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Updated: Aug 12, 2026

Double Direct Injection of Blood into the Cisterna Magna as a Model of Subarachnoid Hemorrhage
Published on: August 30, 2020
Human cardiovascular evolution and intracranial saccular aneurysms: an hypothesis
1Department of Anesthesiology, Hospital of the University of Pennsylvania, Philadelphia, USA.
Abstract:
Current predominant theories for the pathogenesis of intracranial saccular aneurysms have a congenital or a degenerative basis. Complementing these theories, the predilection of intracranial aneurysms for the human species has been attributed to a variety of human neurovascular morphological traits, which however, on closer scrutiny are not unique to the human species. Human evolution to a bipedal primate has required significant adaptation in several organ systems, with significant consequent biological costs. We hypothesize that susceptibility to intracranial aneurysms is part of this latter cost of adopting an upright stance with respect to the neurovascular systems. Evidence supporting the above hypothesis, is presented.
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