Grading system for Subarachnoid Hemorrhage.
The clinical condition of the patient on admission as assessed using the World Federation of Neurosurgical Societies (WFNS) grading scale is currently considered the gold standard. However, the timing of the clinical assessment is subject to debate, as is the contribution of additional predictors.
GCS 15 Motor deficit absent
GCS 13 - 14 Motor deficit absent
GCS 13 - 14 Motor deficit present
GCS 7 - 12 Motor deficit present or absent
GCS 3-6 Motor deficit present or absent
The clinical grading system proposed by the World Federation of Neurologic Surgeons is intended to be a simple, reliable and clinically valid way to grade a patient with subarachnoid hemorrhage. This system offers less interobserver variability than some of the earlier classification systems.
*Where a motor deficit refers to a major focal deficit.
Interpretation: • Maximum score of 15 has the best prognosis
• Minimum score of 3 has the worst prognosis
• Scores of 8 or above have a good chance for recovery
• Scores of 3-5 are potentially fatal, especially if accompanied by fixed pupils or absent oculovestibular responses
• Young children may be nonverbal, requiring a modification of the coma scale for evaluation
Aneurysmal subarachnoid hemorrhage (aSAH) is associated with high rates of mortality and morbidity. The main predictor for the poor outcome is the World Federation of Neurosurgical Societies (WFNS) scale. However, this scale does not take into account proinflammatory events, such as infection occurring after the aSAH, which could modify the long-term status of patients 1).
The aim of a study was to identify either the conventional WFNS grade on admission or the WFNS grade after neurological resuscitation (rWFNS) as the most accurate predictor of outcome after SAH.
This prospective observational cohort study included 1620 consecutive patients with SAH admitted between January 1998 and December 2014 at our university neurovascular center. The primary outcome measure was a poor modified Rankin Scale score at the 2-month follow-up. Clinical predictors were identified using multivariate logistic regression analyses. Area under the receiver operating characteristic curve (AUC) analysis was used to test discriminative performance of the final model. An AUC of > 0.8 was regarded as indicative of a model with good prognostic value. RESULTS Poor outcome (modified Rankin Scale Score 4-6) was observed in 25% of the patients. The rWFNS grade was a significantly stronger predictor of outcome than the admission WFNS grade. The rWFNS grade was significantly associated with poor outcome (p < 0.001) as well as increasing age (p < 0.001), higher modified Fisher grade (p < 0.001), larger aneurysm size (p < 0.001), and the presence of an intracerebral hematoma (OR 1.8, 95% CI 1.2-2.8; p = 0.002). The final model had an AUC of 0.87 (95% CI 0.85-0.89), which indicates excellent prognostic value regarding the discrimination between poor and good outcome after SAH.
In clinical practice and future research, neurological assessment and grading of patients should be performed using the rWFNS to obtain the best representation of their clinical condition 2).