Transient prosopagnosia and lasting topographical disorientation after the total removal of a right occipital arteriovenous malformation

A 32-year-old right-handed female tour guide developed a transient prosopagnosia after the total removal of an arteriovenous malformation in the right occipital lobe. Neurological examination revealed only a left homonymous hemianopsia. The ablation on the right side involved total occipital lobe, the posterior region of the parahippocampal gyrus, and a part of the precuneus and angular gyrus. Neuropsychologically she was alert and oriented in time and place. No aphasia or apraxia was observed. Visual recognition of objects, colors and letters was normal. She could match faces and insects easily, despite a close resemblance among them. Her prosopagnosia resolved in one month, while her impairment in topographical orientation and nonverbal memory continued more than eight months. These findings exclude the possibility that her prosopagnosia was derived from visual agnosia, poor discrimination of details, or nonverbal memory deficit. Excluding cases with malignant brain tumor which may affect more diffuse area of the brain, there was only one reported case who developed persistent prosopagnosia after the right occipital lobectomy. Given the rarity of prosopagnosics with only right-sided lesions, it seems that in most of humans posterior parts of both hemispheres participate in the identification of faces.