How do you approach treatment and management of angiogram negative non-aneurysmal subarachnoid hemorrhage?

If DSA is negative, we will typically obtain an MRI of the brain and cervical spine to rule out unusual causes such as cervical spinal AVM/AVF that can cause SAH. If that is also negative, depending on the patient's socioeconomic factors and likelihood of follow-up, we will repeat the angiogram in 7...

We repeat the catheter-based angiogram 7-10 days after the initial angiogram negative angiogram. MRI of the brain, including the spine, if SAH is predominantly in the posterior fossa.