Vasospasm refers to a condition in which an arterial spasm leads to vasoconstriction. This can lead to tissue ischemia and tissue 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 especially after aneurysmal subarachnoid hemorrhage. Vasospasm typically appears 4 to 10 days after subarachnoid hemorrhage. Along with physical resistance, vasospasm is a main cause of ischemia. Like physical resistance, vasospasms can occur due to atherosclerosis. Vasospasm is the major cause of Prinzmetals angina. Pathophysiology
Normally endothelial cells release prostacyclin and nitric oxide (NO) which induce relaxation of the smooth muscle cells, and reduce aggregation of platelets. Aggregating platelets stimulate ADP to act on endothelial cells and help them induce relaxation of the smooth muscle cells. However, aggregating platelets also stimulate thromboxane A2 and serotonin which can induce contraction of the smooth muscle cells. In general, the relaxations outweighs the contractions. In atherosclerosis, a dysfunctional endothelium is observed on examination. It does not stimulate as much prostacyclin and NO to induce relaxation on smooth muscle cells. Also there is not as much inhibition of aggregation of platelets. In this case, the greater aggregation of platelets produce ADP, serotonin, and thromboxane A2. However the serotonin and the thromboxane A2 cause more contraction of the smooth muscle cells and as a result contractions outweigh the relaxations. Complications
Vasospasm can occur in a wide variety of peripheral vascular beds under poorly understood mechanisms.
Signs and symptoms
Academic setting
As with other anxiety disorders, children with SAD tend to face more obstacles at school than those without anxiety disorders. Adjustment and relating school functioning have been found to be much more difficult for anxious children. In some severe forms of SAD, children may act disruptively in class or may refuse to attend school altogether. It is estimated that nearly 75% of children with SAD exhibit some form of school refusal behavior.There are several possible manifestations of this disorder when the child is introduced into an academic setting. A child with SAD may protest profusely upon arrival at school. They might have a hard time saying goodbye to their parents and exhibit behaviors like tightly clinging to the parent in a way that makes it nearly impossible for the parent to detach from them. They might scream and cry but in a way that makes it seem as though they were in pain. The child might scream and cry for an extended period of time after his or her parents are gone (for several minutes to upwards of an hour) and refuse to interact with other children or teachers, rejecting their attention. They might feel an overwhelming need to know where their parents are and that they are okay.