Aneurysmal Subarachnoid Hemorrhage Grading in Animal Models - Animal Models of Acute Neurological Injuries: Injury and Mechanistic Assessments - page 309

4. The animals received a total score ranging from 0 to18 after
adding the scores from all six segments (Fig. 3 ).
(a) Based on the fi nal score the animals are divided into three
groups:
(b) Grade 0-7: mild SAH
(c) Grade 8-12: moderate SAH
(d) Grade 13-18: severe SAH

4. Outcome
Measures that
Have Proven to
Correlate with this
Scale

Previous work by Sugawara et al. has statistically validated this scale
against a number of outcome measures.

4.1. Neurological
Function

1. There is a correlation between the SAH grade and neurologi-
cal score (Fig. 4 ).

4.2. Vasospasm

There is a strong correlation between the SAH grade and cerebral
vasospasm in the rodent model of endovascular perforation model
of SAH. Methods of quantifying vasospasm are provided in other
section of this topic. Below are data showing the correlations
between intracranial IC diameter, perimeter, and wall thickness,
which are commonly used histological measurement used to
quantify cerebral vasospasm in rodents (Fig. 5 ).

4.3. Interobserver
Reproducibility

This SAH grading system is consistent and correlates well between
two different blinded investigators (Fig. 6 ).

Fig. 4. Simple regression analysis and Spearman's correlation coeffi cient by rank test was
performed by Sugawara et al. and found signifi cant correlation between the SAH grade
neurological score when using a modifi ed Garcia neurological scale ( r = 0.42, p < 0.01)
( 11, 12 ). Figure adopted with modifi cation from Sugawara et al. ( 11 ) .