Splenial Callosal Disconnection in Right Hemianopic Patients Induces Right Visual-Spatial Neglect.

Posterior cerebral artery (PCA) territory infarction involving occipital cortical damage can give rise to contralateral homonymous hemianopia. Here, we report two rare cases of patients with lesions in the left hemisphere PCA territory who developed right visuo-spatial neglect. One patient suffered right hemianopia and right visuo-spatial neglect after a stroke that damaged the left primary visual cortex and the callosal splenial fibers.

The Precentral Insular Cortical Network for Speech Articulation.

Apraxia of speech is a motor disorder characterized by the impaired ability to coordinate the sequential articulatory movements necessary to produce speech. The critical cortical area(s) involved in speech apraxia remain controversial because many of the previously reported cases had additional aphasic impairments, preventing localization of the specific cortical circuit necessary for the somatomotor execution of speech. Four patients with "pure speech apraxia" (i.

Selective visual neglect in right brain damaged patients with splenial interhemispheric disconnection.

Left unilateral neglect is frequently reported after right hemispheric lesions of the middle cerebral artery (MCA) damaging the parietal-frontal cortical-subcortical network subserving space representation and awareness. However, accumulating evidence shows that neglect can also follow lesions of the posterior cerebral artery (PCA) that do not directly affect this parietal-frontal network. Surgical studies in the monkeys have demonstrated that complete callosal resection combined with lesion of the right optic tract entirely deprives the right hemisphere of visual inputs from the left hemispace provoking severe left unilateral neglect.