A Neuropsychological Profile for Agenesis of the Corpus Callosum? Cognitive, Academic, Executive, Social, and Behavioral Functioning in School-Age Children.

OBJECTIVES: Agenesis of the corpus callosum (AgCC), characterized by developmental absence of the corpus callosum, is one of the most common congenital brain malformations. To date, there are limited data on the neuropsychological consequences of AgCC and factors that modulate different outcomes, especially in children. This study aimed to describe general intellectual, academic, executive, social and behavioral functioning in a cohort of school-aged children presenting for clinical services to a hospital and diagnosed with AgCC. The influences of age, social risk and neurological factors were examined. METHODS: Twenty-eight school-aged children (8 to 17 years) diagnosed with AgCC completed tests of general intelligence (IQ) and academic functioning. Executive, social and behavioral functioning in daily life, and social risk, were estimated from parent and teacher rated questionnaires. MRI findings reviewed by a pediatric neurologist confirmed diagnosis and identified brain characteristics. Clinical details including the presence of epilepsy and diagnosed genetic condition were obtained from medical records. RESULTS: In our cohort, ~50% of children experienced general intellectual, academic, executive, social and/or behavioral difficulties and ~20% were functioning at a level comparable to typically developing children. Social risk was important for understanding variability in neuropsychological outcomes. Brain anomalies and complete AgCC were associated with lower mathematics performance and poorer executive functioning. CONCLUSIONS: This is the first comprehensive report of general intellectual, academic, executive social and behavioral consequences of AgCC in school-aged children. The findings have important clinical implications, suggesting that support to families and targeted intervention could promote positive neuropsychological functioning in children with AgCC who come to clinical attention. (JINS, 2018, 24, 445-455).

Interhemispheric cortical connections and time perception: A case study with agenesis of the corpus callosum.

In daily life, we sometimes select temporal cues of one sort while suppressing others. This study investigated the mechanism of suppression by examining a split-brain patient's perception of target intervals while ignoring distractor intervals. A patient with agenesis of corpus callosum and five age- and sex-matched control subjects participated in reproduction of target intervals while ignoring distractors displayed in the visual field either ipsilateral or contralateral to target. In the patient, the distractor interfered with reproduction performance more strongly when contralateral rather than ipsilateral. Our results suggest that the corpus callosum plays an inhibitory role in interhemispheric interference and that temporal interval information can be transferred via subcortical structures when there are no direct interhemispheric pathways.

[Behavioral and cognitive profile of corpus callosum agenesia - Review]. / A corpus callosum agenesia viselkedéses és kognitív profilja - összefoglaló.

BACKGROUND AND PURPOSE: Agenesis of corpus callosum is a relatively frequent congenital cerebral malformation including dysplasia, total or partial absence of corpus callosum. The agenesis of corpus callosum can be occured in isolated form without accompanying somatic or central nervous system abnormalities and it can be associated with other central nervus system malformations. The behavioral and cognitive outcome is more favorable for patients with isolated agenesis of corpus callous than syndromic form of corpus callosum. The aim of this study is to review recent research on behavioral and social-cognitive functions in individuals with agenesis of corpus callosum. Developmental delay is common especially in higher-order cognitive and social functions. METHODS: An internet database search was performed to identify publications on the subject. RESULTS: Fifty-five publications in English corresponded to the criteria. These studies reported deficits in language, social cognition and emotions in individuals with agenesis of corpus callosum which is known as primary corpus callous syndrome. CONCLUSION: The results indicate that individuals with agenesis of corpus callosum have deficiency in social-cognitive domain (recognition of emotions, weakness in paralinguistic aspects of language and mentalizing abilities). The impaired social cognition can be manifested in behavioral problems like autism and attention deficit hyperactivity disorder.

Case study: a patient with agenesis of the corpus callosum with minimal associated neuropsychological impairment.

This is a case study of an 88-year-old man who presented with agenesis of the corpus callosum and colpocephaly. Symptomatically, he reported a sudden onset of mild, intermittent left hand apraxia, but denied any previous manifestations consistent with this type of brain malformation. The patient underwent neuroimaging, evaluation by neurology, and comprehensive neuropsychological testing to determine the nature of any other associated impairments. Test results indicated that he was, with a few exceptions, neuropsychologically normal. He performed well on tests that are highly sensitive to acquired brain dysfunction. His most notable deficit was failed performance in the simultaneous and coordinated use of both hands in using tactile and proprioceptive feedback on the Tactual Performance Test. This case is discussed in terms of plasticity of the developing brain, including compensatory mechanisms, highlighting the variability in clinical outcome in the context of congenital brain malformation. This case study illustrates the strong influence of cerebral plasticity as well as a possible circumscribed manifestation of interhemispheric disconnection.

Neuropsychological functioning in dysgenesis of the corpus callosum with colpocephaly.

Dysgenesis of the corpus callosum is a rare developmental abnormality in brain structure that is associated with changes in physical appearance, as well as behavioral and cognitive consequences. A relatively commonly co-occurring structural abnormality with callosal dysgenesis is colpocephaly, characterized by enlargement of the posterior lateral ventricles and reductions in posterior brain volume. Although some case studies of individuals with this combination of structural malformations exist, they do not often report results of neuropsychological evaluation. Furthermore, those that do contain neuropsychological data may be of limited generalizability due to unique patient characteristics. The current manuscript overcomes these limitations by presenting the case of a 55-year-old male with callosal dysgenesis and colpocephaly identified in adulthood. The paper includes a full profile of his performance on a comprehensive neuropsychological test battery with discussion of differential diagnosis and treatment planning. Findings indicated low average intellectual abilities with deficits in processing speed, executive functions, and social cognition, consistent with expectations based on callosal dysgenesis. One surprising finding was that despite the significant posterior involvement of colpocephaly, visuospatial skills were a relative strength. The manuscript provides a clear characterization of callosal dysgenesis with colpocephaly to facilitate future clinical comparisons and set the stage for future research on this rare neuromorphological presentation.

[Cancer in children with intellectual disabilities: Questioning and ethical issues]. / Cancer chez un enfant porteur de handicap intellectuel : questionnement et enjeux éthiques.

The Parents and Caregivers group in the face of ethics in pediatrics of the Île-de-France Ethics Area wondered about the association of the words Disability and Cancer by focusing on the study of the course of children with intellectual disability, treated for cancer. These situations are exceptional, the number of cases in France must not be more than fifty per year. We gathered the testimony of five families of children using a semi-directive survey taking up the journey from birth, announcement of the handicap, the diagnosis of cancer and its treatment. The verbatim show that each story is unique and rich in lessons, despite the feeling of "double penalty": "He did not deserve this, a handicap plus cancer is a lot for one person", "the shot moreover." A healthcare team was also interviewed and raised an additional question: "First, the double penalty… then, what's the point?" Through these testimonies, we sought to question the ethical principles of care, which can be shaken up in these extraordinary supported.

Awareness of consequences in agenesis of the corpus callosum: Semantic analysis of responses.

OBJECTIVE: Agenesis of the corpus callosum (AgCC) in individuals with general intelligence within the normal range results in a syndrome of mild to moderate deficiencies in cognitive, emotional, and social functioning that are still being explored. Anecdotal accounts from families suggest that these cognitive and psychosocial deficiencies affect the ability of these individuals to anticipate the consequences of their decisions and behaviors. This research was designed to clarify the nature of social and emotional cognition in AgCC with respect to imagination of the consequences of decisions by assessing responses from the Awareness of Consequences Scale (AOCS). METHOD: Verbal AOCS responses from persons with AgCC and age and IQ-matched neurotypical controls were scored in the normal manner, and also subjected to semantic analyses using both latent semantic analysis and Linguistic Inquiry and Word Count. RESULTS: It was found that, relative to neurotypical controls, individuals with AgCC scored significantly lower on the typical scoring of the AOCS, had nontypical semantic content in their responses, and used fewer emotion and cognitive content (insight) words. These results were apparent in responses to the three most complex of the AOCS scenarios. CONCLUSIONS: Results were consistent with the hypothesis that persons with AgCC are deficient in the capacity to imagine the emotional and cognitive consequences of potential actions on others. particularly in the face of greater situational and social complexity. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Clinical Characterization, Genetics, and Long-Term Follow-up of a Large Cohort of Patients With Agenesis of the Corpus Callosum.

To gain a better understanding of the clinical and genetic features associated with agenesis of corpus callosum, we enrolled and characterized 162 patients with complete or partial agenesis of corpus callosum. Clinical and genetic protocols allowed us to categorize patients as syndromic subjects, affected by complex extra-brain malformations, and nonsyndromic subjects without any additional anomalies. We observed slight differences in sex ratio (56% males) and agenesis type (52% complete). Syndromic agenesis of corpus callosum subjects were prevalent (69%). We detected associated cerebral malformations in 48% of patients. Neuromotor impairment, cognitive and language disorders, and epilepsy were frequently present, regardless of the agenesis of corpus callosum subtype. Long-term follow-up allowed us to define additional indicators: syndromic agenesis of corpus callosum plus patients showed the most severe clinical features while isolated complete agenesis of corpus callosum patients had the mildest symptoms, although we observed intellectual disability (64%) and epilepsy (15%) in both categories. We achieved a definitive (clinical and/or genetic) diagnosis in 42% of subjects.

Sleep Problems in Children With Agenesis of the Corpus Callosum.

BACKGROUND: Very little is known about sleep habits in children with agenesis of the corpus callosum (ACC). The purpose of this investigation was to evaluate sleep problems in children with ACC and examine the association with quality of life. METHODS: We performed a cross-sectional, anonymous, internet-based survey offered to parents of children with ACC, aged five to 18 years. The Children's Sleep Habits Questionnaire (CSHQ) and pediatric quality of life (PedsQL) were used to assess sleep habits and quality of life, respectively. Associations between the total and all subdomains of CSHQ and PedsQL were tested. RESULTS: The final sample included 66 parents of children with ACC. Overall, 78% of the children had clinically significant sleep problems, using a cutoff score of 41 on the CSHQ. Compared with a prior national sample of typically developing children, children with ACC scored significantly higher overall and in all subdomains of the CSHQ. The overall CSHQ and PedsQL were moderately correlated (r = -0.485, P < 0.001), indicating that children with more sleep problems had worse quality of life. In addition, the total CSHQ correlated with all subdomains of the pediatric quality of life, including emotional (r = -0.515, P < 0.01), social (r = -0.394, P < 0.01), physical (r = -0.263, P < 0.01), and school (r = -0.362, P < 0.01). These associations remained statistically significant in multivariable regression models controlling for age and gender. CONCLUSIONS: Sleep problems are common and associated with lower quality of life in children with ACC.

Imaging of Congenital Malformations.

PURPOSE OF REVIEW: Intracranial congenital malformations are anomalies of brain development caused by genetic and environmental influences. This article discusses common intracranial congenital malformations, presents the associated neuroimaging findings, and discusses how appropriate identification of intracranial anomalies can impact diagnosis and treatment. RECENT FINDINGS: Advances in neuroimaging techniques and genetic research have led to a better understanding of the pathogenesis of many congenital malformations, adding insight into their clinical relevance and the intricate relationship between critical periods of development, genetic predisposition, and environmental insults. When one malformation is discovered, a high likelihood of more malformations exists. In some instances, the intracranial anomalies will lead to the diagnosis of a particular neurologic syndrome, which may, in turn, lead to modification of a plan of care. SUMMARY: Knowledge of congenital malformations and their appearance on imaging sequences is essential to improve clinical outcomes and quality of life for patients.

Individuals with agenesis of the corpus callosum show sensory processing differences as measured by the sensory profile.

OBJECTIVE: Given reports of high pain thresholds and reduced auditory response in individuals with agenesis of the corpus callosum (AgCC), this study investigated whether affected participants report atypical experiences and behaviors on a well-established sensory processing measure. METHODS: Fourteen participants with AgCC (ages 11-59) completed the Adolescent/Adult Sensory Profile (Brown & Dunn, 2001). Sensory profile scales were classified as "Atypical" if they were more than 1 standard deviation from the mean. RESULTS: Fifty-seven percent of participants with AgCC reported reduced sensory registration as compared to an expected 16% of the normative sample. Similarly, 50% of the AgCC participants reported atypically increased auditory processing difficulties. CONCLUSIONS: Using a well-established sensory processing questionnaire, participants with AgCC reported measurable differences in multiple aspects of sensory processing. The most notable difference was in the quadrant of low sensory registration, suggesting that individuals with AgCC may require sensory information to be presented more slowly or at a higher intensity for adequate processing. The sensory modality that was most affected was the auditory system, which is consistent with increased rates of language disorders and autism spectrum disorders in this population. Understanding sensory processing in individuals with AgCC can both elucidate the role of interhemispheric transfer in the development of intact sensory processing as well as contribute to our knowledge of the role of the corpus callosum in a range of disorders in which sensory processes are impacted. (PsycINFO Database Record

Verbal learning and memory in agenesis of the corpus callosum.

The role of interhemispheric interactions in the encoding, retention, and retrieval of verbal memory can be clarified by assessing individuals with complete or partial agenesis of the corpus callosum (AgCC), but who have normal intelligence. This study assessed verbal learning and memory in AgCC using the California Verbal Learning Test-Second Edition (CVLT-II). Twenty-six individuals with AgCC were compared to 24 matched controls on CVLT-II measures, as well as Donders׳ four CVLT-II factors (i.e., Attention Span, Learning Efficiency, Delayed Memory, and Inaccurate Memory). Individuals with AgCC performed significantly below healthy controls on the Delayed Memory factor, confirmed by significant deficits in short and long delayed free recall and cued recall. They also performed less well in original learning. Deficient performance by individuals with AgCC during learning trials, as well as deficits in all forms of delayed memory, suggest that the corpus callosum facilitates interhemispheric elaboration and encoding of verbal information.

Short-term and long-term memory deficits in handedness learning in mice with absent corpus callosum and reduced hippocampal commissure.

The corpus callosum (CC) and hippocampal commissure (HC) are major interhemispheric connections whose role in brain function and behaviors is fascinating and contentious. Paw preference of laboratory mice is a genetically regulated, adaptive behavior, continuously shaped by training and learning. We studied variation with training in paw-preference in mice of the 9XCA/WahBid ('9XCA') recombinant inbred strain, selected for complete absence of the CC and severely reduced HC. We measured sequences of paw choices in 9XCA mice in two training sessions in unbiased test chambers, separated by one-week. We compared them with sequences of paw choices in model non-learner mice that have random unbiased paw choices and with those of C57BL/6JBid ('C57BL/6J') mice that have normal interhemispheric connections and learn a paw preference. Positive autocorrelation between successive paw choices during each session and change in paw-preference bias between sessions indicate that 9XCA mice have weak, but not null, learning skills. We tested the effect of the forebrain commissural defect on paw-preference learning with the independent BTBR T+ tf/J ('BTBR') mouse strain that has a genetically identical, non-complementing commissural trait. BTBR has weak short-term and long-term memory skills, identical to 9XCA. The results provide strong evidence that CC and HC contribute in memory function and formation of paw-preference biases.

Autism traits in individuals with agenesis of the corpus callosum.

Autism spectrum disorders (ASD) have numerous etiologies, including structural brain malformations such as agenesis of the corpus callosum (AgCC). We sought to directly measure the occurrence of autism traits in a cohort of individuals with AgCC and to investigate the neural underpinnings of this association. We screened a large AgCC cohort (n = 106) with the Autism Spectrum Quotient (AQ) and found that 45 % of children, 35 % of adolescents, and 18 % of adults exceeded the predetermined autism-screening cut-off. Interestingly, performance on the AQ's imagination domain was inversely correlated with magnetoencephalography measures of resting-state functional connectivity in the right superior temporal gyrus. Individuals with AgCC should be screened for ASD and disorders of the corpus callosum should be considered in autism diagnostic evaluations as well.

Neuropsychological profile of agenesis of the corpus callosum: a systematic review.

Developmental absence (agenesis) of the corpus callosum (AgCC) is a common brain malformation that presents in isolation or in association with other conditions. Variability in aspects of neuropsychological functioning has been reported in small samples of individuals. This study aimed to systematically review the literature to characterize the profile and severity of cognitive impairments in individuals with AgCC across development. A mean general intellectual ability was calculated and neuropsychological functioning was qualitatively examined. We discuss methodological limitations of the literature, inherent heterogeneity of the causes and comorbidities of AgCC, and the developmental aspect of AgCC in opposition to "split-brain patients."

Decision-making in individuals with agenesis of the corpus callosum: expectancy-valence in the Iowa Gambling Task.

Individuals with agenesis of the corpus callosum (ACC) can have intelligence within the normal range, but nevertheless have deficiencies in decision-making and complex novel problem-solving. The specific nature of these problems is not yet clearly understood. The Iowa Gambling Task was used to test decision-making ability and problem-solving in 40 individuals with complete or partial ACC (full-scale intelligence quotient >80) and 26 control participants. The expectancy-valence (EV) model was applied to the trial-by-trial responses of each participant to elucidate differences in decision processes utilized by each group. The ACC group had a lower overall net gain and fewer advantageous choices than controls, but these differences were not statistically significant. Within the EV model, individuals with ACC exhibited significantly higher attention to losses, less consistency in their choice strategy, and greater frequency of switching between decks. They also showed a tendency to be more influenced by recent trials. This outcome is similar to that seen in individuals with Asperger's disorder. Taken together, these results suggest that individuals with ACC have difficulty in inferring game contingencies and forming a coherent selection strategy, implicating the corpus callosum in these decision processes.