Vasal Spasm

Vasospasm refers to a condition in which blood vessels spasm, leading to vasoconstriction. This can lead to tissue ischemia and death (necrosis). Cerebral vasospasm may arise in the context of subarachnoid hemorrhage. Symptomatic vasospasm or delayed cerebral ischemia is a major contributor to post-operative stroke and death after aneurysmal subarachnoid hemorrhage. Vasospasm typically appears 4 to 10 days after subarachnoid hemorrhage.

Vasoconstriction is the narrowing of the blood vessels resulting from contracting of the muscular wall of the vessels. When blood vessels constrict, the flow of blood is restricted or slowed. It is the opposite of vasodilation, the widening of blood vessels. Factors causing vasoconstriction are called vasoconstrictor, also vasopressors or simply pressors. Vasoconstriction usually results in an increase of the blood pressure. Vasoconstriction may be slight or severe. Many vasoconstrictors also cause pupil dilation. Vasoconstriction in the penis can disable males from maintaining an erection (erectile dysfunction). It may result from disease, medication, or psychological conditions.

Vasoconstriction is mostly the result of increased intracellular concentration of calcium (Ca2+ions). However, specific mechanisms for generating an increased intracellular concentration of calcium depends on the vasoconstrictor. In any case, this calcium results in contraction of smooth muscle, resulting in a constriction of the vessel.