Hemorrhagic Stroke Severity Grading Scales
For subarachnoid hemorrhage, use the Hunt and Hess (HH) grade or World Federation of Neurosurgical Societies (WFNS) grade to determine initial clinical severity and predict outcome, as recommended by the 2023 AHA/ASA guidelines. 1
Subarachnoid Hemorrhage (SAH) Grading Systems
Primary Clinical Scales
- Hunt and Hess (HH) Grade and WFNS Grade are the two recommended clinical scales for SAH severity assessment and outcome prediction 1
- Both scales effectively stratify patients into high-grade (HH 4-5 or WFNS 4-5) versus lower-grade categories, which directly impacts treatment decisions 1
- The Glasgow Coma Scale (GCS) can also be compressed into five grades comparable to HH and WFNS, with equal or greater predictive value for outcome and superior interrater reliability (kappa 0.46 vs 0.41 for HH and 0.27 for WFNS) 2
Composite and Radiographic Scales
- Fisher Scale is used to grade the amount of blood on CT imaging 3
- Newer composite scores combine clinical and radiographic features, including VASOGRADE, HAIR (HH grade, age, intraventricular hemorrhage, rebleed), SAHIT (Subarachnoid Hemorrhage International Trialists), and SAH scores 1
- These composite scales provide enhanced clinical outcome prediction but add complexity that may limit routine adoption 3
Clinical Application Considerations
- High-grade SAH (HH 4-5 or WFNS 4-5) patients can achieve favorable outcomes in approximately 39-40% of cases when treated, justifying aneurysm repair unless irrecoverable brain injury is present 1
- For standardized reporting, publications should document at minimum the admission GCS plus prognostic factors: age, pre-existing hypertension, blood volume on CT, time from SAH to admission, aneurysm characteristics, presence of intracerebral/intraventricular hemorrhage, and admission blood pressure 3
Intracerebral Hemorrhage (ICH) Grading Systems
ICH Score
- The ICH Score is the current standard prognostic scale for spontaneous intracerebral hemorrhage 4
- It demonstrates strong correlation with 90-day modified Rankin Scale (mRS) outcomes (r = 0.62) and accurately predicts both dependency/death (c-statistic = 0.80) and case fatality (c-statistic = 0.80) 4
NIHSS for ICH
- The National Institutes of Health Stroke Scale (NIHSS) performs comparably to the ICH Score for predicting 3-month outcomes in ICH patients 4
- NIHSS predicts dependency or death with 74.1% accuracy (threshold NIHSS ≥17.5) and case fatality with 75.0% accuracy (threshold NIHSS ≥18.5) 4
- A major advantage of NIHSS is its widespread documentation in routine clinical care and administrative datasets, enabling harmonized assessment across both ischemic and hemorrhagic stroke 4
- NIHSS substantially improves predictive accuracy when incorporated into risk models (c-statistic 0.86 with NIHSS vs 0.78 without) and performs nearly equally well across all stroke types 5
Practical Implementation
- Both ICH Score and NIHSS are strongly correlated with each other (r = 0.73) and with 90-day functional outcomes 4
- The NIHSS offers practical advantages for quality monitoring, case-mix risk adjustment, and therapy development because it is already routinely collected 4
- For ICH specifically, strict blood pressure control (<130/80 mmHg) at follow-up visits is essential to minimize hematoma expansion and recurrence risk 6