🧠 Modified Fisher Scale (SAH Vasospasm Risk)
Estimate cerebral vasospasm risk after SAH with the modified Fisher scale.
Modified Fisher Scale (SAH Vasospasm Risk)
CT appearance
When to use
Predict symptomatic vasospasm from the CT bleed pattern.
How it works
Grades 0–4 based on thickness of subarachnoid blood and presence of intraventricular haemorrhage. Higher grades carry higher vasospasm risk.
Key points
- Thick cisternal blood plus IVH carries the highest risk.
- Guides intensity of vasospasm surveillance.
- Complements clinical grading scales.
References
Decision support for licensed clinicians only; not a substitute for clinical judgement, diagnosis or local protocols.