Modified Glasgow coma scale for predicting outcome after subarachnoid hemorrhage surgery

There are many grading scales that attempt to predict outcome following aneurysmal subarachnoid hemorrhage (aSAH). Most scales used to assess outcome are based on the neurological status of the patient. Here, we propose a new scale for aSAH patients that combines the Glasgow Coma Scale (GCS) and the modified Fisher scale (mFS). Five hundred ninety-seven patients with aSAH who were treated at our institution between January 2008 and December 2017 were retrospectively analyzed. Initial GCS score, Hunt and Hess scale, World Federation of Neurosurgical Societies scale, mFS, and modified Rankin Scale were obtained by reviewing data. Incidence of vasospasm was investigated. Factors found to be significant on a multivariable regression analysis were used to develop a scale that was compared with other grading systems using the area under the curve (AUC) calculated from receiver operating characteristic curve. The GCS score and mFS were related to outcomes in patients with aSAH. A simple score, which we call the GCS-F score, was calculated using these initial data. The GCS-F score had an AUC of 90.5% for unfavorable outcome prediction, and 88.4% for in-hospital mortality prediction. On the receiver operating characteristic curve analysis for vasospasm, the AUC for World Federation of Neurosurgical Societies, mFS and GCS-F scores were 0.912, 0.704, and 0.936, respectively. A simple arithmetic combination of the GCS score and mFS, the GCS-F score, includes the radiographic status as well as the clinical status of the patient, so that the state of the patient can be known in more detail than other single scales. The GCS-F score may be a useful scale for predicting outcome and the occurrence of vasospasm in patients with aSAH.