Figure 6.

Changes in brain perfusion of the most severe vasospasm case, beginning with the unremarkable status after intervention (upper row), followed by the status when presenting with global aphasia and severe, unilateral headache (middle row, three weeks later), and after a week of mean arterial pressure-driven i.a. anti-vasospastic treatment (inferior row). Upper row—initial status: conventional p.a. angiogram of the right ICA, left ICA, and DSA perfusion prior to FDS implantation: functionally autonomic supply of both hemispheres via each ipsilateral ICA. Middle row—acute-phase vasospasm: significant collateral supply from the right ICA via the AcomA along left A1 for compensation of acute-onset, hemodynamically critical vasospastic stenosis. Note the severely reduced left-sided cerebral blood volume represented by area under the curve perfusion image. Inferior row—equilibrated collateral flow and increase in left-sided brain perfusion after multiple intra-arterial treatments for segmental vasospasm. Eventually, the left and right ACA territory is supplied from the right ICA. Left MCA perfusion is sufficient via the left ICA.