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Updated: Jul 11, 2026

Endovascular Perforation Model for Subarachnoid Hemorrhage Combined with Magnetic Resonance Imaging (MRI)
Published on: December 16, 2021
Midbrain stroke with angiogram-negative subarachnoid hemorrhage mimicking a perimesencephalic bleed
1Department of Neurology, Walter Reed Army Medical Center, Washington, DC, USA.
Abstract:
Angiogram-negative atraumatic subarachnoid hemorrhage (SAH) in a perimesencephalic pattern on computed tomography (CT) is associated with an almost invariably favorable prognosis with few rebleeds. We report a patient who exhibited a perimesencephalic hemorrhage pattern on CT and negative serial angiograms and who presented with severe neurologic disability from a concurrent midbrain stroke. We contend that both the acute infarction and hemorrhage arose from obliteration of a penetrating end artery. Possible etiologies of angiogram-negative SAH, including perimesencephalic hemorrhage, are discussed.
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