Abstract Body: Objective: In clinical practice, initial neurological status such as impaired consciousness is believed to correlate with patient outcomes in subarachnoid hemorrhage (SAH). However, evaluation methods such as the modified Garcia Score (mGS) commonly used in SAH basic research are inadequate for assessing consciousness, lack quantitative measures, and are subjective. This study aimed to develop an evaluation method that overcomes these limitations.

Methods: A SAH model was created using Sprague-Dawley rats (Male, 280–320 g). The study included a SAH group (n=18) and a sham-operated group (n=4), established via the endovascular perforation method. In addition to conventional neurological assessments (mGS and beam balance test [BB]), consciousness and brainstem function were evaluated using seven parameters: respiration, whisker movement, eye blink, pinna reflex, vision, auditory response, and righting reflex. These evaluations were conducted by three independent raters. A grip strength test was also performed to quantitatively assess motor function. The primary outcome evaluation was conducted 24 hours post-SAH, followed by brain removal and analysis after euthanasia. Brain swelling was assessed by measuring brain volume, and neurodegeneration was evaluated using Fluoro-Jade C staining. Inter-rater reliability (Fleiss Kappa) was calculated for each evaluation item, and correlations with outcomes were analyzed using Pearson's correlation coefficient.

Results: Two rats in the SAH group died within 24 hours and were excluded from the analysis. The following seven parameters showed significantly high inter-rater agreement and a correlation with primary outcome: spontaneous activity, whisker movement, auditory response, righting reflex, climbing movement, forelimb movement, and BB). These seven parameters plus a grip strength test was included to develop a new scoring system (Figure), and this new method was compared with the conventional mGS method. The new assessment showed improved correlation with outcomes and reduced variability between raters’ scores.

Conclusion: The new scoring system, incorporating assessments of consciousness and quantitative motor function, provided a more accurate reflection of brain damage in SAH model rats compared to traditional methods, with improved inter-rater agreement.