possibility of independent and lateralized functional modules for the processing of self and other body parts during development.

How many functional brains in developmental dyslexia? When the history of language delay makes the difference.

BACKGROUND: Clinical manifestations of developmental dyslexia (DD) are greatly variable, suggesting complex underlying mechanisms. It was recently advanced that the characteristics of DD in Italian, a language with shallow orthography, are influenced by a positive history for language delay. OBJECTIVE: We explored this hypothesis by studying in Italian individuals with DD (i) the brain representation of phonological processing with functional magnetic resonance imaging and (ii) the correlation between the patterns of activation and the presence/absence of previous language delay. METHOD: Thirteen individuals with DD and 13 controls participated in the functional magnetic resonance imaging experiment consisting of a rhyme-generation task. RESULTS: Individuals with DD showed a reduced activation of phonological processing areas of the left hemisphere, such as the middle frontal gyrus, the precuneus, and the inferior parietal lobule, and in particular the superior temporal gyrus. Furthermore, patients with a history of language delay had reduced activation in the left inferior and medial frontal gyrus, that was associated with worse reading and phonological accuracy than patients with normal language development. CONCLUSIONS: Neurofunctional profiles of Italian individuals with DD are correlated to the history of language delay, suggesting that the relatively better behavioral profiles observed in individuals without a history of language delay are associated with a major activation of frontal networks normally involved in phonological working memory.

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.

Reading and spelling disabilities in children with and without a history of early language delay: a neuropsychological and linguistic study.

Language delay is a frequent antecedent of literacy problems, and both may be linked to phonological impairment. Studies on developmental dyslexia have led to contradictory results due to the heterogeneity of the pathological samples. The present study investigated whether Italian children with dyslexia showed selective phonological processing deficits or more widespread linguistic impairment and whether these deficits were associated with previous language delay. We chose 46 children with specific reading deficits and divided them into two groups based on whether they had language delay (LD) or not (NoLD). LD and NoLD children showed similar, severe deficits in reading and spelling decoding, but only LD children showed a moderate impairment in reading comprehension. LD children were more impaired in phonological working memory and phonological fluency, as well as in semantic fluency, grammatical comprehension, and verbal IQ. These findings indicate the presence of a moderate but widespread linguistic deficit (not limited to phonological processing) in a subset of dyslexic children with previous language delay that does not generalize to all children with reading difficulties.

Subtypes of developmental dyslexia in transparent orthographies: a comment on Lachmann and Van Leeuwen (2008).

Lachmann and Van Leeuwen (2008) proposed two diagnostic subtypes of developmental dyslexia in a language with transparent orthography (German). The classification was based on reading time, rather than reading errors, for lists of words and nonwords. The two subtypes were "frequent-word reading impaired" (FWRI) and "nonword reading impaired" (NWRI). Notably, FWRI were very slow in reading high-frequency words but as fast as controls in reading nonwords; ca. one-third of these children showed this "reversed lexicality effect" in a particularly marked fashion (i.e., read nonwords two to three times faster than high-frequency words). Since Italian is a highly transparent language, we applied this classification to 87 third- and sixth-grade dyslexics from various previously published studies. Some children showed a marked lexicality effect, while others showed small or no difference between word and nonword reading speed. However, regardless of stimulus length, grade and presence/absence of a previous language delay, no child showed a marked reversed lexicality effect; more generally, no child could be classified as FWRI. These findings indicate that the search for subtypes of developmental dyslexia in transparent orthographies still constitutes an open question.

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.

Naming speed and visual search deficits in readers with disabilities: evidence from an orthographically regular language (Italian).

The study examined rapid automatized naming (RAN) in 42 children with reading disabilities and 101 control children-all native speakers of Italian, a language with shallow orthography. Third-, 5th- and 6th-grade children were given a RAN test that required rapid naming of color, object, or digit matrices. A visual search test using the same stimulus material (but not requiring a verbal response) and an oral articulation test were also given. Readers with disabilities performed worse than controls on the RAN test. This effect was larger in higher grades than in lower ones. Readers with disabilities were also slower than controls in performing the visual search test. The pattern of results for the RAN test held constant when the visual search performance was partialed out by covariance analysis, indicating the independence of the 2 deficits. The 2 groups did not differ for articulation rate. Finally, analysis of the pattern of intercorrelations indicated that reading speed was most clearly related to RAN, particularly in the group with reading disabilities. The results extend observations of RAN effects on reading deficits to Italian, an orthographically shallow language.

Do phonologic and rapid automatized naming deficits differentially affect dyslexic children with and without a history of language delay? A study of Italian dyslexic children.

OBJECTIVE: The study aims to verify whether phonologic and rapid automatized naming (RAN) deficits are present and associated in Italian dyslexic children and whether they differentially affect dyslexics with and without a history of previous language delay (LD). BACKGROUND: According to the phonologic core deficit hypothesis, dyslexia may stem from impairment of the representation and manipulation of phonemes and may be closely associated with oral language deficits. However, deficits in tasks not requiring fine-grained phonologic representations, such as RAN, have also been described in dyslexic children. METHODS: Thirty-seven children were selected on the basis of a reading deficit and were assigned to 2 groups according to whether or not they had a history of early LD as determined retrospectively by parental report. A battery of reading and writing, verbal working memory, metaphonologic, RAN, and visual search tests were administered. RESULTS: RAN deficits were shared by most dyslexics (with and without a history of LD), whereas phonologic deficits were mainly associated with a previous LD. This last condition did not result in a more profound impairment of reading and writing decoding skills. CONCLUSION: In a shallow orthography such as Italian, RAN, not phonologic deficits, may represent the main cognitive marker of developmental dyslexia.

Spatial and motion integration in children with autism.

Neuropsychological and psychophysical studies report controversial results regarding local-global visual processing and motion perception in autism. Here, we investigate contour integration and motion perception in an accurately diagnosed sample of autistic children, using low-level psychophysical tasks. We measured detection thresholds for a closed chain of Gabor patches, for different values of inter-element distance and we measured coherency thresholds of optic flow motion stimuli. Both experiments show comparable performances between autistics and normal subjects, demonstrating no evidence of early perceptual integration deficits. Some improvement in performance with age is detected in both groups.

Rapid naming, not cancellation speed or articulation rate, predicts reading in an orthographically regular language (Italian).

This study examined the influence of rapid automatization naming (RAN) measures on various parameters of reading performance in children who were native speakers of a language with a shallow orthography (Italian). Participants included 281 children enrolled in first-to-sixth grade. They were given a Naming test, in which they had to name rapidly matrices of colors, objects, or digits, a Cancellation test, using the same stimulus materials, and an oral Articulation test. Performance on all tests improved steadily across ages tested. Performance on the Naming test, but not on the Cancellation and Articulation tests, predicted speed and accuracy in reading; none of these measures reliably predicted the reading comprehension measure. Data on a Blending test were also available for a subsample of first- and third-graders. Both RAN and phonological ability contributed independently to the prediction of reading ability (accuracy and speed) in these participants. The results extend observations on RAN to an orthographically shallow language (Italian) and suggest an element of continuity between languages with opaque and transparent orthographies.

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.

Abnormal phonologic processing in familial lateral temporal lobe epilepsy due to a new LGI1 mutation.

PURPOSE: Autosomal dominant lateral temporal lobe epilepsy (ADLTLE) is a rare familial epilepsy with onset in adolescence or early adulthood, associated with mutations of LGI1 in most families. We describe the clinical, neuropsychological, and molecular genetic study of a new ADLTLE Italian family. METHODS: A four-generation family from Sardinia was studied. Clinical, neuropsychological, and genetic analysis were performed in eight living affected family members. RESULTS: Nine family members had seizures over four generations; four of them had auditory auras and aphasia followed by secondarily generalized tonic-clonic seizures (SGTCs). One individual in addition had visual symptoms, and one family member had only vertigo followed by SGTCs. The side of seizure onset could not be determined in these five patients with focal seizures. The proband had febrile and afebrile tonic-clonic seizures. Two family members had only febrile seizures. Inheritance was autosomal dominant with 59% penetrance. Genetic molecular analysis showed a new LGI1 missense mutation causing a Leu154Pro substitution in six affected and one unaffected individuals. Dichotic listening performance was abnormal in four affected individuals compared with controls. Fluency and lexical abilities also were pathological in three patients. These findings showed that in patients, the left temporal lobe was less specialized in the auditory processing function than in controls. CONCLUSIONS: In this ADLTLE family, both seizure semiology and neuropsychological findings point to a lateral temporal lobe dysfunction. The newly identified LGI1 mutation might underlie both the seizure disorder and the neuropsychological deficits.

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).

Timing and type of congenital brain lesion determine different patterns of language lateralization in hemiplegic children.

Cerebral lateralization for language has been assessed by means of the Fused Dichotic Words Test in 26 hemiplegic children (mean age 7 years 2 months) with congenital focal brain damage (ten with left, seven with right and nine with bilateral lesions). The specific aim of the study was to investigate the relation between lesion characteristics (side, size and localization) at high field, multiple plane MRI and the pattern of language lateralization at the dichotic test. Significant side and site effects were found at group level; in children with lesions of the left hemisphere a left ear advantage (LEA) was found, while children with right lesions had the expected right ear advantage (REA). Analysis of individual data, however, revealed that type of lesion, cortical-subcortical or periventricular, occurring at term or preterm age, respectively, may be the primary factor responsible for inter versus intrahemispheric organization of language after congenital brain lesions. Only when the left lesions involved cortical-subcortical regions encroaching the temporal lobe and occurred at term age, was language reorganized in the right hemisphere; when lesions (whether left or right) involved only the periventricular white matter and occurred at preterm age, language was lateralized in the left hemisphere. Our results provide evidence that within 'congenital hemiplegias', strictly defined as hemiplegias whose causal lesion occurs before the end of the neonatal period, different recovery mechanisms are at work, depending on the type of brain lesion (neuropathology) which largely depends on the timing of insult (preterm vs. term period).