WFNS Grade Calculator (World Federation of Neurosurgical Societies SAH Scale)
Work out the WFNS grade for subarachnoid hemorrhage from the Glasgow Coma Scale and the presence of a motor deficit — grades I to V, with good-grade versus poor-grade SAH.
How it works
Grade I: GCS 15, no motor deficit · Grade II: GCS 13–14, no motor deficit · Grade III: GCS 13–14 with motor deficit · Grade IV: GCS 7–12, with or without motor deficit · Grade V: GCS 3–6, with or without motor deficit.
The World Federation of Neurosurgical Societies (WFNS) scale was proposed by a WFNS committee led by Drake and published by Teasdale and colleagues in 1988 to give subarachnoid hemorrhage a grading system based on the Glasgow Coma Scale. Level of consciousness is the strongest predictor of outcome after SAH, and a focal motor deficit matters only when the GCS is 13 or 14. Grades I–III are usually grouped as good-grade SAH and IV–V as poor-grade SAH. The grade is normally recorded after resuscitation and is repeated if the patient changes.
Worked example
A patient with subarachnoid hemorrhage opens the eyes to voice, is oriented and obeys commands (GCS 14) and has no motor deficit: WFNS Grade II — a good-grade SAH. With a hemiparesis at the same GCS the grade would be III.
Sources: Teasdale GM et al. A universal subarachnoid hemorrhage scale: report of a committee of the World Federation of Neurosurgical Societies. J Neurol Neurosurg Psychiatry 1988;51:1457 · Rosen DS, Macdonald RL. Subarachnoid hemorrhage grading scales: a systematic review. Neurocrit Care 2005
Frequently asked questions
How is the WFNS grade worked out?
From the Glasgow Coma Scale and whether there is a focal motor deficit: GCS 15 is grade I, GCS 13–14 is grade II (or III with a motor deficit), GCS 7–12 is grade IV and GCS 3–6 is grade V.
Why does the motor deficit only count at GCS 13–14?
In the committee’s analysis a focal deficit added prognostic information only for patients with a near-normal GCS; at lower GCS levels the level of consciousness dominates the outcome.
What about GCS 15 with a hemiparesis?
That combination is not defined in the original WFNS scale. It is uncommon, and clinicians usually record the GCS and the deficit separately.
Is WFNS better than Hunt and Hess?
Both predict outcome; WFNS is more reproducible between observers because it is anchored to the GCS. Many guidelines and trials report both.
Related calculators
Clinical decision tool for education and for use by trained clinicians alongside clinical judgement — not a diagnosis and not a substitute for medical assessment. Scores and cut-offs come from the cited validation studies and may not apply to every patient; follow local protocols.