Grade I:
GCS of 15, with no motor deficit.

Grade II:
GCS of 13–14, with no motor deficit.

Grade III:
GCS of 13–14, with a focal neurological deficit.

Grade IV:
GCS of 7–12, with or without a deficit.

Grade V:
GCS of <7, with or without a deficit. 

Note:
The modified WFNS scale (mWFNS) simplifies this by assigning Grade II based purely on GCS 14 and Grade III purely on GCS 13, without checking for a deficit

Information

The WFNS score is a 5-grade scale that assesses the severity of a subarachnoid hemorrhage (SAH) based on the patient’s Glasgow Coma Scale (GCS) score and whether they have a focal neurological deficit. A lower WFNS score indicates a better prognosis, with Grade 1 being the most favorable and Grade 5 the most severe.