Vertebral Artery Dissection Leading to Fornix Infarction: A Case Report.

Background: The subcallosal artery is a proximal branch of the anterior communicating artery and has been recognized as the vessel responsible for fornix infarction. Fornix infarction caused by vascular damage to the posterior circulation has not been reported previously.

Results: A 26-year-old woman suffered from fornix infarction due to artery-to-artery embolism after vertebral artery dissection. Cerebral infarctions were also found in the left thalamus, body of the left caudate nucleus, and the left occipital lobe other than the fornix.

Conclusions: Occlusion of the subcallosal artery results in cerebral infarction of fornix, anterior cingulate cortex, and genu of the corpus callosum. However, in our case, lesions were restricted to the territory of posterior circulation. In addition to subcallosal artery, lateral posterior choroidal artery, a perforating branch of the posterior cerebral artery, has been described to send branches to the fornix, so we speculated that the left lateral posterior choroidal artery was actually responsible for fornix infarction.