Subarachnoid hemorrhage scales

Created 25.09.2019, last update 06.10.2021

Hunt-Hess score

a graded scale used to predict the mortality rate based on the clinical features seen in a patient presenting with an aneurysmal SAH
the lower the grade, the better the prognosis
- grades I-III are associated with a favorable outcome, these patients are candidates for early surgical/endovascular treatment
- grades IV and V carry are associated with a poor prognosis; these patients require stabilization and improvement to grade III prior to surgery. Some recommend more aggressive management of patients with poor clinical grade

*Hunt-Hess grading system*
Grade	Description	Probability of severe morbidity/ mortality
0	unruptured aneurysm – incidental finding	–
1	asymptomatic mild headache and/or mild nuchal rigidity	22 %
2	lucidity cranial nerve palsies moderate to severe headache, meningeal syndrome	22 %
3	somnolence, lethargy, or confusion mild focal neurological deficits	50 %
4	stupor moderate to severe hemiparesis early decerebrate rigidity (posturing)	87 %
5	deep coma decerebrate rigidity (posturing) moribund appearance	100 %

Fisher Scale

CT findings can be quantified using the Fisher scale, which reflects the extent of SAH on the initial CT
the amount of blood in the subarachnoid space and the presence of intracerebral hematoma or hemocephalus are evaluated
the amount and distribution of blood on CT has a significant predictive value ⇒ higher Fisher grade means a worse prognosis and higher risk of vasospasms

Fisher scale
Grade	Amount of blood and its localization	vasospasm risk (%)
1	no hemorrhage detected	21
2	diffuse deposition of blood with a layer < 1 mm thick	25
3	localized clots and/or vertical layers of blood ≥ 1 mm thick	37
4	diffuse or no subarachnoid blood + intracerebral/intraventricular bleeding	31

Modified Fisher scale
Grade	Amount of blood and its localization	vasospasm risk (%)
1	SAH < 1mm	24 %
2	SAH < 1mm + intraventricular hemorrhage (IVH)	33 %
3	SAH > 1mm	33 %
4	SAH > 1mm + IVH	40 %

WFNS SAH scale

WFNS SAH scale (World Federation of Neurological Surgeons Subarachnoid Hemorrhage Scale)
grade	GCS	motor deficit, aphasia	mortality (%)
1	15	–	5
2	14-13	–	9
3	14-13	+	20
4	12-7	+/-	33
5	6-3	+/-	77