SEGA is a multicenter, randomized, comparative effectiveness trial with un-blinded caregivers but blinded assessors, in acute ischemic stroke patients with proximal intracranial arterial occlusions treated with endovascular therapy within 16 hours of symptom onset. Patients must not require intubation for any clinical indication. Arterial occlusion must be demonstrated by either CT angiogram (CTA) or MR-angiogram (MRA). Two hundred sixty subjects will be recruited over up to 15 sites and followed for 90 days for the primary efficacy outcome to estimate overall treatment benefit (improvement in disability) among acute ischemic stroke patients that are randomized to GA compared with CS during endovascular therapy.