[Unruptured aneurysm arising from fenestration of the horizontal (A1) segment in the anterior cerebral artery: a case report and review of the literature].

Cerebral aneurysms arising from fenestration of the horizontal (A(1)) segment in the anterior cerebral artery (ACA) are very rare. In this paper, we report our case, discuss radiological features, and review previous cases. A 70-year-old male was referred to our hospital presenting with memory disturbance.