vasospasm

Vasospasm is the narrowing of a blood vessel caused by contraction of vascular smooth muscle, resulting in reduced blood flow to the supplied tissue. It can affect cerebral, coronary, or peripheral arteries and may occur in the setting of injury, hemorrhage, or autonomic dysregulation, as well as in primary vascular disorders.

Cerebral vasospasm is a well-recognized complication after aneurysmal subarachnoid hemorrhage and, less commonly, after other brain injuries. It typically develops several days after the initial hemorrhage, often peaking around days 5 to 7, and can lead to delayed cerebral ischemia. Pathophysiology involves blood breakdown products, inflammation, endothelial dysfunction, and imbalances in vasodilators and vasoconstrictors such as reduced nitric oxide and increased endothelin. Diagnosis relies on clinical change plus imaging or physiologic evidence of arterial narrowing. Transcranial Doppler ultrasound shows increased flow velocity in affected vessels; CT angiography or MR angiography can confirm narrowing, and diagnostic angiography may be used for therapeutic decisions. Management emphasizes prevention and treatment of vasospasm and maintenance of cerebral perfusion; nimodipine, a calcium channel blocker, improves outcomes after aneurysmal SAH. Euvolemia with careful hemodynamic management is preferred over aggressive hypervolemia; induced hypertension may be used to augment cerebral perfusion in selected patients. Refractory vasospasm can be treated with intra-arterial vasodilators or mechanical angioplasty.

Coronary vasospasm, or Prinzmetal’s angina, involves transient constriction of coronary arteries, causing chest pain and sometimes transient ST-segment changes. Triggers include smoking and cocaine; therapy centers on calcium channel blockers and short-acting nitrates, with avoidance of provoking substances.

Peripheral vasospasm affects limbs and may be seen in conditions such as Raynaud’s phenomenon, where digital arteries constrict in response to cold or stress; treatment focuses on triggers, vasodilator medications, and lifestyle modification.