Search Results (4)

Striking belief distortions may accompany various disorders of awareness that are predominantly associated with right hemispheric cerebral dysfunction. Distortions may range on a continuum of pathological severity, from the unawareness of paralysis in anosognosia for hemiplegia, to a more startling disturbance in denial of paralysis where belief may starkly conflict with reality. The patients’ beliefs about their limitations typically represent attempts to make sense of limitations or to impart meaning to incongruous facts. These beliefs are often couched in recollections from past memories or previous experience, and are hard to modify even given new information. Various explanations of unawareness have been suggested, including sensory, cognitive, monitoring and feedback operations, feedforward mechanisms, disconnection theories, and hemispheric asymmetry hypotheses, along with psychological denial, to account for the curious lack of awareness in anosognosia and other awareness disorders. This paper addresses these varying explanations of the puzzling beliefs regarding hemiparesis in anosognosia. Furthermore, using the multi-dimensional nature of unawareness in anosognosia as a model, some startling belief distortions in other right-hemisphere associated clinical syndromes are also explored. Other neurobehavioral disturbances, though perhaps less common, reflect marked psychopathological distortions. Startling disorders of belief are notable in somatic illusions, non-recognition or delusional misattribution of limb ownership (asomatognosia, somatoparaphrenia), or delusional identity (Capgras syndrome) and misidentification phenomena. Difficulty in updating beliefs as a source of unawareness in anosognosia and other awareness disorders has been proposed. Processes of belief development are considered to be patterns of thought, memories, and experience, which coalesce in a sense of the bodily and personal self. A common consequence of such disorders seems to be an altered representation of the self, self-parts, or the external world. Astonishing nonveridical beliefs about the body, about space, or about the self, continue to invite exploration and to stimulate fascination. Full article

Anosognosia for hemiplegia is a complex, multifaceted phenomenon. Due to the various different forms in which it manifests and the few tools available to treat it, it can create difficulties for both clinicians and researchers. Since the first definition established by Babinski, a great deal of research has been performed and has shown that this deficit in motor awareness involves not only motor aspects but also other, non-motor dimensions. These dimensions all need to be taken into consideration during the process of diagnosis, in particular when planning a rehabilitation programme. This article reviews the main instruments currently available for the diagnosis of anosognosia for hemiplegia. After a description of the best tests to assess motor dimensions (such as explicit and implicit anosognosia, emergent awareness and awareness for daily life activities), non-motor dimensions are analysed. The literature on the subject provides ideas and tools for the evaluation of cognitive (i.e., motor imagery), emotional and social (i.e., theory of mind) aspects. Finally, the importance of differential diagnoses in relation to disorders often associated with anosognosia is discussed. Full article

This review aimed to evaluate whether the association between ‘anosognosia for hemiplegia’ and lesions of the right hemisphere points to a special self-awareness role of the right side of the brain, or could instead be due to a working mode typical of the right hemisphere. This latter viewpoint is consistent with a recently proposed model of human brain asymmetries that assumes that language lateralization in the left hemisphere might have increased the left hemisphere’s level of consciousness and intentionality in comparison with the right hemisphere’s less conscious and more automatic functioning. To assess these alternatives, I tried to ascertain whether anosognosia is greater for left-sided hemiplegia than for other disorders provoked by right brain lesions, or whether unawareness prevails in tasks more clearly related to the disruption of the right hemisphere’s more automatic (and less conscious) functioning. Data consistent with the first alternative would support the existence of a specific link between anosognosia for hemiplegia and self-awareness, whereas data supporting the second option would confirm the model linking anosognosia to a poorly conscious working mode typical of the right hemisphere. Analysis results showed that the incidence of anosognosia of the highly automatic syndrome of unilateral neglect was greater than that concerning the unawareness of left hemiplegia, suggesting that anosognosia for left-sided hemiplegia might be due to the poorly conscious working mode typical of the right hemisphere. Full article

A woman had anosognosia for hemiplegia as a manifestation of brainstem infarction. She had no mental or neuropsychological disturbances, and had involvement of the brainstem in the frontal/parietal-subcortical circuits to the right cerebral hemisphere. Brainstem lesions that disrupt frontal/parietal-subcortical areas may affect anosognosia for hemiplegia. Full article