Pathophysiology and prognosis of patients with ruptured intracranial aneurysm

Changes of cerebral blood flow (CBF), low perfusion areas (LPA) and redistribution phenomenon (RD), in which operations were performed within 24 hours after the onset of SAH, were examined using N-isopropyl-p-[123I] iodoamphetamine (IMP) SPECT in 16 cases. CBF patterns changed remarkably during the acute, subacute and chronic stages. In the acute stage, CBF of the affected side decreased due to vasospasm and operative procedures, and large LPAs were seen in many cases. However, good RD was recognized in most cases. In the subacute stage, CBF of the affected side increased and LPA decreased in size and number. In the chronic stage, CBF of the affected side decreased again, and in some cases transhemispheric diaschisis was seen. In eight cases the absolute values of CBF were also measured. These values showed almost the same changes described above in each stage. Cases with remarkably low CBF and large LPA without RD in the acute stage showed poor prognosis. (author)