Basilar tip fenestration giving rise to Percheron's and mesencephalic arteries.

The basilar bifurcation region is a common site for intracranial aneurysms, as well as it gives rise to a group of perforating arteries that supply the mesencephalon and the thalamus. Complex vascular microanatomy poses a diagnostic and therapeutic challenge for neurosurgeons, neuroradiologists and neurologists. In this paper, we present a previously unreported case of basilar tip fenestration that gave rise to five perforating arteries: the artery of Percheron and four mesencephalic arteries. Due to invaluable clinical significance, the possibility of such a variant must be considered during performing various neurovascular procedures, since e.g., embolization of the fenestration misdiagnosed as an aneurysm would inevitably lead to severe neurological complications (consciousness disturbances, quadriplegia, and sensory loss). Comprehensive knowledge of the neuroanatomy and neuroembryology is crucial to safe execution of intracranial interventions.