Agenesis of Corpus Callosum and Emotional Information Processing in Schizophrenia

Departement de Psychiatrie, Université de Montréal Montréal, QC, Canada.
Frontiers in Psychiatry 02/2012; 3:1. DOI: 10.3389/fpsyt.2012.00001
Source: PubMed


Corpus callosum (CC) is essential in providing the integration of information related to perception and action within a subcortico-cortical network, thus supporting the generation of a unified experience about and reaction to changes in the environment. Its role in schizophrenia is yet to be fully elucidated, but there is accumulating evidence that there could be differences between patients and healthy controls regarding the morphology and function of CC, especially when individuals face emotionally laden information. Here, we report a case study of a patient with partial agenesis of corpus callosum (agCC patient with agenesis of the anterior aspect, above the genu) and we provide a direct comparison with a group of patients with no apparent callosal damage (CC group) regarding the brain activity during the processing of emotionally laden information. We found that although the visual cortex activation in response to visual stimuli regardless of their emotional content was comparable in agCC patient and CC group both in terms of localization and intensity of activation, we observed a very large, non-specific and non-lateralized cerebral activation in the agCC patient, in contrast with the CC group, which showed a more lateralized and spatially localized activation, when the emotional content of the stimuli was considered. Further analysis of brain activity in the regions obtained in the CC group revealed that the agCC patient actually had an opposite activation pattern relative to most participants with no CC agenesis, indicating a dysfunctional response to these kind of stimuli, consistent with the clinical presentation of this particular patient. Our results seem to give support to the disconnection hypothesis which posits that the core symptoms of schizophrenia are related to aberrant connectivity between distinct brain areas, especially when faced with emotional stimuli, a fact consistent with the clinical tableau of this particular patient.

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Available from: Ovidiu Lungu, Sep 26, 2014
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    • "For example, the deficit in emotional awareness associated with the range of alexithymic traits in schizophrenia has been shown to relate to (reduced) white matter integrity within the corpus callosum, via language capacity (Kubota et al., 2012). Neurological patients with a damaged or absent corpus callosum also have trouble processing emotional information (Lungu and Stip, 2012), and the role of this structure may be especially important in social contexts, where the fast recognition of emotions seems to require inter-hemispheric cooperation , rather than hemispheric lateralisation (Tamietto et al., 2007). Due to the complexity of socio-cognitive functions like the interpretation of emotion cues, which requires the coordinated functioning of a widely distributed network of grey matter regions, it is possible that these socio-cognitive impairments may be caused by disrupted connectivity between grey matter regions (Miyata et al., 2010). "
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    ABSTRACT: Our ability to make sense of emotional cues is of paramount importance for understanding state of mind and communicative intent. However, emotional cues often conflict with each other; this presents a significant challenge for people with schizophrenia. We conducted a theoretical review to determine the extent and types of impaired processing of emotion-related conflict in schizophrenia; we evaluated the relationship with medication and symptoms, and considered possible mediatory mechanisms. The literature established that people with schizophrenia demonstrated impaired function: (i) when passively exposed to emotion cues whilst performing an unrelated task, (ii) when selectively attending to one source of emotion cues whilst trying to ignore interference from another source, and (iii) when trying to resolve conflicting emotion cues and judge meta-communicative intent. These deficits showed associations with both negative and positive symptoms. There was limited evidence for antipsychotic medications attenuating impaired emotion perception when there are conflicting cues, with further direct research needed. Impaired attentional control and context processing may underlie some of the observed impairments. Neuroanatomical correlates are likely to involve interhemispheric transfer via the corpus callosum, limbic regions such as the amygdala, and possibly dorsolateral prefrontal and anterior cingulate cortex through their role in conflict processing.
    Psychiatry Research 08/2014; 220(1-2). DOI:10.1016/j.psychres.2014.07.077 · 2.47 Impact Factor
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    • "Paul et al. described that despite having normal IQ, individuals with complete dysgenesis of the CC show impaired social intelligence, analyzing their responses to pictures from the Thematic Apperception Test [73]. Moreover, many studies have reported that major mental disorders, such as autism, attention deficit hyperactivity disorder (ADHD), and schizophrenia, may be related to the morphology of the CC [74–76]. However, the precise nature of these associations remains unclear. "
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    ABSTRACT: Numerous studies have investigated the formation of interhemispheric connections which are involved in high-ordered functions of the cerebral cortex in eutherian animals, including humans. The development of callosal axons, which transfer and integrate information between the right/left hemispheres and represent the most prominent commissural system, must be strictly regulated. From the beginning of their growth, until reaching their targets in the contralateral cortex, the callosal axons are guided mainly by two environmental cues: (1) the midline structures and (2) neighboring? axons. Recent studies have shown the importance of axona guidance by such cues and the underlying molecular mechanisms. In this paper, we review these guidance mechanisms during the development of the callosal neurons. Midline populations express and secrete guidance molecules, and "pioneer" axons as well as interactions between the medial and lateral axons are also involved in the axon pathfinding of the callosal neurons. Finally, we describe callosal dysgenesis in humans and mice, that results from a disruption of these navigational mechanisms.
    Neural Plasticity 02/2013; 2013(2):149060. DOI:10.1155/2013/149060 · 3.58 Impact Factor
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    Frontiers in Psychiatry 07/2012; 3:72. DOI:10.3389/fpsyt.2012.00072
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