The Role of Deep Cerebral Vein Variation in Patients With Angiographic Negative Subarachnoid Hemorrhage

Exclusion Criteria

• •1. In patients with aneurysms, external ventricular drainage (EVD) alone or decompression craniotomy alone or conservative treatment was performed
• •2. Have a history of trauma or prior brain injury (stroke, cerebral hemorrhage, etc., with associated chronic changes on CT)
• •3. Patients with loss of imaging data and severe comorditions prior to onset of SAH