Subcallosal artery stroke: infarction of the fornix and the genu of the corpus callosum. The importance of the anterior communicating artery complex. Case series and review of the literature.

INTRODUCTION: Despite the variable anatomy of the anterior communicating artery (AcoA) complex, three main perforating branches can be typically identified the largest of which being the subcallosal artery (ScA). We present a case series of infarction in the vascular territory of the ScA to highlight the anatomy, the clinical symptomatology, and the presumed pathophysiology as it pertains to endovascular and surgical management of vascular pathology in this region.
METHODS: In this retrospective multicenter case series study of patients who were diagnosed with symptomatic ScA stroke, we analyzed all available clinical records, MRI, and angiographic details. Additionally, a review of the literature is provided.
RESULTS: We identified five different cases of ScA stroke, leading to a subsequent infarction of the fornix and the genu of the corpus callosum. The presumed pathophysiology in non-iatrogenic cases is microangiopathy, rather than embolic events; iatrogenic SCA occlusion can present after both surgical and endovascular treatment of AcoA aneurysms that may occur with or without occlusion of the AcoA.
CONCLUSION: Stroke in the vascular territory of the ScA leads to a characteristic imaging and clinical pattern. Ischemia involves the anterior columns of the fornix and the genu of the corpus callosum, and patients present with a Korsakoff's syndrome including disturbances of short-term memory and cognitive changes. We conclude that despite its small size, the ScA is an important artery to watch out for during surgical or endovascular treatment of AcoA aneurysms.