Grading Scales for Subarachnoid Hemorrhage

There are numerous grading scales for subarachnoid hemorrhage (SAH) that are in use today. They attempt to subdivide patients into groups based on both clinical and radiographic findings. Some of the scales in common use include variables that account for the amount and location of hemorrhage, initial neurological status, and accompanying neurological symptoms. The value of grading scales can be assessed for their ability to predict functional outcomes, estimate surgical risk and to provide a risk assessment for the development of cerebral vasospasm. Most scales have been derived retrospectively and intra-operator variability in assigning scores is inherent in any scoring system. As more and more information is included in a grading scale, they become more difficult to use and interpret while providing only slightly increased information on outcome in comparison to some single variable systems. The review that follows provides information on the foundations of those scales in common use today and provides a suggestion on the future direction of SAH grading scales.