Occlusion of all cardinal cerebropetal arteries without causing ischemic stroke

A 66-year-old male presented with a sudden severe headache, transient loss of consciousness and persisting vertigo. A subarachnoid hemorrhage was detected via lumbar puncture. The CT scan was negative and an MRI detected a few T2 hyperintense foci of ischemic origin and the suspected subarachnoid hemorrhage. An MRA revealed occlusions of all four magistral cerebral arteries and the presence of an excessively developed collateral circulation, later proven with DSA. The patient did not suffer from focal ischemia despite this severe cerebrovascular disease. At the time of discharge after 30 days of hospitalization, previous mild meningeal signs, cephalea and vertigo were no longer present.