Comparative Analysis of Cerebral Infarct Size and Neuronal Viability in Permanent versus Transient Middle Cerebral Artery Occlusion Models

Ischemic stroke represents the majority of cerebrovascular disease, with large vessel occlusion (LVO) involving the middle cerebral artery (MCA) in nearly 80% of cases. The MCA occlusion (MCAO) model is central to experimental stroke research, yet most studies focus on transient MCAO (tMCAO), which reflects reperfused stroke and dominates 88% of publications. In contrast, permanent MCAO (pMCAO) better models non‑reperfused LVO but remains underexplored, often compared only with sham or limited to short observation periods. This gap underscores the need for systematic evaluation of both models across extended durations. Thirty male Sprague-Dawley rats were divided into five groups: sham, tMCAO, and pMCAO at 6, 18, and 24 hours. Results indicated that pMCAO produced significantly larger infarcts and greater neuronal loss than tMCAO, with infarct size increasing progressively to 12.84% at 24 hours and neuronal viability declining from 60% at 6 hours to 19% at 24 hours. In contrast, tMCAO resulted in smaller infarcts (4.70%) and greater neuronal preservation (67%). This study demonstrates that 24 hours post-occlusion is the most meaningful timepoint for pMCAO, as infarct volume reaches maximal extent and neuronal viability shows the greatest decline.