Convexity Subarachnoid Hemorrhage Soon after Starting a Direct Oral Anticoagulant in 2 Patients with Acute Infarction

Convexity subarachnoid hemorrhage (cSAH) is typically due to head trauma, but it rarely occurs subsequent to acute ischemic stroke. Direct oral anticoagulants (DOACs) have favorable bleeding profiles as compared with warfarin, and, to our knowledge, no DOAC has been regarded as a causative agent for cSAH. Here, we reported 2 patients with cSAH apparently caused by starting DOAC therapy. No hemorrhage had been evident just prior to treatment initiation, but cSAH occurred so soon after DOAC therapy began. Each of our patients had occlusion or severe stenosis of a major artery due to emboligenic disease, and cSAH occurred in the territory of the affected artery. Reperfusion and dynamic changes in perfusion pressure due may trigger cSAH. Clinicians should remain alert for cSAH when starting DOAC for treatment of embolic ischemic stroke during the acute phase.