Best Motor Response Predicts Favorable Outcome for “True” WFNS Grade V Patients with Aneurysmal Subarachnoid Hemorrhage

Highlights

• Recent studies showed effectiveness of ultra-early (<24 H) aneurysm repair strategy.

• Its universal application for severe SAH patients may increase futile intervention.

• No guideline exists for WFNS grade V patients after initial supportive therapy.

• Factors for favorable treatment outcome in “true grade V SAH” patients were studied.

• Best motor response rated as 4 was a good clinical indicator in this cohort.

• This simple index may optimize aggressive treatment strategy for severe SAH cases.

Abstract

Background

The universal application of ultra-early surgery for World Federation of Neurological Societies (WFNS) grade V aneurysmal subarachnoid hemorrhage (aSAH) patients may lead to the increased implementation of unnecessary treatment. Therefore, this study aimed to refine the patient selection process for timely definitive treatment.

Methods

From January 2011 to March 2020, a total of 517 aSAH patients were treated at our institution. Among these, 177 aSAH patients with WFNS grade V on admission were identified from our database. Patients with improved grades in response to the initial supportive treatment, with clinical or radiological signs of herniation, and with irreversible signs of brain damage such as bilaterally dilated pupils and global ischemia on follow-up CT scan were excluded. The outcome of definitive treatment for 54 patients without herniation who remained with WFNS grade V after the initial supportive treatment were analyzed to seek any factor for a favorable outcome (modified Rankin scale 0–2).

Results

Among 54 patients, 19 (35.2%) had a favorable outcome after a definitive treatment. Multivariate logistic regression analysis showed that the best motor response (BMR) 4 on Glasgow Coma Scale was significantly associated with favorable outcomes (odds ratio, 3.76; 95% confidence interval, 1.09–13.0, p = 0.03). The positive predictive value of BMR 4 was 48.3%.

Conclusions

Albeit being simple, BMR 4 may facilitate the prompt aggressive treatment for patients with WFNS grade V including those with “true” grade V who do not have any clinical and radiological signs of herniation.

Introduction

Preoperative neurological assessment provides critical information on the treatment for aneurysmal subarachnoid hemorrhage (aSAH) to predict the outcome and determine the surgical indication.1, 2, 3, 4, 5 Therefore, numerical scoring methods such as the Hunt & Hess scale,² Hunt and Kosnik scale,¹ and World Federation of Neurosurgical Societies (WFNS) scale⁶ have been proposed and established to describe temporary changes and estimate prognosis in an individual patient and to compare the management outcome in different patient groups.⁵ Although minor differences exist between scales, the worst grade is commonly defined as grade V characterized by a deep comatose status. The prognosis of patients classified as grade V is considered as generally poor: nearly all patients eventually die without definitive treatment for ruptured aneurysms.^7,8 However, recent studies have shown that 14–41% of patients with WFNS grade V have favorable outcome after the definitive treatment,9, 10, 11, 12 indicating the heterogeneous nature of the cohort.

The mechanism of coma in patients with aSAH is multifactorial. While some patients may have irreversible brain damage, such as whole brain hypoxic injury or massive hematoma, others may have temporarily disturbed consciousness because of increased intracranial pressure, hydrocephalus, and epilepsy.^7,13,14 These reversible conditions do not preclude the necessity of aggressive treatment. By contrast, the appropriate and timely assessment of brain dysfunction during emergency treatment is difficult, particularly for comatose patients because of the frequent need for intubation and sedation to stabilize their vital signs. Recent data showed that the ultra-early aneurysm repair strategy (<24 h from the onset) is associated with better treatment outcome for patients with aSAH.15, 16, 17, 18 Although immediate intervention is critical to prevent rebleeding, universal application of aggressive treatment for patients with the poorest grade without excluding those with irreversible damage would lead to increased futile intervention. Currently, the guideline to settle this clinical dilemma for the treatment of patients with WFNS grade V is not yet established.

In our institution, we have prioritized the initial supportive treatment such as ventricular drainage and hyperosmolar therapy over the definitive treatment for patients with WFNS grade V unless they have clinical or radiological signs of herniation. Consequently, we have had the opportunity to treat patients who remain in WFNS grade V after the initial supportive treatment. In this study, we call them patients with “true” WFNS grade V for a descriptive purpose. We reviewed our treatment outcomes in these patients and investigated whether any predictive factor exists for favorable outcomes to refine the treatment strategy for patients with the poorest grade aSAH.