The World Federation of Neurosurgical Societies (WFNS) score is a standardized classification system for individuals experiencing a subarachnoid hemorrhage (SAH). It provides a rapid and consistent method for medical professionals to evaluate neurological status upon admission. Its primary purpose is to offer a universally understood measure of severity, facilitating communication and initial assessment.
Understanding the WFNS Score
The WFNS score was developed by the World Federation of Neurosurgical Societies in 1988 to create a more objective and globally consistent system for grading the severity of aneurysmal subarachnoid hemorrhage (aSAH). Before its introduction, various grading scales existed, which sometimes led to inconsistencies in patient assessment and communication. The WFNS scale aimed to overcome these limitations.
This scoring system is applied to patients who have experienced an aSAH, a serious condition where bleeding occurs in the space surrounding the brain, often due to a ruptured aneurysm. The score helps categorize the degree of neurological impairment, ranging from mild symptoms to severe neurological deficits or coma, by evaluating specific aspects of a patient’s neurological function. This allows for a clearer understanding of their immediate condition and potential prognosis.
Components and Grading System
The WFNS score relies on two main components to determine a patient’s grade: the Glasgow Coma Scale (GCS) score and the presence or absence of focal neurological deficits, particularly motor deficits. The GCS is a widely recognized neurological assessment tool that evaluates a person’s level of consciousness based on their eye opening, verbal response, and motor response, with a total score ranging from 3 to 15. A higher GCS score indicates a better level of consciousness.
The WFNS grading system assigns a score from I to V, with higher grades indicating greater severity of neurological impairment:
Grade I: GCS 15, no motor deficit.
Grade II: GCS 13-14, no focal motor deficit.
Grade III: GCS 13-14, with focal neurological deficit (e.g., weakness on one side of the body).
Grade IV: GCS 7-12, with or without focal motor deficit.
Grade V: GCS 3-6, with or without motor deficits.
Clinical Significance and Application
The WFNS score holds importance in clinical practice for managing patients with subarachnoid hemorrhage. It plays a role in predicting patient outcomes following SAH; lower WFNS grades are associated with a more favorable prognosis, while higher grades suggest a poorer outcome. For instance, a WFNS Grade 3 at its worst pretreatment can predict a 75% favorable outcome, whereas a Grade 5 often predicts an 87% poor outcome. This predictive capability assists medical teams in counseling families and planning long-term care.
The score also directly influences treatment decisions, guiding medical professionals on the timing and aggressiveness of interventions such as surgical clipping or endovascular coiling of the ruptured aneurysm. Patients with lower WFNS grades may be candidates for earlier intervention, while those with higher grades might require initial stabilization before definitive treatment.
The WFNS score facilitates clear and efficient communication among healthcare providers globally. By providing a standardized language to describe a patient’s neurological status, it ensures that all members of the medical team, regardless of their location, understand the severity of the patient’s condition. This consistency is valuable in multidisciplinary settings and for transferring patients between facilities. The score is also used in research studies to categorize patient cohorts, allowing for more uniform data collection and analysis of treatment effectiveness and outcomes across different studies.