Mild Acute Ischemic Stroke With Large Vessel Occlusion (MISTWAVE)

Stroke remains the leading cause of disability in the United States. An estimated 40-50% of all ischemic strokes are caused by large-vessel occlusion of a major cerebral artery (LVO). However, in some cases, the occlusion results in mild symptoms, at least initially, and these patients frequently do not receive any treatment. These strokes, however, may result in unfavorable long-term outcomes despite relatively benign initial course. Recent large randomized studies in patients with severe stroke symptoms and associated LVO showed efficacy and safety of endovascular mechanical thrombectomy, but patients with mild symptoms were not specifically addressed. Based on the investigators' own data and limited evidence in the literature, the investigators propose that early mechanical thrombectomy in patients with LVO associated with mild stroke symptoms (defined as NIHSS ≤ 5) is safe, and results in favorable long-term patient outcomes. The objective of this prospective pilot study is to assess the safety and outcomes of mechanical thrombectomy in patients presenting with acute ischemic stroke due to a large vessel occlusion in the anterior or posterior circulation under 24 hours with mild symptoms (NIHSS ≤ 5).