| Grade | Neurologic status |
| 1 | Asymptomatic or mild headache and slight nuchal rigidity |
| 2 | Severe headache, stiff neck, no neurologic deficit except cranial nerve palsy |
| 3 | Drowsy or confused, mild focal neurologic deficit |
| 4 | Stuporous, moderate or severe hemiparesis |
| 5 | Coma, decerebrate posturing |
