Comparisons between Garcia, Modo, and Longa rodent stroke scales: Optimizing resource allocation in rat models of focal middle cerebral artery occlusion

The use of rodent stroke models allow for the understanding of stroke pathophysiology. There is currently no gold standard neurological assessment to measure deficits and recovery from stroke in rodent models. Agreement on a universal preclinical stroke scale allows for comparison of the outcomes among conducted studies. The present study aimed to compare three routinely used neurological assessments in rodent studies (i.e., Garcia, Modo, and Longa) to determine which is most effective for accurately and consistently quantifying neurological deficits in the context of focal middle cerebral artery occlusion (MCAo) in rats. Focal MCAo was induced in 22 male Wistar rats using a novel transfemoral approach. Rodents were assessed for neurological deficit pre-injury as well as 3 and 24 h post-injury. Data was analyzed to determine Pearson correlation coefficients in addition to McNemar's χ2 values between each pair of neurological assessments. All three stroke scales, Garcia, Modo, and Longa, showed statistically significant changes between the baseline and the 3-hour neurological assessments. A trend towards neurological recovery was observed in all three stroke scales between the 3 and 24-hour endpoints. The three scales were highly correlated with each other, with Garcia and Modo having the strongest correlation. Of the three pairwise analyses, the comparison between the Garcia and Longa tests demonstrated the highest McNemar's χ2 value, indicating least marginal homogeneity between these two tests. The combination of high correlation between Garcia and Modo tests along with greatest marginal heterogeneity observed between the Garcia and Longa test lead us to recommend the use of Garcia and Longa neurological scales when researchers are hoping to capture the broadest range of neurological factors using only two stroke scales.