Acute Ischemic Stroke in 2026: From Time to Penumbra-An Updated Narrative Review of Reperfusion Strategies with a Latin American Implementation Perspective.

Background/Objective: The management of acute ischemic stroke (AIS) has evolved from rigid time-based treatment paradigms toward tissue-based selection guided by advanced neuroimaging, thereby expanding eligibility for reperfusion therapies. To provide an updated narrative review of acute ischemic stroke (AIS) classification and management, with emphasis on extended therapeutic windows for intravenous thrombolysis (IVT) and endovascular therapy (EVT), bridging strategies, posterior circulation stroke, and implementation challenges in Latin America and other resource-constrained settings. Methods: A structured narrative review was conducted using the PubMed/MEDLINE, Embase, Scopus, and LILACS databases, covering the period from 2013 to 2025. Results: Sixty-three studies were selected from 412 records and categorized into etiologic classification, extended-window thrombolysis, EVT and bridging therapy, and posterior circulation stroke. Current evidence supports imaging-guided IVT beyond 4.5 h and EVT up to 24 h in selected patients with salvageable brain tissue, including some individuals with large infarct cores. Recent trials also support EVT for basilar artery occlusion. Tenecteplase offers practical workflow advantages in many centers, particularly where transfer delays and limited access to advanced imaging constrain timely reperfusion decisions. Conclusions: Contemporary AIS management is increasingly guided by pathophysiology and imaging rather than strict time thresholds. However, improving outcomes in middle- and low-income settings requires the implementation of adapted clinical algorithms, strengthening of stroke care networks, and optimization of referral pathways.