ADD-ONS / SCALES

Subarachnoid hemorrhage scales

Created 25.09.2019, last update 06.10.2021

Hunt-Hess score
  • a graded scale used to predict the rate of mortality 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 favorable outcome, these patients are candidates for early surgery/endovascular treatment
    • grades IV and V carry a poor prognosis; these patients need stabilization and improvement to grade III before surgery is undertaken. Some recommend more aggressive management for patients with poor clinical grade
Hunt-Hess grading system
Grade Description
Probability of severe morbidity/ mortality
0
unruptured aneurysm – accidental finding
1
asymptomatic
mild headache and/or slight nuchal rigidity
22 %
2
lucidity
cranial nerve palsy
moderate to severe headache, meningeal syndrome
22 %
3
somnolence, lethargy, or confusion
mild focal neurological deficit
50 %
4
stupor
moderate to severe hemiparesis
early decerebrate rigidity (posture)
87 %
5
deep coma
decerebrate rigidity (posture)
moribund appearance
100 %
Fisher Scale
  • CT findings can be quantified using the Fisher scale, which reflects the extent of SAH on initial CT
  • the amount of blood in the subarachnoid space, 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 worse prognosis and higher risk of vasospasms
Fisher scale
Grade Amount of blood and its localization
vasospasms risk (%)
1
no hemorrhage detected
21
2
diffuse deposition of blood with layer < 1 mm in thickness
25
3
localized clots and/or vertical layers of blood  ≥ 1 mm in thickness
37
4
diffuse or no subarachnoid blood
+
intracerebral/intraventricular bleeding
31
Fisher scale
Modified Fisher scale
Grade
Amount of blood and its localisation
 vasospasms risk (%)
1
SAH < 1mm
24 %
2
SAH < 1mm + intraventricular hemorrhage (IVH)
33 %
3
SAH > 1mm
33 %
4
SAH > 1mm + IVH
40 %
Modified Fisher scale
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
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