cerebral steal phenomenon
Pathological redistribution of cerebral blood flow away from ischemic brain regions toward areas with intact vascular reactivity.
Full Definition
Cerebral steal phenomenon describes the paradoxical reduction in blood flow to ischemic or hypoperfused brain regions when vasodilation is induced pharmacologically or by increased carbon dioxide levels. In healthy brain tissue, vasodilation appropriately increases local perfusion. However, in areas with compromised autoregulation or maximally dilated vessels, vasodilation in adjacent healthy regions can divert blood flow away from the compromised areas, potentially worsening ischemia. This phenomenon is particularly relevant in patients with cerebrovascular disease, where interventions intended to improve perfusion may inadvertently worsen regional ischemia. The concept is important for understanding the effects of vasodilatory medications and hypercarbia in neurocritical care patients.
Usage
Usage note: Sometimes incorrectly called 'Robin Hood phenomenon,' which actually refers to the opposite effect. Editors should verify correct usage.
In Context
- "The patient developed cerebral steal phenomenon following administration of vasodilatory agents." — Neurocritical care progress note
- "Monitoring revealed evidence of steal phenomenon with worsening regional perfusion despite improved global cerebral blood flow." — Research study