Effects of subarachnoid hemorrhage on cerebral blood volume, blood flow, and oxygen utilization in humans

TLDR

Forty‑five studies of regional cerebral blood volume, flow, and oxygen utilization were performed in 30 patients undergoing diagnostic cerebral angiography for subarachnoid hemorrhage from ruptured aneurysms. Radioactive oxygen‑15 tracer techniques measured rCBV, rCBF, and rCMRO₂, and patients were grouped by neurological status and presence of cerebral vasospasm. SAH, with or without vasospasm, caused marked reductions in CBF and CMRO₂, especially in patients with severe deficits or vasospasm, while CBV rose 58 % above normal in those with severe deficits and vasospasm, indicating large‑vessel constriction coupled with intraparenchymal dilation.

Abstract

✓ Forty-five studies of regional cerebral blood volume (rCBV), regional cerebral blood flow (rCBF), and regional cerebral oxygen utilization (rCMRO 2 ) were performed in 30 patients undergoing diagnostic cerebral angiography for evaluation of a subarachnoid hemorrhage due to a ruptured intracranial aneurysm. Tracer methods employing radioactive oxygen-15 were used to measure rCBV, rCBF, and rCMRO 2 . The patient studies were divided into groups based on their neurological status and the presence or absence of cerebral vasospasm. Subarachnoid hemorrhage, with and without vasospasm, produced significant decreases in CBF and CMRO 2 . In general, patients with more severe neurological deficits, and patients with more severe degrees of vasospasm, had a more marked depression of CBF and CMRO 2 . The most striking finding was a significant (p < 0.001) increase in CBV (to 58% above normal) in patients with severe neurological deficits associated with severe cerebral vasospasm. This large increase suggests that cerebral vasospasm consists of constriction of the large, radiographically visible extraparenchymal vessels accompanied by a massive dilation of intraparenchymal vessels.