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Cognitive, Emotional, and Behavioral Issues Journal Articles
Bedeschi, M. F. et al. Agenesis of the corpus callosum: clinical and genetic study in 63 young patients. Pediatr Neurol 34, 186-93 (2006).
This study reports the clinical features of 63 patients with agenesis of the corpus callosum who received in-depth genetic, clinical, and laboratory testing with the aim to contribute to a better description of the large spectrum of associated malformations and to assist clinicians in the diagnosis. Thirty patients manifested complete agenesis and 33 patients displayed partial agenesis. Other associated nervous system malformations were detected in 14 patients with partial agenesis of the corpus callosum (mostly correlated to posterior fossa malformations) and in 10 patients with complete agenesis (more frequently associated with malformations of cortical development). Involvement of organs and apparatus other than the nervous system was present in 41 patients (ascribed to known syndromes in 21 cases). Cytogenetically detectable chromosomal abnormalities (7 patients) and subtelomeric rearrangements (3 patients) were found. Neuromotor skills were impaired in almost all cases (58/63). Mental retardation of different severity was present in 52 cases, whereas 2 patients were borderline and 9 patients had normal intelligence quotient. This study demonstrates that there is no unique prognosis for agenesis of the corpus callosum as this condition is associated with a broad range of clinical manifestations, oscillating between the limits of the norm and severe psychomotor delay.
Brown, W. S. & Paul, L. K. Cognitive and psychosocial deficits in agenesis of the corpus callosum with normal intelligence. Cognitive neuropsychiatry 5, 135-157 (2000).
Presents two case studies of the cognitive and psychosocial abilities of individuals with agenesis of the corpus callosum (ACC) and normal intelligence to further evaluate the hypothesis that ACC is associated with specific problems in complex cognitive operations. Cognitive and psychosocial deficits were studied in two males aged 16-18 yrs & 21-23 yrs at time of testing, with ACC and normal IQ, using a battery of cognitive and psychological tests. Test results indicated poor interhemispheric integration of complex material. Performance on tests of reasoning and concept formation was clearly below expectations based on IQ. Significantly poor performance was also found on tests of social insight, proverb interpretation, social logic, self-perception, and interpretation of ambiguous stimuli. Gross behavioural disorder or psychopathology were not found. ACC results in disabilities in social cognition that appear to be secondary to deficits in complex cognitive operations such as reasoning, concept formation, and problem solving. These cognitive deficits may be related to diminished interhemispheric transfer of complex information. (PsycINFO Database Record (c) 2006 APA, all rights reserved.
Brown, W. S., Paul, L. K., Symington, M. & Dietrich, R. Comprehension of humor in primary agenesis of the corpus callosum. Neuropsychologia 43, 906-16 (2005).
Individuals with agenesis of the corpus callosum (ACC) can, in some cases, perform normally on standardized intelligence tests. Nevertheless, recent studies suggest that individuals with ACC and normal IQ scores have deficits in domains of fluid and social intelligence. Anecdotal reports from families suggest diminished appreciation of the subtleties of social interactions, and deficits in the comprehension of jokes and stories. In this research, both the cartoon and narrative joke subtests of a humor test (developed by Brownell et al. [Brownell, H., Michel, D., Powelson, J., & Gardner, H. (1983). Surprise but not coherence: sensitivity to verbal humor in right-hemisphere patients. Brain and language, 18(1), 20-27] and Bihrle et al. [Bihrle, A. M., Brownell, H. H., Powelson, J. A., & Gardner, H. (1986). Comprehension of humorous and non-humorous materials by left and right brain-damaged patients. Brain and Cognition, 5(4), 399-411]) were given to 16 adults with complete ACC (all with IQs>80) and 31 controls of similar age and IQ. Individuals with ACC performed worse than controls on the narrative joke subtest (p<.025) when VIQ was controlled. However, on the cartoon subtest the two groups were not significantly different. Covarying age, forms of IQ, narrative memory, set-switching, and literal language comprehension did not substantially alter the group difference. However, covarying comprehension of nonliteral language and proverbs eliminated the difference, suggesting a common origin for the comprehension of jokes, nonliteral language, and proverbs, most likely related to capacity for understanding second-order meanings.
Brown, W. S., Symington, M., Van Lancker-Sidtis, D., Dietrich, R. & Paul, L. K. Paralinguistic processing in children with callosal agenesis: emergence of neurolinguistic deficits. Brain and Language 93, 135-139 (2005).
Recent research revealed impaired processing of both nonliteral meaning and affective prosody in adults with agenesis of the corpus callosum (ACC) and normal intelligence. Since normal children have incomplete myelination of the corpus callosum, it was hypothesized that paralanguage deficits in children with ACC would be less apparent relative to their peers. The Familiar and Novel Language Comprehension Test (FANL-C) and Prosody Test were given to 18 children with ACC and normal intelligence and 17 controls matched for age (7-13 years), education, and IQ (83-122). When controlling for age, children with ACC were significantly poorer in comprehension of the precise meaning of both literal and nonliteral items on the FANL-C. Adults with ACC had previously been shown to have difficulty only on nonliteral items. The effect size for nonliteral comprehension in children with ACC was smaller than that seen in adults. There was only a trend for the child ACC group to perform worse on the recognition of affective prosody. Thus, while deficits in paralinguistic processing were apparent, children with ACC were not as clearly different from age peers as adults, and were equally deficient at comprehending literal and nonliteral expressions. The differences in results between adults and children with ACC are thought to reflect incomplete callosal development in normal children, and the importance of the corpus callosum in the early stages of the development of the ability to process literal language.
Chiarello, C. A house divided? Cognitive functioning with callosal agenesis. Brain and Language 11, 128-158 (1980).
Presents an anatomical and behavioral review of 29 reported cases (aged 7-48 yrs) of corpus callosum agenesis. Unlike the commissurotomy cases, acallosals show few symptoms of hemispheric disconnection. Behavioral strategies, use of noncallosal commissures, elaboration of ipsilateral pathways, and bilateral representation of function are discussed and evaluated as possible mechanisms of compensation. An impairment in spatiomotor functioning often accompanies callosal agenesis. Results of acallosal lateralization testing are examined, and problems in interpretation are discussed. Current evidence does not conclusively establish that the corpus callosum is needed for lateralization development of some functions. However, the corpus callosum may play a role in the satisfactory performance of "lateralized" (i.e., spatial, linguistic) functions. (4½ p ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved)
Dennis, M., Language in a congenitally acallosal brain. Brain and Language 12, 33-53, (1981).
The case of a 27-yr-old female with complete callosal agenesis shows 2 limitations of cognitive development. The first, a discrete loss of syntactic-pragmatic function within the language domain, may or may not be associated with anomalous cerebral lateralization of speech and language; its neural basis is unknown. The 2nd deficit, an inability to identify free-field or dichotic speech sounds with overlapping temporal-acoustic properties, appears due to a nonlinguistic limitation of the acallosal brain, the inability to suppress ipsilateral information. (29 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved)
Doherty, D., Tu, S., Schilmoeller, K. & Schilmoeller, G. Health-related issues in individuals with agenesis of the corpus callosum. Child Care Health Dev 32, 333-42 (2006).
OBJECTIVES: To explore and compare the prevalence and expression of specific health-related variables in a large survey sample of persons with agenesis of the corpus callosum (ACC) and their siblings. METHODS: Caregiver surveys of individuals with ACC (n=189) and their siblings (n=189) provided data regarding diagnoses, physical features, neurological and sensory information, feeding, elimination and sleep concerns, and some behavioural features. RESULTS: Compared with their siblings, individuals with ACC had more concurrent conditions and were more likely to have altered pain perception and sensitivity to touch. In addition, individuals with ACC had more sensory deficits and abnormalities as well as altered patterns of feeding/eating, elimination and sleep. CONCLUSIONS: These data raise important questions for future research and suggest the need for increased vigilance by caregivers and health-care professionals of individuals with callosal disorders. Early detection and intervention may help prevent or ameliorate health problems in this population.
Ettlinger, G., et al., Agenesis of the corpus callosum: a behavioural investigation. Brain 95, 327-346 (1972).
Compared 4 patients with total agenesis of the corpus callosum, 4 with partial agenesis, and 4 control subjects. The total group was somewhat impaired on matching density of dot fields between the half fields and on crossed tactile localization, but were largely normal on all other tasks. The findings are felt to accord with the view that imperfect noncallosal commissures are used in agenesis. (PsycINFO Database Record (c) 2006 APA, all rights reserved)
Finlay, D.C., Peto, T., Payling, J., Hunter, M., Fulham, W.R. & Wilkinson, I. A study of three cases of familial related agenesis of the corpus callosum. Journal of Clinical and Experimental Neuropsychology 22, 731-42 (2000).
This paper provides data on a family in which three members, all female, have been diagnosed as having agenesis of the corpus callosum. That all three acallosal individuals came from the same family and showed relatively uniform neuropsychological impairment and could be compared in similar terms with their "callosal" siblings, also female, provides a unique sample. Inter-hemispheric transfer, psychometric measures, and motor and cognitive function were examined in the acallosal individuals, all of whom had borderline to low-average intelligence, with results compared to their non-acallosal siblings. The data indicated that all acallosal individuals exhibited deficits with the cognitive tests indicating difficulties of inter-hemispheric transfer of tactile information, difficulties in some areas of memory and, at least as far as the children are concerned, a marked difference in Verbal IQ and Performance IQ.
Hines, R.J., L.K. Paul, and W.S. Brown, Spatial Attention in agenesis of the corpus callosum: Shifting attention between visual fields. Neuropsychologia 40, 804-1814 (2002).
The role of the corpus callosum in spatially selective visual attention is uncertain. Research using commissurotomy and callosotomy patients has attempted to determine if the corpus callosum plays a role in reorienting attention between visual fields, as if spatial attention is unitary or divisible between the cerebral hemispheres. Reorienting of selective visuospatial attention within versus between visual fields was tested in 10 individuals with agenesis of the corpus callosum (ACC) and nine matched controls. Spatially focused attention to the most likely location of target appearance was created using both peripheral sensory cues and central symbolic cues in separate tests. Results demonstrated that individuals with ACC have significantly greater difficulty reorienting attention to an invalidly cued target stimulus occurring in the opposite visual field. However, this effect did not interact with the type of cueing (sensory or symbolic). Individuals with ACC did not differ from controls either with respect to the laterality of within-field reorientation of attention, or with respect to the most efficient direction of between-field shifting of attention. Since congenital absence of the corpus callosum significantly reduces efficiency in the reorienting of attention between visual fields, spatial attention cannot be completely unified based on a subcortical mechanism and the mobilization of attentional resources within each hemisphere must depend on callosal processes.
Huber-Okrainec, J., Blaser, S. E. & Dennis, M. Idiom comprehension deficits in relation to corpus callosum agenesis and hypoplasia in children with spina bifida meningomylocele. Brain and Language 93, 349-368 (2005).
Idioms are phrases with figurative meanings that are not directly derived from the literal meanings of the words in the phrase. Idiom comprehension varies with: literality, whether the idiom is literally plausible; compositionality, whether individual words contribute to a figurative meaning; and contextual bias. We studied idiom comprehension in children with spina bifida meningomyelocele (SBM), a neurodevelopmental disorder associated with problems in discourse comprehension and agenesis and hypoplasia of the corpus callosum. Compared to age peers, children with SBM understood decomposable idioms (which are processed more like literal language) but not non-decomposable idioms (which require contextual analyses for acquisition). The impairment in non-decomposable idioms was related to congenital agenesis of the corpus callosum, which suggests that the consequences of impaired interhemispheric communication, whether congenital or acquired in adulthood, are borne more by configurational than by compositional language.
Jeeves, M.A. and C.M. Temple, A further study of language function in callosal agenesis. Brain and Language 32, 325-335 (1987).
A subset of the tests of language ability administered by M. Dennis (1981, Brain and Language, 12, 33-53) was given to two adult acallosal patients. One of the patients studied showed widespread language deficits not restricted to the syntactic-pragmatic core as in Dennis' patient. The other showed a very specific deficit which does not encompass syntactic-pragmatic skills. The data does not support the view that the corpus callosum is necessary for the normal development of specific language functions.
Meerwaldt, J.D., Disturbances of spatial perception in a patient with agenesis of the corpus callosum. Neuropsychologia 21, 161-165 (1983).
An 8-yr-old girl with agenesis of the corpus callosum was tested with the rod orientation test. Test results were compared with those of 10 neurologically normal children (7-9 yrs old). S had a defective performance and the longest mean duration in the tactile part of the test but only when using her right hand. Results are in accord with a diagnosis of a disturbed interhemispheric transfer of tactile information. (French & German abstracts) (2 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved)
Ng, Y.T. McCarthy, C.M., Tarby, T.J., Bodensteiner, J.B. Agenesis of the corpus callosum is associated with feeding difficulties. Journal of Child Neurology 19, 443-446 (2004).
OBJECTIVE: To report two children, with normal intelligence, referred for evaluation of complex cognitive, behavioral, and psychiatric problems, in which Agenesis of Corpus Callosum (ACC) was an incidental finding. METHOD: Case descriptions are used and a comprehensive differential diagnosis made with previous diagnoses of partial complex seizures (PCS), psychosis, anxiety, attention deficit hyperactivity disorder (ADHD), and behavior disorder. RESULTS: Due to the presence of multiple biopsychosocial interactions a multimodal intervention including pharmacological, behavioral, psychotherapeutic, and social approaches was implemented, with good results. CONCLUSION: These cases underscore the importance of conducting a comprehensive neuropsychiatric evaluation in children with severe behavior problems and other confusing symptoms. Since the incidence of ACC in behaviorally disturbed children, with normal intelligence, is unknown, physicians must accept that a reasonable degree of suspicion is warranted. Further studies are needed to facilitate physicians' awareness.
Paul, L.K., Lautzenhiser, A., Brown, W.S., Hart, A., Neumann, D., Spezio, M., and Adolphs, R. Emotional Arousal in Agenesis of the Corpus Callosum. International Journal of Psychophysiology. 61, 47-56 (2006).
While the processing of verbal and psychophysiological indices of emotional arousal have been investigated extensively in relation to the left and right cerebral hemispheres, it remains poorly understood how both hemispheres normally function together to generate emotional responses to stimuli. Drawing on a unique sample of nine high-functioning subjects with complete agenesis of the corpus callosum (AgCC), we investigated this issue using standardized emotional visual stimuli. Compared to healthy controls, subjects with AgCC showed a larger variance in their cognitive ratings of valence and arousal, and an insensitivity to the emotion category of the stimuli, especially for negatively-valenced stimuli, and especially for their arousal. Despite their impaired cognitive ratings of arousal, some subjects with AgCC showed large skin-conductance responses, and in general skin-conductance responses discriminated emotion categories and correlated with stimulus arousal ratings. We suggest that largely intact right hemisphere mechanisms can support psychophysiological emotional responses, but that the lack of interhemispheric communication between the hemispheres, perhaps together with dysfunction of the anterior cingulate cortex, interferes with normal verbal ratings of arousal, a mechanism in line with some models of alexithymia.
Paul, L. K., Schieffer, B. & Brown, W. S. Social processing deficits in agenesis of the corpus callosum: Narratives from the Thematic Apperception Test. Archives of Clinical Neuropsychology 19, 215-225 (2004).
Clinical observations suggest that individuals with agenesis of the corpus callosum (ACC) and normal IQ may have deficits in social intelligence. This study analyzed responses by normally intelligent individuals with ACC to pictures from the Thematic Apperception Test. A rating system was developed to assess three elements of story-generation: story logic, social understanding, and common content. Six individuals with ACC (five complete and one partial; IQs > 85) were compared to eight controls matched for sex, age, and IQ. Based on independent rankings of story protocols by two raters, the five individuals with complete ACC were found to be significantly impaired on all three criteria. The one individual with partial ACC performed better than the majority of controls in all three domains. Results demonstrated that individuals with complete ACC are impaired in understanding socially complex scenes and generating appropriate narratives. Absence of the anterior corpus callosum appears to be important for this deficit.
Paul, L. K., Van Lancker-Sidtis, D., Schieffer, B., Dietrich, R. & Brown, W. S. Communicative deficits in agenesis of the corpus callosum: nonliteral language and affective prosody. Brain Lang 85, 313-24 (2003).
While some individuals with agenesis of the corpus callosum can perform normally on standardized intelligence tests, clinical observations suggest that they nevertheless have deficits in the domains of fluid and social intelligence. Particularly important for social competence is adequate understanding and use of paralinguistic information. This study examined the impact of callosal absence on the processing of pragmatic and paralinguistic information. Young adult males with agenesis of the corpus callosum (ACC) were evaluated in the areas of nonliteral language comprehension, proverb recognition and interpretation, and perception of affective prosody. Ten ACC individuals with normal Wechsler IQ were compared to 14 sex, age, and IQ matched normal controls. The Formulaic and Novel Language Comprehension Test (FANL-C), Gorham Proverbs Test, and LA Prosody Test were administered. ACC subjects exhibited significant impairment on the nonliteral items of the FANL-C, but no significant difference from controls in comprehension of literal items. ACC subjects also exhibited significant deficits in both self-generated interpretation and recognition of proverb meaning, and in recognition of affective prosody. These results demonstrate that normally intelligent individuals with ACC are impaired in the understanding of nonliteral language and emotional-prosodic cues that are important in social communication. In all three tests, the performance of individuals with ACC was similar to patients with right hemisphere brain damage. Thus, persons with ACC appear to lack interhemispheric integration of critical aspects of language processed by the right hemisphere.
Redefer, L.A., & Goodman, J.F. (1989). Brief report: Pet-facilitated
therapy with autistic children. Journal of Autism and Developmental
Disorders. September: 19(3): 461-467.
Shevell, M. I. Clinical and diagnostic profile of agenesis of the corpus callosum. J Child Neurol 17, 896-900. (2002).
This study reports the clinical profile, etiologies identified, and outcomes for a consecutive series of children with partial or complete agenesis of the corpus callosum. Children with agenesis of the corpus callosum were identified in a comprehensive computerized database of all patients seen in a single pediatric neurology practice over an 11-year interval. Medical records were then systematically reviewed. Twenty-four children with agenesis of the corpus callosum were identified of a total of 6911 children in the database (0.35%). Fifteen were male (62.5%); 9 (37.5%) had presented antenatally, 6 (25%) neonatally, and 9 (37.5%) postneonatally. Eight (33.3%) were microcephalic, 12 (50%) were dysmorphic, 11 (45.8%) had coexisting epilepsy, and 9 (37.5%) had a cerebral palsy variant. Investigations revealed an etiology in 11 (45.8%): 3 chromosomal abnormality, 3 metabolic disorder, 3 cerebral dysgenesis, and 2 genetic syndromes (Aicardi, Andermann). Outcomes identified included normal or mild developmental delay in 7 (29.2%) and moderate-severe developmental delay in the remaining 17 (70.8%). Factors predictive of successful etiologic determination on bivariate analysis included moderate-severe developmental delay or associated cerebral dysgenesis. Factors predictive of eventual developmental outcome included microcephaly, coexisting epilepsy, cerebral palsy, or cerebral dysgenesis. A spectrum of clinical presentations, underlying etiology, and developmental outcome is thus apparent in children with agenesis of the corpus callosum. An underlying etiology can be identified in slightly less than half of cases, and a normal or mildly delayed outcome is apparent in slightly less than a third. Factors predictive of identifying an underlying etiology or eventual outcome can be identified.
Stickles, J. L., Schilmoeller, G. L. & Schilmoeller, K. J. A 23-year review of communication development in an individual with agenesis of the corpus callosum. International Journal of Disability, Development and Education 49, 367-383 (2002).
Twenty-three years of observation and testing of the communication skills of a male with agenesis of the corpus callosum and normal IQ revealed initial weakness in language. Difficulties with fluent speech persisted into young adulthood. With intensive intervention, communication and academic skills developed and the participant completed high school. (Contains references.) (Author/CR)
Temple, C. M. & Ilsley, J. Phonemic discrimination in callosal agenesis. Cortex 29, 341-348 (1993).
Children with callosal agenesis have congenital absence of the corpus callosum. Previous analyses of these subjects have shown that they have significant difficulty on rhyming tasks and tasks of explicit sound organisation. This study investigated whether such difficulties were also manifested on simpler tasks requiring the discrimination and repetition of similar sounding linguistic material. None of the acallosal children tested performed at a normal level across tasks. This suggests a possible impairment in the initial registration or analysis of auditory material and possible bases for this deficit are discussed. In cases of callosal agenesis in which impairments in auditory discrimination are more severe there may be a more profound impact upon language development.
Temple, C. M., Jeeves, M. A. & Vilarroya, O. Reading in callosal agenesis. Brain and Language 39, 235-253 (1990).
It has been suggested that deficits in explicit phonological processing are causal in developmental dyslexia. Deficits in such skills have been reported in developmental phonological dyslexia, though not in developmental surface dyslexia. The reading performance of two children with callosal agenesis, who have been previously shown to have impairments on rhyming tasks, are reported. Neither child is dyslexic in the traditional sense, since word reading levels are appropriate for age. However, both children have impaired development of the phonological reading route despite normal lexical skills. The pattern of their reading is therefore comparable to developmental phonological dyslexia. Problems in explicit phonological processing may be causal in the failure to establish an efficient phonological reading route but this is insufficient to create difficulty with word recognition itself. The corpus callosum may be essential for the normal development of a phonological reading route.
Temple, C. M., Jeeves, M. A. & Vilarroya, O. Ten pen men: Rhyming skills in two children with callosal agenesis. Brain and Language 37, 548-564 (1989).
Cases of callosal agenesis provide unique opportunities to investigate the normal role of the corpus callosum in the development of cognitive functions, including language. The only language impairment which has been consistently observed in three acallosal patients is on the retrieval of words from rhyming cues. Two new cases of callosal agenesis in children of normal intelligence are presented. Their performance on a variety of rhyming tasks involving both production and recognition of rhyme is reported. Both children display deficits and possible explanations are discussed.
Books or Book Chapters
O'Brien, G., The Behavioral and Developmental Consequences of Callosal Agenesis, in Callosal agenesis: A natural split brain? (eds. Lassonde, M. & Jeeves, M. A.) 235-246 (Plenum, New York, 1994).
Sauerwein, H.C., P. Nolin, and M. Lassonde, Cognitive functioning in callosal agenesis, in Callosal agenesis: A natural split brain? (eds. Lassonde, M. & Jeeves, M. A.) 221-233 (Plenum, New York, 1994).
Njiokiktjien, C., Absence of the corpus callosum: Clinicopathological correlations, in Pediatric behavioural neurology: The child's corpus callosum, (eds. Ramaekers, G. & Njiokiktjien, C.) 235 - 250 (Suyi Publicaties, Amsterdam, 1991).
Jeeves, M.A., Psychological studies of the three cases of congenital agenesis of the corpus callosum, in Functions of the Corpus Callosum: CIBA Foundations Study Groups (ed. Ettlinger, E.G.) 73-94 (Churchill, London, 1965).
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