Anton syndrome after subarachnoid hemorrhage and delayed cerebral ischemia: A case report

We report the case of a patient with ruptured middle cerebral artery aneurysm, subarachnoid hemorrhage and frontal intracerebral hemorrhage, who secondarily presented with delayed cerebral ischemia and bilateral occipital infarcts, with complete vision loss, visual anosognosia, and confabulations as the main symptoms. Additionally, the patient had defined features of Cotard syndrome, as revealed by persistent nihilistic delusions. The brain imaging studies showed a bilateral occipital ischemic lesion, as well as frontal and parietal hemorrhagic lesions in the right hemisphere. We address the general theories of anosognosia, confabulation and the problem of why a bilateral occipital lesion is not enough for these metacognitive defects to exist. The presence of right frontal and or parietal hemisphere lesions could be necessary features in most cases.