Vasospasm Monitored by Transcranial Doppler

Abstract

Vasospasm almost always occurs following rupture of an aneurysm in the Circle of
Willis. Spasm is less likely in peripherally located aneurysms, for example those complicating
bacterial endocarditis.
For a day or two spasm is often absent or minimal. If the patient’s condition is good,
many surgeons will proceed at this time either with surgery or endovascular placement of coils
in the aneurysm to make it undergo thrombosis.
Spasm is due to the evolution of oxyhemoglobin from hemoglobin, causing depletion
of the vasodilating nitrous oxide synthase.1 From the third day after hemorrhage onward,
with or without surgical or endovascular intervention, spasm develops progressively, generally
reaching a maximum plateau at the end of the first week. It is during the period of increasing
spasm and the early plateau period that serious ischemic complications are likely to occur.The
standard management during this time is “Triple H”: Hypertension, Hemodilution, and Hypervolemia.