James Caldwell on The Hidden Culprit in Perimesencephalic SAH
James Caldwell, Interventional Neuroradiologist at Auckland City Hospital, shared on LinkedIn:
”When I went to school, I was taught that benign perimesencephalic subarachnoid hemorrhage (SAH) was most likely venous in origin—but the lack of direct evidence for a venous source always bothered me.
Later, I learned about basilar perforator aneurysms: “rare”, typically tiny aneurysms arising from basilar perforators that can present with SAH.
More recently, at our weekly neurovascular multidisciplinary meetings, we’ve repeatedly joked that “all” benign perimesencephalic hemorrhages are probably due to tiny or transient basilar perforator aneurysms that we never detect.
Well, some astute colleagues have shared a few compelling example cases at the page below – strongly recommend checking them out.
I read the page recently and it struck me like a chord.
What proportion of benign perimesencephalic SAH might be attributable to these lesions?
The page also highlights again what a valuable and deeply subspecialized resource neuroangio.org is.
Thank you to Maksim Shapiro et al!”
Find the full article here.

Stay updated on all scientific advances with Hemostasis Today.
-
May 30, 2026, 08:58Ben Creagh-Brown: How Should HI-PEITHO Influence the Management of Intermediate-Risk Pulmonary Embolism?
-
May 30, 2026, 08:56Reidiel Suárez Borges: Understanding the INR in Anticoagulation Management
-
May 29, 2026, 17:23Rita Schwab: Current Clinical Management of Trauma without the Use of Allogenic Blood Products
-
May 29, 2026, 17:22Brian Schiro: Excited to Provide Guideline Based Care at the Aortic Center
-
May 29, 2026, 17:20Martin Widschwendter: How Molecular Detection Tests Could Transform Endometrial Cancer Care
-
May 29, 2026, 17:18Nina Lansbury: Supporting a Period Friendly World With Menstrual Health Research and Education
-
May 29, 2026, 17:16Ipsita Chatterjee: Red is Not Shame, Red is Power, Red is a Woman
-
May 29, 2026, 16:49Abdulrahman Nasiri: The Evolving Role of Romiplostim in SAA
-
May 29, 2026, 16:46Soumen Bhattacharya: UC-II and Immune Modulation in Osteoarthritis