Principal identifying features of the syndrome of nonverbal learning disabilities in children

Visual-Motor Integration Deficits in 3q29 Deletion Syndrome

3q29 deletion syndrome (3q29del) is associated with neuropsychiatric and neurodevelopmental phenotypes. We previously reported that graphomotor weakness is present in up to 78% of individuals with 3q29del. We have now explored nuances of the graphomotor phenotype and its association with other comorbidities in this population. Participants were recruited from the online 3q29 registry (3q29deletion.org) for two days of deep phenotyping. 32 individuals with 3q29del (62.5% male) were evaluated with the Beery-Buktenica Developmental Test of Visual-Motor Integration (VMI) to assess visual-motor integration. Participants were also evaluated with measures of cognitive ability, executive function, adaptive behavior, and school function. Males with 3q29del performed significantly worse than females on the VMI and Motor Coordination subtest. VMI performance was significantly associated with ADHD diagnosis and cognitive ability. Compared to published data from individuals with 22q11.2 deletion syndrome, individuals with 3q29del showed significantly more impairment. The 3q29 deletion is associated with substantial deficits in visual-motor integration, Visual Perception, and Motor Coordination. Our data suggests that 3q29del may qualify as a nonverbal learning disability. Future studies should assess whether individuals with 3q29del would benefit from early interventions, including occupational therapy.

Editorial: Time to Recognize Nonverbal Learning Disability to Foster Advances in Its Research

The definitions of most of the currently recognized neurodevelopmental disorders and the criteria used to identify them have seen important changes since their inclusion in diagnostic classification systems (see, for instance, how the definitions of specific learning disorders and autism spectrum disorder (ASD) have been revised in successive versions of DSM). As is the case with many other mental conditions, our understanding of neurodevelopmental disorders is continuously being updated in the light of new research findings. However, this has not been the case for nonverbal learning disability. More than 50 years since it was first described,¹ there is still no consensus on the merits of identifying it as a separate disorder or using a clear and acknowledged diagnostic label. Instead of trying to establish why nonverbal learning disability has yet to be included in the diagnostic manuals, this editorial examines why recognized criteria for the condition would improve research in this field and avoid the negative consequences of continuing to conduct research without adopting shared criteria.

Systematic Review: Nonverbal Learning Disability

OBJECTIVE

To summarize the current state of the research literature on nonverbal learning disability (NVLD), including criteria used to define NVLD in research contexts and the quality of the extant research; and to determine what research can tell us about ways in which NVLD is distinct from DSM neurodevelopmental disorders and typical development.

METHOD

A systematic search of 7 databases was conducted to identify research on NVLD published through February 2019. Criteria used to define NVLD were extracted from identified studies and sorted by category. Each study was assessed for risk of bias and rated "good," "fair," or "poor;" findings from studies rated good or fair were summarized.

RESULTS

A total of 61 articles (63 studies) met inclusion criteria. There was great heterogeneity in the criteria used to define NVLD. Deficits in visuospatial ability/intelligence was the most common criterion used, followed by discrepancy between verbal and nonverbal intelligence (VIQ>PIQ split of 10 or greater). All studies were cross-sectional and most included small, poorly described samples. Most studies focused on children and young adolescents. Eight studies were rated as good, 42 as fair, and 13 as poor. Review of results from the 50 good or fair studies suggest that there is sufficient evidence that youths with NVLD (as defined by significant deficits in visuospatial abilities) can be clearly differentiated from their typically developing peers, those with verbal learning disorders, and from other clinical groups (eg, individuals with high functioning autism).

CONCLUSION

A standard set of criteria for determining an NVLD diagnosis would greatly improve research studies and the possibility of inclusion in the DSM and the International Classification of Diseases.

Alternatives to Gold Standard Diagnostic Tools for Distinguishing "Natural Kinds" on the Autism Spectrum

Next-generation sequencing techniques have accelerated the discovery of rare mutations responsible for autism spectrum disorder (ASD) in genes involved in a large number of physiological processes, including the control of gene expression, chromatin remodeling, signaling pathways, synaptic scaffolding, neurotransmitter receptors, and lipid metabolism. Genetic diagnosis provides subjects with an explanation of the cause of their disorder. However, it does not, or at least does not yet, shed light on the psychopathological phenomena specific to the individual. It could be hypothesized that each physiological impact of a mutation corresponds to a specific psychopathological phenomenon of ASD, i.e., "a psychopathological natural kind". We discuss here the difficulties identifying this specificity of underlying psychopathology in individuals with ASD due to a rare mutation with a major effect. A comparison of Newson's pathological demand avoidance and Wing's Asperger's syndrome with Asperger's autistic psychopathy highlights different ways of approaching psychopathological descriptions and diagnosis, by focusing on either common or unusual features. Such a comparison calls into question the principles of clinical research recommended by Falret for characterizing "disease individuality" of ASD due to a rare mutation.

A comparative study of the neuropsychiatric and neurocognitive phenotype in two microdeletion syndromes: Velocardiofacial (22q11.2 deletion) and Williams (7q11.23 deletion) syndromes

Purpose:

22q11.2 deletion syndrome (22q11.2DS) and Williams syndrome (WS) are common neurogenetic microdeletion syndromes. The aim of the present study was to compare the neuropsychiatric and neurocognitive phenotypes of 22q11.2DS and WS.

Methods:

Forty-five individuals with 22q11.2DS, 24 with WS, 22 with idiopathic developmental disability (DD) and 22 typically developing (TD) controls were compared for the rates of psychiatric disorders as well as cognitive executive and visuospatial functions.

Results:

We found that while anxiety, mood and disruptive disorders had an equally high prevalence among individuals with 22q11.2DS, WS and DDs, the 22q11.2DS group had the highest rates of psychotic disorders and the WS group had the highest rates of specific phobia. We also found that the WS group demonstrated more severe impairments in both executive and visuospatial functions than the other groups. WS and 22q11.2DS subjects had worse Performance-IQ than Verbal-IQ, a feature typical of non-verbal learning disorders.

Conclusion:

These findings offer a wide perspective on unique versus common phenotypes in 22q11.2DS and WS.

Estimated Prevalence of Nonverbal Learning Disability Among North American Children and Adolescents

IMPORTANCE

Nonverbal learning disability (NVLD) is a neurodevelopmental disorder characterized by deficits in visual-spatial processing but not in reading or verbal ability; in addition, problems in math calculation, visual executive functioning, fine-motor skills, and social skills are often present. To our knowledge, there are no population-based estimates of the prevalence of NVLD in community samples.

OBJECTIVE

To estimate the prevalence of the NVLD cognitive profile in 3 independent samples of children and adolescents from studies centered around brain imaging in the US and Canada.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study used data from 2 samples recruited from the community and overselected for children with psychiatric disorders (Healthy Brain Network [HBN], January 1, 2015, to December 31, 2019, and Nathan Kline Institute-Rockland Sample [NKI], January 1, 2011, to December 31, 2018) and 1 community-ascertained population sample (Saguenay Youth Study [SYS], January 1, 2003, to December 31, 2012) overselected for active maternal smoking during pregnancy.

MAIN OUTCOMES AND MEASURES

Prevalence of NVLD. Criteria for NVLD were based on clinical records of deficits in visual-spatial reasoning and impairment in 2 of 4 domains of function (fine-motor skills, math calculation, visual executive functioning, and social skills). Sample weighting procedures adjusted for demographic differences in sample frequencies compared with underlying target populations. Inflation factor weights accounted for overrepresentation of psychiatric disorders (HBN and NKI samples).

RESULTS

Across 3 independent samples, the prevalence of NVLD was estimated among 2596 children and adolescents aged 6 to 19 years (mean [SD] age, 12.5 [3.4] years; 1449 male [55.8%]). After sample and inflation weights were applied, the prevalence of NVLD was 2.78% (95% CI, 2.03%-3.52%) in the HBN sample and 3.9% (95% CI, 1.96%-5.78%) in the NKI sample. In the SYS sample, the prevalence of NVLD was 3.10% (95% CI, 1.93%-4.27%) after applying the sample weight. Across samples and estimation strategies, the population prevalence of NVLD was estimated to range from 3% to 4%. When applied to the US population younger than 18 years, 2.2 million to 2.9 million children and adolescents were estimated to have NVLD.

CONCLUSIONS AND RELEVANCE

The findings suggest that the prevalence of NVLD in children and adolescents may be 3% to 4%. Given that few youths are diagnosed with NVLD and receive treatment, increased awareness, identification of the underlying neurobiological mechanisms, and development and testing interventions for the disorder are needed.

Nonverbal learning disability (developmental visuospatial disorder)

Nonverbal learning disability is a neurodevelopmental disorder with a core deficit in visuospatial processing with possibly associated problems in attention, motor, academic, and social skills, but without associated neurologic or genetic syndromes. The present chapter, after a brief historic overview of this disorder, will present fresh evidence that clearly shows neuropsychologic and neuroanatomical distinctions between children with nonverbal learning disability and those with other neurodevelopmental disorders. It ends with an attempt to find shared and valid diagnostic criteria. Acknowledging this disorder as a distinct diagnostic category will open up new research avenues with important scientific and clinical implications.

Impact of IQ on the diagnostic yield of chromosomal microarray in a community sample of adults with schizophrenia

Background

Schizophrenia is a severe psychiatric disorder associated with IQ deficits. Rare copy number variations (CNVs) have been established to play an important role in the etiology of schizophrenia. Several of the large rare CNVs associated with schizophrenia have been shown to negatively affect IQ in population-based controls where no major neuropsychiatric disorder is reported. The aim of this study was to examine the diagnostic yield of microarray testing and the functional impact of genome-wide rare CNVs in a community ascertained cohort of adults with schizophrenia and low (< 85) or average (≥ 85) IQ.

Methods

We recruited 546 adults of European ancestry with schizophrenia from six community psychiatric clinics in Canada. Each individual was assigned to the low or average IQ group based on standardized tests and/or educational attainment. We used rigorous methods to detect genome-wide rare CNVs from high-resolution microarray data. We compared the burden of rare CNVs classified as pathogenic or as a variant of unknown significance (VUS) between each of the IQ groups and the genome-wide burden and functional impact of rare CNVs after excluding individuals with a pathogenic CNV.

Results

There were 39/546 (7.1%; 95% confidence interval [CI] = 5.2–9.7%) schizophrenia participants with at least one pathogenic CNV detected, significantly more of whom were from the low IQ group (odds ratio [OR] = 5.01 [2.28–11.03], p = 0.0001). Secondary analyses revealed that individuals with schizophrenia and average IQ had the lowest yield of pathogenic CNVs (n = 9/325; 2.8%), followed by those with borderline intellectual functioning (n = 9/130; 6.9%), non-verbal learning disability (n = 6/29; 20.7%), and co-morbid intellectual disability (n = 15/62; 24.2%). There was no significant difference in the burden of rare CNVs classified as a VUS between any of the IQ subgroups. There was a significantly (p=0.002) increased burden of rare genic duplications in individuals with schizophrenia and low IQ that persisted after excluding individuals with a pathogenic CNV.

Conclusions

Using high-resolution microarrays we were able to demonstrate for the first time that the burden of pathogenic CNVs in schizophrenia differs significantly between IQ subgroups. The results of this study have implications for clinical practice and may help inform future rare variant studies of schizophrenia using next-generation sequencing technologies.

Electronic supplementary material

The online version of this article (doi:10.1186/s13073-017-0488-z) contains supplementary material, which is available to authorized users.

Prevalence of inter-hemispheric asymetry in children and adolescents with interdisciplinary diagnosis of non-verbal learning disorder

OBJECTIVE

To describe clinical and epidemiological features of children and adolescents with interdisciplinary diagnosis of non-verbal learning disorder and to investigate the prevalence of inter-hemispheric asymmetry in this population group.

METHODS

Cross-sectional study including children and adolescents referred for interdisciplinary assessment with learning difficulty complaints, who were given an interdisciplinary diagnosis of non-verbal learning disorder. The following variables were included in the analysis: sex-related prevalence, educational system, initial presumptive diagnoses and respective prevalence, overall non-verbal learning disorder prevalence, prevalence according to school year, age range at the time of assessment, major family complaints, presence of inter-hemispheric asymmetry, arithmetic deficits, visuoconstruction impairments and major signs and symptoms of non-verbal learning disorder.

RESULTS

Out of 810 medical records analyzed, 14 were from individuals who met the diagnostic criteria for non-verbal learning disorder, including the presence of inter-hemispheric asymmetry. Of these 14 patients, 8 were male.

CONCLUSION

The high prevalence of inter-hemispheric asymmetry suggests this parameter can be used to predict or support the diagnosis of non-verbal learning disorder.

OBJETIVO

Descrever as características clínicas e epidemiológicas de crianças e adolescentes com transtorno de aprendizagem não verbal, e investigar a prevalência de assimetria inter-hemisférica neste grupo populacional.

MÉTODOS

Estudo transversal que incluiu crianças e adolescentes encaminhados para uma avaliação interdisciplinar, com queixas de dificuldades de aprendizagem e que receberam diagnóstico interdisciplinar de transtorno de aprendizagem não verbal. As variáveis avaliadas foram prevalência por sexo, sistema de ensino, hipóteses diagnósticas iniciais e respectivas prevalências, prevalência de condições em relação à amostra total, prevalência geral do transtorno de aprendizagem não verbal, prevalência de acordo com ano escolar, faixa etária no momento da avaliação, principais queixas familiares, presença assimetria inter-hemisférica, dificuldade em aritmética, alterações em visuoconstrução, e principais sinais e sintomas do transtorno de aprendizagem não verbal.

RESULTADOS

Dos 810 prontuários médicos analisados, 14 eram de indivíduos que preencheram os critérios diagnósticos para transtorno de aprendizagem não verbal, incluindo a assimetria inter-hemisférica. Destes 14 pacientes, 8 eram do sexo masculino.

CONCLUSÃO

A alta prevalência de assimetria inter-hemisférica sugere que este parâmetro possa ser usado como preditor ou reforçador para diagnóstico de transtorno de aprendizagem não verbal.

Psychosocial Dimensions of Learning Disability Subtypes

Evidence bearing upon the relationships between profiles of neuropsychological assets and deficits, subtypes of learning disabilities, and patterns and degrees of psychosocial functioning is reviewed. The dimensions of incidence and type of psychosocial disturbance and the differential manifestations of these in two subtypes of learning disabilities are examined. Conclusions relating to the neurodevelopmental bases of the pattern of psychosocial functioning most often seen in children and adolescents with the syndrome of nonverbal learning disabilities are emphasized.

Simultaneous and Successive Cognitive Processing in Children with Nonverbal Learning Disabilities

This study compared the performance of 19 children with nonverbal learning disabilities to a comparison group of 16 children with language learning disabilities on measures of simultaneous and successive/sequential processing on the Kaufman Assessment Battery for Children (K-ABC). (The terms 'sequential' and 'successive' are used by different authors, so are applied interchangeably here). As hypothesized, children with nonverbal learning disabilities were found to have significantly higher Successive than Simultaneous Processing scores on the K-ABC, while children with language learning disabilities were found to have an inverse pattern of significantly higher Simultaneous than Successive Processing scores. The results suggest that different subtypes of learning disabilities can be defined through differences in cognitive processing. Further, the simultaneous-sequential/successive processing model may offer a valuable basis for conceptualizing learning disabilities in general, and nonverbal learning disabilities in particular. These findings have implications for the assessment and remediation of such learning disabilities.

The Association Between Motor Skills and Academic Achievement Among Pediatric Survivors of Acute Lymphoblastic Leukemia

OBJECTIVE

Assess the association between fine motor (FM) and visual-motor integration (VMI) skills and academic achievement in pediatric acute lymphoblastic leukemia (ALL) survivors.

METHODS

In this 28-site cross-sectional study of 256 children in first remission, a mean of 8.9 ± 2.2 years after treatment for standard-risk precursor-B ALL, validated measures of FM, VMI, reading, math, and intelligence were administered at mean follow-up age of 12.8 ± 2.5 years. 

RESULTS

 VMI was significantly associated with written math calculation ability (p < .0069) after adjusting for intelligence (p < .0001). VMI was more strongly associated with math in those with lower intelligence (p = .0141). Word decoding was also significantly associated with VMI but with no effect modification by intelligence. FM skills were not associated with either reading or math achievement.

CONCLUSION

These findings suggest that VMI is associated with aspects of math and reading achievement in leukemia survivors. These skills may be amenable to intervention.

The Interpretation of Emotion from Facial Expression for Children with Visual Processing Problems

A significant proportion of people with learning difficulties have social problems, which are often considered to be the product of school failure. However, a number of studies have suggested that these social skill problems may relate to the inability to decode subtle visual cues of body language and facial expression. The majority of studies of facial expression, however, have viewed learning disability as a unitary condition, without taking account of specific sub‐types which may have more difficulty in processing visual cues, especially for facial emotion. This study investigated children aged 8 to 12 years who were divided into three learning disability sub‐groups: 1) a visual‐perceptual sub‐type called Irlen Syndrome (n=41); 2) a group with learning disabilities, but no indications of Irlen Syndrome (n=30); and 3) a normally achieving control group (n=31). The Irlen Syndrome sub‐group had significantly lower scores for interpreting emotion from facial expression than the two other groups. The learning disabled non‐lrlen sub‐group also had significantly lower scores than the control group, but with much smaller levels of significance than those between the Irlen and control groups.

Grooved Pegboard for adult employed South Africans: normative data and human immunodeficiency virus associations

The Grooved Pegboard is a widely used test of psychomotor speed, and currently is used in particular to assess HIV-associated neurocognitive decline. To accurately interpret any assessment, appropriate reference norms are required. Although South Africa has the highest number of people living with HIV and AIDS, no local large scale reference data are available for the Grooved Pegboard. The main objective of the study was to formulate reference data for healthy adult South Africans in formal employment; two secondary objectives aimed to statistically explore the available Grooved Pegboard performance data, as well as its association with HIV status. Data were collected as part of multi-disciplinary occupational health screening, and included healthy HIV− adults ( N = 3118), and 70 HIV+ participants. This article presents normative reference data stratified across age and gender categories. The South African scores differ from other reported samples, emphasising the need to develop local norms that are context based, to facilitate clinical interpretation of psychomotor performance. Furthermore, in this sample, the Grooved Pegboard differentiated significantly between asymptomatic HIV+ persons, and those with HIV-associated neurocognitive disorders, although with poor predictive ability. In conclusion, large-sample reference data for healthy employed adult South Africans (age 19–59) are reported across gender and age categories, and may assist in more accurate screening of psychomotor speed generally, and HIV-associated neurocognitive decline in particular.

Social (pragmatic) communication disorder: a research review of this new DSM-5 diagnostic category

Social (pragmatic) communication disorder (SCD) is a new diagnostic category in the Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5). The purpose of this review is to describe and synthesize the relevant literature from language and autism spectrum disorder (ASD) research relating to pragmatic language impairment and other previously used terms that relate to SCD. The long-standing debate regarding how social communication/pragmatic impairments overlap and/or differ from language impairments, ASD, and other neurodevelopmental disorders is examined. The possible impact of the addition of SCD diagnostic category and directions for future research are also discussed.

Do older adults use the method of loci? Results from the ACTIVE study

BACKGROUND/STUDY CONTEXT: The method of loci (MoL) is a complex visuospatial mnemonic strategy. Previous research suggests that older adults could potentially benefit from using the MoL, but that it is too attentionally demanding for them to use in practice. The authors evaluated the hypotheses that training can increase the use of MoL, and that MoL use is associated with better memory.

METHODS

The authors analyzed skip patterns on response forms for the Auditory Verbal Learning Test (AVLT) in the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE; N = 1401) trial using 5 years of longitudinal follow-up.

RESULTS

At baseline, 2% of participants skipped spaces. Fewer than 2% of control participants skipped spaces at any visit across 5 years, but 25% of memory-trained participants, taught the MoL, did so. Participants who skipped spaces used more serial clustering, a hallmark of the MoL (p < .001). Trained participants who skipped spaces showed greater memory improvement after training than memory-trained participants who did not skip spaces (Cohen's d = .84, p = .007), and did not differ in the subsequent rate of long-term memory decline through up to 5 years of follow-up.

CONCLUSION

Despite being attentionally demanding, this study suggests that after training, the MoL is used by up to 25% of older adults, and that its use is associated with immediate memory improvement that was sustained through the course of follow-up. Findings are consistent with the notion that older adults balance complexity with novelty in strategy selection, and that changes in strategies used following memory training result in observable qualitative and quantitative differences in memory performance.

Applicability of the nonverbal learning disability paradigm for children with 22q11.2 deletion syndrome

Chromosome 22qll.2 deletion syndrome (22qllDS) is the most common microdeletion in humans. Nonverbal learning disability (NLD) has been used to describe the strengths and deficits of children with 22q11DS, but the applicability of the label for this population has seldom been systematically evaluated. The goal of the current study was to address how well the NLD diagnosis characterizes children and adolescents with 22q11DS. A total of 74 children and adolescents with 22q11DS were given neurocognitive, socioemotional, and academic assessments to measure aspects of NLD. Of the cohort, 20% met at least 7 of 9 assessed criteria for NLD; 25% showed verbal skills exceeding their nonverbal skills as assessed by an IQ test; and 24% showed the good rote verbal capacity commonly associated with NLD. Hypothesizing that if the entire cohort did not show consistent NLD characteristics, the descriptor might be more accurate for a distinct subgroup, the authors used latent class analysis to divide participants into three subgroups. However, the lines along which the groups broke out were more related to general functioning level than to NLD criteria. All three groups showed a heightened risk for psychiatric illness, highlighting the importance of careful mental health monitoring for all children with 22qllDS.

Neurocognitive disorders in sentenced male offenders: implications for rehabilitation

BACKGROUND

Neurocognitive deficits are frequent among male offenders and tend to be associated with a more serious risk of anti-social activity, but they are not systematically allowed for in rehabilitation programmes.

AIM

The aim of this study was to evaluate neurocognitive performance in a sample of sentenced Finnish male prisoners and consider the implications for prison programme entry.

METHODS

Seventy-five sentenced male prisoners were examined using a neurocognitive test battery.

RESULTS

Depending on the neurocognitive domain, from 5% to 49% of the men demonstrated marked neurocognitive deficits in tests of motor dexterity, visuospatial/construction skills, verbal comprehension, verbal and visual memory and attention shift. Verbal IQ was more impaired than performance IQ. There was no association between most serious offence type and neurocognitive performance, but correlations between attention deficit indices and number of previous convictions suggested that recidivists may have an attention disorder profile. Cluster analysis identified two subgroups of offenders, separated by very poor or merely poor cognitive performance. Motor dexterity, visuo-construction and verbal memory deficits were not wholly explained by lower IQ measures.

CONCLUSIONS AND IMPLICATIONS FOR PRACTICE

Our sample was small, but the nature and extent of the neurocognitive deficits found suggest that wider use of neurocognitive assessments, which the men generally tolerated well, could help select those most likely to need offender programmes and that the effectiveness of these may be enhanced by some specific cognitive remediation before progressing to more complex social tasks.

Executive function in nephropathic cystinosis

OBJECTIVE

We studied executive function (EF) in children and adolescents with cystinosis.

BACKGROUND

Cystinosis is a genetic metabolic disorder in which the amino acid cystine accumulates in all organs of the body, including the brain. Previous research has shown that individuals with cystinosis have visuospatial deficits, but normal intelligence and intact verbal abilities. Better understanding of the behavioral phenotype associated with cystinosis could have important implications for treatment.

METHODS

Twenty-eight children with cystinosis and 24 control participants (age range 8 to 17 years) underwent selected Delis-Kaplan executive function system tests for neuropsychological assessment of EF, and the participants' parents completed the behavior rating inventory of executive function.

RESULTS

Participants with cystinosis performed significantly more poorly than controls on all Delis-Kaplan Executive Function System indices examined and on the behavior rating inventory of executive function metacognition index and global executive composite.

CONCLUSIONS

EF is an area of potential risk in cystinosis. Our data have implications not only for the function of affected children and adolescents in school and daily life, but also for disease management and treatment adherence. Our findings can aid in the design and implementation of interventions and lead to a greater understanding of brain-behavior relationships in cystinosis.

Nonverbal learning disability

Nonverbal learning disability (NLD) is described as a subtype of specific learning disability where the source of the disability is a difficulty in processing nonverbal information. The child with NLD presents with problems in visual, spatial, and tactile perception but with strengths in rote verbal skills. Traditionally, these children were recognized by their difficulties in arithmetic which presented a stark contrast with their strengths in spelling and decoding text. They also exhibited a split between their verbal IQ (VIQ) and performance IQ (PIQ) scores with the VIQ being significantly higher than PIQ. Over time, however, diagnostic criteria have evolved and the broadened definition of the NLD syndrome has led many to question the utility and uniqueness of the NLD diagnosis. In addition, shifting diagnostic standards have made research results difficult to replicate. In short, the research to date leaves many unanswered questions about (1) the definition of the NLD syndrome, (2) the pervasiveness of the academic, social and psychopathological difficulties, (3) the source of the NLD syndrome, and (4) the degree to which it overlaps with other conditions. This chapter outlines a brief history of the NLD syndrome, how it is currently conceptualized, and some of the current debate about the unanswered questions above.

Spatial short-term memory in children with nonverbal learning disabilities: impairment in encoding spatial configuration

The authors investigated whether impaired spatial short-term memory exhibited by children with nonverbal learning disabilities is due to a problem in the encoding process. Children with or without nonverbal learning disabilities performed a simple spatial test that required them to remember 3, 5, or 7 spatial items presented simultaneously in random positions (i.e., spatial configuration) and to decide if a target item was changed or all items including the target were in the same position. The results showed that, even when the spatial positions in the encoding and probe phases were similar, the mean proportion correct of children with nonverbal learning disabilities was 0.58 while that of children without nonverbal learning disabilities was 0.84. The authors argue with the results that children with nonverbal learning disabilities have difficulty encoding relational information between spatial items, and that this difficulty is responsible for their impaired spatial short-term memory.

A Model to Guide the Conceptualization, Assessment, and Diagnosis of Nonverbal Learning Disorder

Although many learning disability types are formally recognized in major classification systems such as DSM-IV-TR and ICD-10, Nonverbal Learning Disorder (NLD) is not despite over 40 years of literature addressing its theoretical and neuropsychological foundation, its major features, and the methods by which to assess and diagnose it. Currently, there is no general agreement regarding the defining features of NLD and their relationship to daily functioning. Presented here is a description of NLD in the context of a model aimed at providing a standard language and framework for describing health and health-related states: the International Classification of Functioning, Disability and Health (ICF). It is proposed that the ICF model can guide clinical thinking, professional practice—including assessment, diagnosis, and treatment—and research with respect to NLD, eventually leading to the inclusion of NLD in formal classification systems.

Memory processes in learning disability subtypes of children born preterm

The purpose of this study was to evaluate immediate auditory and visual memory processes in learning disability subtypes of 40 children born preterm. Three subgroups of children were examined: (a) primary language disability group (n = 13), (b) perceptual-motor disability group (n = 14), and (c) no learning disability diagnosis group without identified language or perceptual-motor learning disability (n = 13). Between-group comparisons indicate no significant differences in immediate auditory or visual memory performances between language and perceptual-motor learning disability groups. Within-group comparisons revealed that both learning disability groups performed significantly lower on a task of immediate memory when the mode of stimulus presentation and mode of response were visual.

Memory training and strategy use in older adults: results from the ACTIVE study

Little is known about the long-term effects of memory training in later life on strategy use. Data from the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) study (n = 1,401) were used to describe strategy use in a community-dwelling sample of older adults. Strategy clustering scores on verbal list learning tasks of episodic memory were used to test the impact of memory training on strategy use and study longitudinal associations between strategy clustering, memory performance, and everyday functioning. Results suggested that younger, female, white, healthier, and more educated participants show higher strategy clustering scores initially but no characteristics were consistently associated with different trajectories in strategy clustering across all strategy clustering measures together. Memory training had significant immediate effects on all measures of strategy use that were maintained through five years of follow-up. With respect to longitudinal mediation, pre-post training changes in most strategy clustering scores mediate changes in objective memory performance and everyday functioning, implying that strategies can be modified and are closely related to both memory ability and the ability to function independently. This study provides evidence that older adults can be trained to use cognitive strategies, the effects are durable, and strategies are associated with memory and everyday functioning.

Imaginative Representations of Two - and Three-Dimensional Matrices in Children with Nonverbal Learning Disabilities

Children with non-verbal learning disabilities (NLD) are characterized by high verbal and poor non-verbal intelligence, poor cognitive abilities, school difficulties, and—sometimes—depressive symptoms. NLD children lack visuospatial working memory, but it is not clear whether they encounter difficulties in mental imagery tasks. In the present study, NLD adolescents without depressive symptoms, depressed adolescents without NLD symptoms, and a control group were administered a mental imagery task requiring them to imagine to move along the cells of a 2-D (5 × 5) or 3-D (3 × 3 × 3) matrix. Results showed that NLD adolescents had difficulty at performing the imagery task when a 3-D pattern was involved. It is suggested that 3-D mental imagery tasks tap visuospatial processes which are weak in NLD individuals. In addition, their poor cognitive performance cannot be attributed to a depressive state, as the depressed group had a performance similar to that of controls.

Nonverbal learning disabilities: a critical review

This article presents a critical review of the term and concept of nonverbal learning disability (NLD). After a brief historical introduction, the article focuses on the apparent rarity of NLD; the hypothesis of the frequent co-occurrence of emotional disorder, depression, and suicide in NLD; the white matter hypothesis as an explanation of the origin of NLD; and the question of NLD as part of a variety of other disorders. It is argued that NLD presents a broad hypothesis, but that there is little evidence to support its use in clinical practice.

Presence of cysts on magnetic resonance images (MRIs) in children with asperger disorder and nonverbal learning disabilities

The main purpose of this study was to report the existence of previously unidentified brain cysts or lesions in children with nonverbal learning disabilities, Asperger syndrome, or controls. The authors compared the incidence of cysts or lesions on magnetic resonance images (MRIs) in 28 children with nonverbal learning disability, 26 children with Asperger syndrome, and 24 typical controls for abnormalities. In this study, the authors found 25% of children previously diagnosed with nonverbal learning disability to have unsuspected brain abnormalities generally including cysts or lesions in the occipital region, compared with approximately 4% in the Asperger syndrome or control group. The cysts/lesions were found mainly in the occipital lobe, an area responsible for visual/spatial reasoning. It is appropriate to speculate that there might be a connection between anomalous brain development and skill differences among these groups.

Social cognition and its relation to psychosocial adjustment in children with nonverbal learning disabilities

The current study examined social cognitive skills in children with nonverbal learning disabilities (NLD) compared to normally achieving (NA) children. The relation between social cognitive skills and psychosocial adjustment was also investigated. There were no group differences on children's ability to represent orally presented social vignettes. Children with NLD were less able to recognize self-generated competent/assertive responses as the best solutions to a problem, expected fewer positive and more negative outcomes for examiner-provided competent responses, and showed a trend toward more frequently judging a story character as being mean. A social problem solving factor predicted unique variance in psychosocial adjustment beyond variance accounted for by nonverbal intelligence and nonverbal social cue interpretation. Results are discussed within a framework for which social cognitive deficits more broadly defined than encoding and interpreting nonverbal social cues contribute to the psychosocial adjustment problems of children with NLD.

The relation of humor and child development: social, adaptive, and emotional aspects

A sense of humor has been linked to social competence, popularity, and adaptability. The purpose of this review was to investigate the extant research in humor in childhood. Emerging work on the neuroanatomy of humor was discussed with findings of right hemispheric involvement for the comprehension and appreciation of humor for the affective network and the left hemisphere for cognitive understanding. These findings are intriguing when examining humor functioning in children with various disabilities, particularly the right hemisphere for children with autistic spectrum disorders or nonverbal learning disabilities. Examination of research in humor in childhood disabilities found most articles on humor in children with autistic spectrum disorder or mental retardation, with few to none in learning disabilities or attention deficit hyperactivity disorder. It was concluded that further study is needed to understand humor in children with disabilities and that such understanding will assist with interventions.

Recognition, expression, and understanding facial expressions of emotion in adolescents with nonverbal and general learning disabilities

Children with nonverbal learning disabilities (NVLD) have been found to be worse at recognizing facial expressions than children with verbal learning disabilities (LD) and without LD. However, little research has been done with adolescents. In addition, expressing and understanding facial expressions is yet to be studied among adolescents with LD subtypes. This study examined abilities of adolescents with NVLD, with general learning disabilities (GLD), and without LD to recognize, express, and understand facial expressions of emotion. Adolescents were grouped into those with NVLD, with GLD, and without LD using the Wechsler Intelligence Scale for Children-Third Edition (short form) and Wide Range Achievement Test-Third Edition. The adolescents completed neuropsychological, recognition, expression, and understanding measures. It is intriguing that the GLD group was significantly less accurate at recognizing and understanding facial expressions compared with the NVLD and NLD groups, who did not differ. Implications are explored with regard to the need to consider possible deficits in recognition and understanding of emotion in adolescents with LD in schools.

Mathematical learning disabilities in special populations: phenotypic variation and cross-disorder comparisons

What is mathematical learning disability (MLD)? The reviews in this special issue adopt different approaches to defining the construct of MLD. Collectively, they demonstrate the current status of efforts to establish a consensus definition and the challenges faced in this endeavor. In this commentary, we reflect upon the proposed pathways to mathematical learning difficulties and disabilities presented across the reviews. Specifically we consider how each of the reviews contributes to identifying the MLD phenotype by specifying the range of assets and deficits in mathematics, identifying sources of individual variation, and characterizing the natural progression of MLD over the life course. We show how principled comparisons across disorders address issues about the cognitive and behavioral co-morbidities of MLD, and whether commonalities in brain dysmorphology are associated with common mathematics performance profiles. We project the status of MLD research ten years hence with respect to theoretical gains, advances in methodology, and principled intervention studies.

Analogical problem solving in children with verbal and nonverbal learning disabilities

Analogical reasoning--perceiving similarities in different situations and the transfer of such information--facilitates learning and understanding. However, children with learning disabilities (LD) typically demonstrate deficits in such information processing strategies. In this study, we investigated the analogical problem-solving differences between children with verbal learning disabilities (VLD), nonverbal learning disabilities (NLD), or non-LD. Results indicated better recall of component stories by children without disabilities but no significant differences between the NLD and VLD participants. However, the success rate for target problem solving was much lower for the NLD group than for the VLD and non-LD groups. The poor performance of the NLD children may be attributed to some of their characteristic weaknesses, critical for analogical problem solving. Yet the VLD group was significantly weaker in recall than the non-LD group, but this did not hamper their analogical problem-solving abilities. These findings confirm that analogical thinking requires more than memory.

Comprehension of humor in children with nonverbal learning disabilities, reading disabilities, and without learning disabilities

The normal development of humor in children has been well documented with a predictable course that is tied to social, cognitive, and linguistic development in children. This study explored humor comprehension in children with nonverbal learning disabilities (NVLD). Children with NVLD were compared with children with reading disabilities and a comparison group of children with no learning disabilities to assess their comprehension of humor. The humor test was composed of a joke and cartoon section. No group differences in humor comprehension were found when the NVLD group was defined as having visual-spatial and visual reasoning deficits. However, when the NVLD group was divided into children with and without social perceptual difficulties as defined by a direct measure of social comprehension, significant group differences were found in the levels of humor comprehension. These results support the association of humor comprehension with social perception and lend tentative support to the hypothesis that children with NVLD may not be a homogenous group. Future study directions include further exploration into the nature of the association between humor comprehension and social perception as well as closer examination of the heterogeneity of NVLD.

Neuropsychological sequelae in patients with neurodegenerative Langerhans cell histiocytosis

BACKGROUND

Patients with Langerhans cell histiocytosis (LCH) may develop neurodegeneration and significant CNS sequelae, affecting a significant proportion of the patients. We here aimed to investigate the neuropsychological consequences in more detail.

METHODS

Using an extensive neuropsychological test battery, we evaluated nine LCH patients, 6-20 years old, with radiological signs indicative of neurodegeneration.

RESULTS

Altogether 3/9 patients performed below 1 SD of normal for age on full IQ. Detailed analysis revealed that 4/9 had deficient performance IQ, whereas 1/9 had subnormal verbal IQ (defined as below 1 SD). Furthermore, 3/8 patients showed slow speed of performance for age. Notably, 8/9 (89%) had deficient verbal working memory and 7/8 (88%) performed below normal on visual-spatial working memory.

CONCLUSIONS

The results indicate a specific, uneven neuropsychological profile in patients affected by CNS-LCH, with a decline particularly on perceptual tasks whereas the verbal performance was not as negatively influenced. Furthermore, verbal and visual-spatial working memory functions were below normal for age in all but one patient studied. LCH may easily be misdiagnosed, but it is important that individuals affected by CNS-LCH are diagnosed to provide advice and support. It remains a challenge to find a treatment reducing this unfortunate neurodegeneration.

Is there an increased familial prevalence of psychopathology in children with nonverbal learning disorders?

The cognitive and behavioral symptoms of nonverbal learning disabilities (NLD) have been described by previous investigators. Nevertheless, we know far less about the potential genetic contributions that may predispose a child to have NLD. An endophenotype model was investigated in 5 samples of children ages 9 to 15 years: NLD (n = 32); reading disorders (RD; n = 59); participants with a psychiatric diagnosis but without a learning disability (n = 55); typically developing controls (n = 31); and children with velocardiofacial syndrome (VCFS), a chromosomal deletion syndrome that has been proposed as being an exemplar of NLD (VCFS + NLD; n = 20). Based on a family genetic interview, the authors' data suggest that children with NLD, RD, or a psychiatric diagnosis have a higher prevalence rate of attention-deficit/hyperactivity disorder (ADHD) and substance abuse/dependence. Psychiatric controls and children with NLD--but not children with RD-- showed higher prevalence rates of familial bipolar disorder.

The influence of instruction modality on brain activation in teenagers with nonverbal learning disabilities: two case histories

Teenagers with nonverbal learning disabilities (NLD) have difficulty with fine-motor coordination, which may relate to the novelty of the task or the lack of "self-talk" to mediate action. In this study, we required two teenagers with NLD and two control group teenagers to touch the thumb of each hand firmly and accurately to the fingertips of the same hand, in an order specified by verbal or tactile instruction. Brain activity patterns (measured using functional magnetic resonance imaging) suggest that unlike control participants, the NLD participants used internalized speech to facilitate the novel task only when instructions were verbal. NLD participants also showed activity in a more widely distributed network of neural structures. These findings provide preliminary evidence for remediation strategies that encourage internal speech.

Taxonicity of nonverbal learning disabilities in spina bifida

As currently defined, it is not clear whether Nonverbal Learning Disabilities (NLD) should be considered a matter of kind or magnitude (Meehl, 1995). The taxonicity of NLD, or the degree to which it is best construed as discrete versus continuous, has not been investigated using methods devised for this purpose. Latent Class Analysis (LCA) is a method for finding subtypes of latent classes from multivariate categorical data. This study represents an application of LCA on a sample of children and adolescents with spina bifida myelomeningocele (SBM) (N = 44), those presenting with features of NLD (N = 28) but no medical condition, and control volunteers (N = 44). The two-class solution provided evidence for the presence of a taxon with an estimated base-rate in the SBM group of .57. Indicator validities (the conditional probabilities of indicator endorsement in each latent class) suggest a somewhat different priority for defining NLD than is typically used by researchers investigating this disorder. A high degree of correspondence between LCA classifications and those based on a more conventional algorithm provided evidence for the validity of this approach.

Auditory Processing Disorder in Children Diagnosed With Nonverbal Learning Disability

Purpose

To determine whether children with a nonverbal learning disability (NVLD) have a higher incidence of auditory processing disorder (APD), especially in the tolerance-fading memory type of APD, and what associations could be found between performance on neuropsychological, intellectual, memory, and academic measures and APD.

Method

Eighteen children with NVLD ranging in age from 6 to 18 years received a central auditory processing test battery to determine incidence and subtype of APD. Psychological measures for assessment of NVLD included the Wechsler Scales, Wide Range Assessment of Memory and Learning, and Wechsler Individual Achievement Test. Neuropsychological measures included the Category Test, Trails A and B, the Tactual Performance Test, Grooved Pegs, and the Speech Sounds Perception Test. Neuropsychological test scores of the NVLD+APD and NVLD groups were compared using analysis of covariance procedures, with Verbal IQ and Performance IQ as covariates.

Results

Sixty-one percent of the children were diagnosed with APD, primarily in the tolerance-fading memory subtype. The group of children with APD and NVLD had significantly lower scores on Verbal IQ, Digit Span, Sentence Memory, Block Design, and Speech Sounds Perception than children without APD. An ancillary finding was that the incidence of attention deficit/hyperactivity disorder was significantly higher in children with NVLD (with and without APD) than in the general population.

Conclusion

The results indicate that children with NVLD are at risk for APD and that there are several indicators on neuropsychological assessment suggestive of APD. Collaborative, interdisciplinary evaluation of children with learning disorders is needed in order to provide effective therapeutic interventions.

Case Illustration of a Boy With Nonverbal Learning Disorder and Asperger's Features: Neuropsychological and Personality Assessment

I present a case study of a latency-age boy referred for assessment of a nonverbal learning disability/disorder (NLD) who also had features of Asperger's syndrome (AS). I review NLD terminology, presumed brain-behavior relationship, neuropsychological profile, and diagnosis/classification issues. I discuss the challenge of differentiating NLD from AS in relation to the client's pattern of visual-spatial, communication, social-emotional, and behavioral NLD correlates. I integrate neuropsychological and personality assessment data with interviews, observations, prior testing, and input from teacher and therapist in formulating a diagnostic impression. I discuss Rorschach (Exner, 2003) and neuropsychological consultations in relation to subtle language and interpersonal features of the client's communication style. I provide parent feedback at 18 and 24 months posttesting. I discuss implications relative to a model of school neuropsychological assessment that includes the Rorschach test.