What is the mechanism of cerebral vasospasm at a molecular level?
“Cerebral vasospasm” is a term that refers to physical narrowing of the central “lumen” of a brain blood vessel due to overcontraction of the vessel wall (see Figure 1, below). Here, “cerebral” refers to the brain, while “vaso” refers to blood vessel and “spasm” refers to the vessel’s “spastic” or “shut down” or “constricted” physical state. In the worst-case scenario, a vasospastic brain artery is so shut down it no longer permits blood flow as its central “lumen” no longer exists, a state that can be likened to a tightly clenched fist. Cerebral Vasospasm: Figure 1 shows how, in cerebral vasospasm, a brain artery which was once normal in terms of its diameter, ends up overcontracting, i.e., becoming “spastic”. The central lumen of the artery which normally permits the free flow of blood becomes very narrow and may even entirely shut down in vasospasm. Cerebral vasospasm generally occurs due to a ruptured brain aneurysm, or (very rarely) hemorrhage from another blood vessel abnormality
