To enhance the reliability of the Circle of Willis perforation (cWp) mouse model in subarachnoid hemorrhage (SAH) research by addressing issues related to inconsistent bleeding volumes.

We introduced the ROB Scoring System, a novel protocol that integrates Rotarod Tests (RT), Open-field Tests (OT) video analysis, and daily Body Weight Loss (BWL) monitoring for precise categorization of SAH severity. Forty C57BL/6 mice underwent cWp induction and were categorized into severity subgroups (severe, moderate, mild) using the ROB system.

Validation involved comparing ROB outcomes with autopsy results on postoperative days 3 and 7 for acute and sub-acute evaluations. Mortality rates were analyzed via the survival log-rank test, revealing a significant difference among severity groups (P < 0.0001). Strong correlations between ROB grades and autopsy findings underscored its precision. The severe group exhibited 100% mortality within 4 days post-SAH onset. Individual parameters (RT, OT, BWL) were insufficient for distinguishing SAH severity levels.

The ROB Scoring System represents a significant advancement, providing a standardized protocol for precise categorization and addressing inherent bleeding variations in the cWp mouse model. This tool enhances the reliability and effectiveness of SAH research, offering valuable insights for future investigations into this critical area.