Herniation World Federation of Neurosurgical Societies Scale Improves Prediction of Outcome in Patients With Poor-Grade Aneurysmal Subarachnoid Hemorrhage

Abstract

BACKGROUND: Favorable outcomes are seen in up to 50% of patients with World Federation of Neurosurgical Societies (WFNS) grade V aneurysmal subarachnoid hemorrhage. Therefore, the usefulness of the current WFNS grading system for identifying the worst scenarios for clinical studies and for making treatment decisions is limited. We previously modified the WFNS scale by requiring positive signs of brain stem dysfunction to assign grade V. This study aimed to validate the new herniation WFNS grading system in an independent prospective cohort. METHODS: We conducted an international prospective multicentre study in poor-grade aneurysmal subarachnoid hemorrhage patients comparing the WFNS classification with a modified version—the herniation WFNS scale (hWFNS). Here, only patients who showed positive signs of brain stem dysfunction (posturing, anisocoric, or bilateral dilated pupils) were assigned hWFNS grade V. Outcome was assessed by modified Rankin Scale score 6 months after hemorrhage. The primary end point was the difference in specificity of the WFNS and hWFNS grading with respect to poor outcomes (modified Rankin Scale score 4–6). RESULTS: Of the 250 patients included, 237 reached the primary end point. Comparing the WFNS and hWFNS scale after neurological resuscitation, the specificity to predict poor outcome increased from 0.19 (WFNS) to 0.93 (hWFNS) (McNemar, P <0.001) whereas the sensitivity decreased from 0.88 to 0.37 ( P <0.001), and the positive predictive value from 61.9 to 88.3 (weighted generalized score statistic, P <0.001). For mortality, the specificity increased from 0.19 to 0.93 (McNemar, P <0.001), and the positive predictive value from 52.5 to 86.7 (weighted generalized score statistic, P <0.001). CONCLUSIONS: The identification of objective positive signs of brain stem dysfunction significantly improves the specificity and positive predictive value with respect to poor outcome in grade V patients. Therefore, a simple modification—presence of brain stem signs is required for grade V—should be added to the WFNS classification. REGISTRATION: URL: https://clinicaltrials.gov; Unique identifier: NCT02304328.

Significance of Pupillary Findings in Decision Making and Outcomes of World Federation of Neurological Societies Grade V Subarachnoid Hemorrhage

“…They validated that the hWFNS scale had a better overall diagnostic quality concerning poor outcomes. 14,25 The full outline of unresponsiveness score, which includes the assessment of brainstem reflexes and respiration in addition to eye and motor response, has advantages in assessing comatose patients under intubation. 26…”

Quality of Life After Poor-Grade Aneurysmal Subarachnoid Hemorrhage

“…Further details on study design, clinical management, and primary end point results are published elsewhere. 11…”

“…Treatment was according to current guidelines and included immediate neurological resuscitation (external cerebrospinal fluid drainage in case of hydrocephalus, seizure treatment, and general intensive care measures), early angiography, and transfer to an intensive care unit. [11][12][13] Clinical status after neurological resuscitation was used for WFNS grading. Further details on study design, clinical management, and primary end point results are published elsewhere.…”

“…3-10 Here, we present novel prospective data on QoL in survivors of poor-grade aSAH from the herniation World Federation of Neurosurgical Societies (WFNS) scale study. 11…”

“…Further details on study design, clinical management, and primary end point results are published elsewhere. 11 Data on QoL, disability outcome, and home status were collected 6 and 12 months after ictus during a structured telephone interview conducted by an independent trained investigator or study nurses blinded to the clinical course. QoL was measured using the EuroQoL -5 Dimensions -3 Levels (EQ-5D-3L) questionnaire, reporting health profiles in 5 dimensions (mobility, self-care, usual activities, pain and discomfort, anxiety, and depression), each of which has 3 response levels (no problems, some problems, and extreme problems).…”