NPY and brain ischemia: When evaluating the potential pathophysiological role of vasoactive endogenous neuropeptides in sSAH-related cerebral hemodynamic changes, CV-induced cerebral ischemia, and outcome after sSAH, neuropeptide Y (NPY) [24–27] and calcitonin gene-related peptide (CGRP) [28–33] have gained paramount interest.