J Neurol Surg A Cent Eur Neurosurg 2014; 75 - p56
DOI: 10.1055/s-0034-1383785

Reconsidering the Logic of WFNS Grading in Patients with Severe Subarachnoid Hemorrhage

C. Fung 1, M. Murek 1, M. Balmer 1, J. Abu Isa 1, W. Z'Graggen 1, C. Ozdoba 2, J. Gralla 2, S. Jakob 3, J. Takala 3, J. Beck 1, A. Raabe 1
  • 1Department of Neurosurgery, University Hospital and University of Bern, Bern, Switzerland
  • 2Institute for Diagnostic and Interventional Neuroradiology, University Hospital and University of Bern, Bern, Switzerland
  • 3Department of Intensive Care Medicine, University Hospital and University of Bern, Bern, Switzerland

Aim: Current data show a favorable outcome in up to 50% of patients with World Federation of Neurosurgical Societies (WFNS) grade V subarachnoid hemorrhage (SAH) and a rather poor prediction of worst cases. Thus, the usefulness of the current WFNS grading for clinical studies and for making treatment decisions is limited. One reason for this lack of differentiation is the use of “negative” diagnostic signs as part of the WFNS grade V definition. We therefore re-evaluated the WFNS scale by using “positive” signs and the logic of the Glasgow Coma Scale (GCS) as a progressive herniation score.

Methods: We performed a retrospective analysis of 182 SAH patients with poor grade WFNS. Patients were graded according to the original WFNS scale and additionally according to a modified classification, the ‘WFNS herniation’ scale (WFNSh; grade IV, no clinical signs of herniation; grade V, clinical signs of herniation). Outcome was compared between these two grading systems.

Results: The positive predictive values (PPV) for poor outcome were 74.3% (odds ratio [OR] 3.79, 95% confidence interval [CI] = 1.94, 7.54) and 85.7% (OR 8.27, 95% CI=3.78, 19.47) for WFNS grade V and WFNSh grade V, respectively. With respect to mortality the PPVs were 68.3% (OR 3.9, 95% CI=2.01, 7.69) for WFNS grade V and 77.9% (OR 6.22, 95% CI=3.07, 13.14) for WFNSh grade V.

Conclusions: Limiting WFNSh grade V to the “positive” clinical signs of the GCS such as flexion, extension and mydriasis instead of including “no motor response” increases the prediction of mortality and poor outcome in patients with severe SAH.