Inclusion Criteria:

1. Participant age ≥ 18
2. Participant experiencing acute ischemic stroke due to a confirmed primary M2 occlusion in the vertical segment or post-bifurcation in the non-dominant or co-dominant branch of the horizontal segment
3. NIHSS ≥5 or NIHSS 3-4 with disabling symptoms
4. Pre-stroke mRS 0-1
5. For participants undergoing thrombectomy: Planned first-line treatment with Penumbra System reperfusion catheters
6. Informed consent obtained per Institutional Review Board/Ethics Committee requirements

Exclusion Criteria:

1. Any stenosis or occlusion in the ICA origin requiring treatment during the procedure or within the 90-day follow-up period.
2. Known multiple occlusions
3. Secondary M2 occlusion
4. Known or high suspicion of underlying ICAD as the cause of the M2 occlusion
5. Current hospitalization at time of stroke onset and/or any comorbid disease or condition expected to compromise survival or ability to complete follow-up assessments through 90 days
6. Currently participating in an investigational (drug, device, etc.) clinical trial that will influence the endovascular procedure or acute treatment. Participants in secondary prevention, observational, natural history and/or epidemiological studies are eligible.
7. Other medical, behavioral, or psychological conditions that in the opinion of the Investigator could limit the ability to participate in the study, including compliance with follow-up requirements, or that could impact the scientific integrity of the study