The BNI (Barrow Neurological Institute) classification for subarachnoid hemorrhage was first described in 2012[^1] and correlates the radiographic extent of Subarachnoid hemorrhage with the risk of developing Vasospasm.
Classification
BNI grade | Maximum SAH clot thickness (mm) | Incidence of symptomatic vasospasm (%) |
BNI grade 1 | No radiographically visible SAH | 0 |
BNI grade 2 | ≤ 5 | 12,5 |
BNI grade 3 | >5 to 10 | 21,6 |
BNI grade 4 | >10 to 15 | 29,6 |
BNI grade 5 | >15 | 50 |