What Fisher grade predicts highest vasospasm risk?

Modified Fisher grade 3 (thick SAH + IVH) has highest vasospasm risk (~40%). Grade 4 also high risk. Grade 0-1 have lowest risk.

When does vasospasm occur after SAH?

Vasospasm typically begins 3-5 days after SAH, peaks at 7-10 days, and resolves by day 21.

Nimodipine 60mg every 4 hours for 21 days is the standard prophylaxis — it reduces vasospasm-related deficits.

Calculate modified Fisher grade (0-4) from CT findings to predict vasospasm risk after subarachnoid hemorrhage.

Use the full interactive calculator below, or

Hunt-Hess Grade

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WFNS SAH Grade

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GCS Calculator

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NIHSS Calculator

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