Introduction to the WFNS Grading System

The World Federation of Neurosurgical Societies (WFNS) grading system is a globally recognized framework designed to assess the severity of subarachnoid hemorrhage (SAH). Integrating the Glasgow Coma Scale (GCS), the original version of the scale delineates the clinical status of SAH patients, correlating levels of consciousness with the presence of focal neurological deficits to assign a grade ranging from I to V.

Original WFNS Grading System (o-WFNS)

In its initial form, the o-WFNS grading scale provides a five-tiered assessment based on GCS scores. The highest level of function, grade I, signifies full alertness (GCS 15), with no detectable focal neurological impairments. Conversely, grade V represents a severely compromised state (GCS 3-6), often indicating deep unconsciousness or significant neurological damage.

Distinction of Grades in o-WFNS

A crucial aspect of the o-WFNS system is distinguishing between grades II and III, based explicitly on neurological examination findings. Such evaluations can reveal critical indicators like hemiparesis or aphasia, which directly influence patient management strategies and prognosis.

Modified WFNS Grading System (m-WFNS)

To address the observed inter-rater variability and to enhance outcome prediction accuracy, the m-WFNS modifies the distinction between grades II and III by focusing solely on the GCS. This change aims to standardize assessments and provide clearer guidance for clinical decision-making and prognostication.

Clinical Significance and Application

Both the original and modified WFNS scales serve as vital tools for neurosurgeons and healthcare providers, facilitating communication, aiding in the early detection of SAH severity, and informing treatment approaches. The grading systems are particularly valuable for outlining immediate therapeutic needs and for anticipating long-term patient outcomes.