Verbal Memory Deficits in Children with Less than 750 g Birth Weight

Numerous studies have documented memory deficits in very low birthweight (VLBW, < 1500 g) children, yet we know little about the nature of these memory problems. To clarify memory sequelae and examine memory deficits in relation to the degree of low birth weight, we administered the California Verbal Learning Test–Children’s Version (CVLT-C) to a regional sample of 57 < 750 g birthweight children and to groups of 53 750–1499 g birthweight children and 49 term-born controls. Group comparisons revealed significant differences between the < 750 g birthweight group and term-born children on measures of list learning, delayed recall, and inaccurate recall. In addition, the percentage improvement in correct recognitions relative to long-term delayed recall was greater in the < 750 g group than in the term-born controls. Similar differences were observed between VLBW children with and without abnormal neonatal cerebral ultrasounds (high- and low-risk groups). Differences in learning rate between the VLBW and term-born groups, and between high- and low-risk VLBW children, were evident even when vocabulary skill was covaried or when children with neurosensory deficits or IQ < 80 were excluded from analysis. The findings document deficits in verbal memory in the subset of VLBW children at greatest biological risk, and suggest that acquisition processes are selectively impaired.     

Selective and sustained attention in children with spina bifida myelomeningocele

This study examined memory functioning in children and adolescents with 22q11.2 Deletion Syndrome (DS; velocardiofacial syndrome). An overall verbal better than nonverbal memory pattern was evident on the Test of Memory and Learning (TOMAL), with children with 22q11.2 DS performing significantly below their siblings and children with low average IQ but similar to children with autism on facial memory. Children with 22q11 DS also performed significantly below their siblings on tests of verbal working memory. Children with autism performed significantly poorer than the siblings of children with 22q11.2 DS only on their recall of stories. Delayed recall was significantly poorer in children with 22q11.2 DS and children with autism, compared to sibling controls. Although there were no significant group differences on tests of multiple trial verbal or visual learning, a relative weakness was noted with multiple trial visual learning in children with 22q11.2 DS and their siblings, suggesting that an alternative or interactive factor other than the deletion may account for the relatively better verbal compared to nonverbal memory abilities. Deficits in facial memory in children with both 22q11.2 DS and autism suggest disruptions in ventral temporal pathways such as between fusiform gyrus and parahippocampal/hippocampal regions whereas deficits in verbal working memory in children with 22q11.2 DS implicates dorsolateral prefrontal regions, both intimating aberrant white matter pathways.     

22q11.2 Deletion Syndrome: Genetics,Neuroanatomy and Cognitive/Behavioral Features Keywords

This paper presents a conceptual review of the genetic underpinnings of 22q11.2 Deletion Syndrome. The neuroanatomical, neuropsychological, behavioral, and psychiatric phenotype associated with 22q11.2 Deletion Syndrome is also explored, including variables that are thought to affect symptom expression. The history of the deletion syndrome is described, and future directions for continued research are discussed.     

Atypical Neuropsychological Profile in a Boy with 22q11.2 Deletion Syndrome Keywords:

In this article the general and specific cognitive impairments of the boy R.H. with a de novo deletion 22q11.2 are described. His full-scale IQ was 73, and he obtained only slightly better verbal than non-verbal subtest scores. Neuropsychological assessment revealed specific impairments in perceptual categorization of objects presented suboptimal, matching of unfamiliar faces, and verbal learning and memory. In contrast, he performed in accordance with his intelligence level on other visual perceptual tasks, on non-verbal learning and memory tasks, and on attention tasks. Voxel-wise statistical comparison of a high-resolution T1-weighted magnetic resonance image of R.H’s brain with similar images obtained from 14 normal control children revealed as major abnormalities a reduction of the right inferior parietal and superior occipital lobe, and a bilateral reduction of deep white matter behind the inferior frontal gyrus. These cognitive impairments and MRI abnormalities are not commonly described in 22q11.2 Deletion Syndrome and may indicate a larger heterogeneity in the neurocognitive phenotype than currently evidenced. At least in this boy the microdeletion seems to have interfered with the development and functioning of particular neural subsystems, while the structure and functioning of other subsystems was left intact.     

Gender-Moderated Dorsolateral Prefrontal Reductions in 22q11.2 Deletion Syndrome: Implications for Risk for Schizophrenia

To investigate the impact of the microdeletion on morphology of the prefrontal cortex in 22q11.2 Deletion Syndrome (22q11.2 DS), high-resolution, anatomic magnetic resonance imaging was performed on 19 children and adolescents with 22q11.2 DS (11 females, 8 males) and 18 unaffected controls (10 females, 8 males). Tissue volumes of the dorsolateral, dorsomedial, orbitolateral, and orbitomedial prefrontal cortex were measured. Tasks of executive function and working memory were administered to investigate the association between anatomy and function. Whole brain volume and frontal lobe tissue volume were preserved in girls but reduced in boys with 22q11.2 DS relative to age-matched controls. Dorsolateral prefrontal cortex (DLPFC) volumes were reduced in participants with 22q11.2 DS, although the gender-by-diagnosis effect found for frontal lobe was not as robust for DLPFC. DLPFC volumes were associated with performance on tasks of planning and emotional facial recognition. Longitudinal studies are needed to clarify whether gender differences in frontal lobe and DLPFC persist with development, and whether the volumes of the DLPFC are associated with eventual deterioration in adaptive/psychosocial function that may presage the onset of schizophrenia, for which individuals with 22q11.2 DS are at a disproportionately high risk.     

Evidence of Poor Planning in Children with Attention Deficits

This study examined the planning performance of children with attention deficits, and also investigated the possible interactions between inattention and anxiety in the performance of executive function tasks. A group of 98 children (grades 4 and 6), derived from an initial group of 550, were assigned to an attention difficulties group (AD) and a control group (n = 49 each) based on their scores on a variety of cognitive attention measures and teacher scales of attention and hyperactivity. The two groups were matched on age, gender, parental education, non-verbal and verbal ability. They were compared on Crack-the-Code (C-t-C) action-planning task, embedded and ambiguous figures and Theory of Mind tasks. Analyses indicated that the failure of AD children on cognitive performance measures is linked to planning impairments. The co-occurrence of anxiety, in turn, did not interact with inattention to affect planning performance differentially. Implications of these findings for the current discussion about the cognitive and emotional processes underlying impaired performance among children with attention deficits on executive control tasks are discussed.     

Domain specific attentional impairments in children with chromosome 22q11.2 deletion syndrome

One of the defining cognitive characteristics of the chromosome 22q deletion syndrome (DS22q11.2) is visuospatial processing impairments. The purpose of this study was to investigate and extend the specific attentional profile of children with this disorder using both an object-based attention task and an inhibition of return task. A group of children with the disorder was compared in these tasks with a group of age-matched typically developing children. The children with DS22q11.2 demonstrated impaired spatially based orienting which is consistent with previous findings in this group. Strikingly, the children with DS22q11.2 also demonstrated an improved ability to use object-based cues, relative to the typically developing group. Finally, the children with DS22q11.2 demonstrated an intact inhibition of return system, however, it appears to be delayed developmentally.     

The Motor Profile of Primary School-Age Children with a 22q11.2 Deletion Syndrome (22q11.2DS) and an Age- and IQ-Matched Control Group

In the early publications on the 22q11.2 Deletion Syndrome (22q11.2DS) motor abnormalities have been frequently reported. However, systematic studies on the motor performance of children with the 22q11.2DS, and especially of school-age children, are scarce. In this study the motor performance of primary school-age children with a 22q11.2DS (n = 28) was compared with an age- and IQ-matched control group (n = 28) using the Movement Assessment Battery for Children (MABC), the Körperkoordinationstest für Kinder (KTK) and the Beery-Buctenica test of Visual-Motor Integration (Beery). Children with a 22q11.2DS scored significantly lower than the age- and IQ-matched control group on the subsection Manual Dexterity (MABC) and the Visual Perception and Motor Coordination subtests of the Beery. When investigating the correlations between Intelligence quotient (IQ) and motor performance, a specific profile was found in the 22q11.2DS group when compared with the age- and IQ-matched control group. Because an IQ-matched control group was adopted, the deficits in visual-perceptual and visuomotor integration skills cannot fully be attributed to a general developmental delay and thus may be specific for the 22q11.2DS. Future studies that investigate the specificity of the visual-perceptual problems — both on the behavioral and brain level (functional Magnetic Resonance Imaging [fMRI] and Diffusion Tensor Imaging [DTI]) — are necessary to answer this question. Nonetheless, the importance of incorporating motor functioning into the study of the neuropsychological profile of children with a 22q11.2DS has to be stressed.     

Social and non‐social measures of cognition for predicting self‐reported and informant‐reported functional outcomes in early psychosis

The main aim of this study was to investigate the individual contributions of neurocognitive and social‐cognitive domains to self‐reported and informant‐reported functional outcome in early psychosis. We also sought to further characterize the nature of cognitive impairments in this sample and explore the interrelationships between the social‐cognitive measures and how they correlate with measures of neurocognition and clinical symptoms. In this study, 70 patients (mean age: 24.1; 87.1% males) with primary psychotic disorder diagnosed in the previous 5 years were assessed on multiple neurocognitive (processing speed, attention, working memory, immediate verbal memory, delayed recall, visual reasoning, inhibition, planning, cognitive flexibility), and social‐cognitive domains (theory of mind (ToM), emotion recognition, attributional style, metacognitive overconfidence) as well as measures of clinical symptoms. Functional outcome was assessed with three self‐reports and two informant‐reports. On average, patients performed one or more SD below healthy controls on measures of delayed recall, ToM and metacognitive overconfidence. Emotion recognition and ToM were intercorrelated and correlated with multiple neurocognitive domains and negative symptoms. Attributional style correlated with positive symptoms. In the context of multiple variables, self‐reported functional outcomes were predicted by attributional style, whereas emotion recognition and immediate verbal memory predicted variance in informant‐reported community functioning. These results support the suggestion of a likely distinction between the predictive factors for self‐reported and informant‐reported functional outcome in early psychosis and suggest that consideration of self‐assessment of functional outcome is critical when attempting to evaluate the effects attributional style has on functional disability.     

Social cognition and real-life functioning in patient samples with 22q11.2 deletion syndrome with or without psychosis,compared to a large sample of patients with schizophrenia only and healthy controls

Patients with the 22q11.2 deletion syndrome (DS) show an increased risk of developing a psychotic illness lifetime. 22q11.2DS may represent a reliable model for studying the neurobiological underpinnings of schizophrenia. The study of social inference abilities in a genetic condition at high risk for psychosis, like 22q11.2DS, may shed light on the relationships between neurocognitive processes and patients' daily general functioning. The study sample consisted of 1736 participants, divided into four groups: 22q11.2DS patients with diagnosis of psychotic disorder (DEL SCZ, N = 20); 22q11.2DS subjects with no diagnosis of psychosis (DEL, N = 43); patients diagnosed with schizophrenia without 22q11.2DS (SCZ, N = 893); and healthy controls (HC, N = 780). Social cognition was assessed through The Awareness of Social Inference Test (TASIT) and general functioning through the Specific Levels of Functioning (SLoF) scale. We analysed data through regression analysis. The SCZ and DEL groups had similar levels of global functioning; they both had significantly lower SLoF Total scores than HC (p < .001); the DEL SCZ group showed significantly lower scores compared to the other groups (SCZ, p = .004; DEL, p = .003; HC, p < .001). A significant deficit in social cognition was observed in the three clinical groups. In the DEL SCZ and SCZ groups, TASIT scores significantly predicted global functioning (p < .05). Our findings of social cognition deficit in psychosis-prone patients point to the possible future adoption of rehabilitation programmes, like Social Skills Training and Cognitive Remediation, during premorbid stages of psychosis.