SESSION TITLE: Fellows Critical Care Posters SESSION TYPE: Fellow Case Report Posters PRESENTED ON: October 18-21, 2020 INTRODUCTION: Subarachnoid hemorrhages (SAH) affect roughly 1 in 10,000 adults annually, with roughly 50% resulting in death soon after development. The majority of the cases are the result of an aneurysm rupture but rarely, can be caused by arteriovenous malformations (AVM’s). The leading cause of morbidity after surviving an SAH is the neurologic deterioration that occurs from delayed cerebral ischemia (DCI) and infarction as a result of vasospasm. AVM’s have only recently been gaining recognition as a cause of clinical deterioration from DCI’s. CASE PRESENTATION: Patient is a 41 yo female with no past medical history who initially presented with complaints of the worst headache of her life. Imaging revealed intraventricular hemorrhage (IVH) with subarachnoid hemorrhage, attributed to a ruptured AVM. CT angiogram showed a left parietal occipital AVM with associated intra-nidal aneurysms. Patient underwent embolization of the AVM and nidal aneurysms. Due to the morphology of the AVM, patient underwent a debulking and resection of the AVM with evacuation of the left IVH. Post-operative course was complicated by acute neurological change (unresponsive, minimal extremity motor exam). Imaging showed new changes consistent with an acute infarct and bilateral narrowing of the anterior and middle cerebral arteries, secondary to vasospasm. She subsequently required multiple intra-arterial treatments with verapamil. Her neurological exam slightly improved with treatments and was subsequently discharged to a long-term acute care facility for therapy. DISCUSSION: Unlike aneurysm rupture, cerebral vasospasm after a ruptured AVM is rarely reported and often not recognized as a cause of delayed cerebral ischemia. This could lead to clinical decline and should be considered in the differentials of neurological deterioration following the hemorrhage of an AVM. A recent retrospective analysis revealed that the SAH component and infratentorial location of a rupture AVM may have a higher risk for cerebral vasospasms and recommended follow-up angiographic imaging in patients with neurological deterioration. However, there currently is no recommendation for empiric delayed angiography to assess for vasospasms after a ruptured AVM. CONCLUSIONS: Despite the robust evidence-based guidelines on the comprehensive management of SAH from aneurysm ruptures, including the management of cerebral vasospasm and DCI, there is no such guideline for ruptured AVM’s. In the setting of acute neurological deterioration after treatment of an AVM (via resection or embolization), assessment for cerebral vasospasm and DCI should be considered. Reference #1: Goss BA, Du R. Vasospasm after arteriovenous malformation rupture. World Neurosurg. ;Sep-Oct;78(3-4):300-5. doi: 10.1016/j.wneu.2011.12.090. Epub 2011 Dec 28. Reference #2: Dinc N, Won Sy, Eibach M. et al. Cerebral vasospasm due to arteriovenous malformation-associated hemorrhage: Impact of bleeding source and pattern. Cerebrovasc Dis. 2019; 47(3-4):165-170. doi: 10.1159/000500596. Reference #3: Pluta RM, Hansen-Schwartz J, Dreier J, et al. Cerebral vasospasm following subarachnoid hemorrhage: time for a new world of thought. Neurol Res. 2009;31(2):151–158. doi:10.1179/174313209X393564 DISCLOSURES: No relevant relationships by Hammad Arshad, source=Web Response Scientific Medical Advisor relationship with ischemaview Please note: $1-$1000 Added 05/01/2020 by Russell cerejo, source=Web Response, value=Travel No relevant relationships by Nathan Esplin, source=Web Response No relevant relationships by Chen Xu, source=Web Response No relevant relationships by Meilin Young, source=Web Response No relevant relationships by Alexander Yu, source=Web Response