Isolated Frontopolar Cortex Lesion: A Case Study

Background: The frontopolar cortex has been proposed to mediate prospective memory functioning, multitasking, relational integration, processing of internal states, and self-referential evaluation. These theories are based primarily on functional activation studies. The few lesion models reported have not been restricted to the frontopolar cortex. Aim: We used neuropsychological tests and neuroimaging to study an otherwise healthy woman with an isolated hemorrhagic infarct in the frontopolar cortex. Methods: In addition to a standard stroke work-up, the patient had cognitive psychometric tests reflecting the theoretical frontal functions of initiation, monitoring, inhibition, and working memory, as well as a test for emotional intelligence. Results: The midline frontopolar intracerebral hemorrhage was isolated, free of other pathology, and almost solely within Brodmann area 10. The only psychometric abnormalities concerned awareness of, understanding, and expressing emotions. Conclusions: This report may be the first of an isolated bilateral lesion of the frontopolar cortex, Brodmann area 10, with uniformly normal frontal lobe tests except for 2 abnormal findings of emotional intelligence. This lesion study supports the proposal that the medial frontopolar cortex is necessary for emotional processing of internal states.