RT Journal Article SR Electronic T1 P052 Navigating uncertainty: a case study of a subarachnoid haemorrhage with concurrent MCA aneurysm and frontoparietal AVM JF Journal of NeuroInterventional Surgery JO J NeuroIntervent Surg FD BMJ Publishing Group Ltd. SP A55 OP A56 DO 10.1136/jnis-2024-ESMINT.89 VO 16 IS Suppl 2 A1 Sequeira, Alexandra De A1 Ahmed, Danyal A1 Henry, Jack A1 Houlihan, Lena Mary A1 Javadpour, Mohsen YR 2024 UL http://jnis.bmj.com/content/16/Suppl_2/A55.abstract AB Introduction This case of SAH alongside dual imaging findings of MCA aneurysm and AVM, underscores the intricate nature of managing complex intracranial vascular pathologies.Case Description We present a 38 year old, left-handed GCS 15 male presenting with sudden-onset frontal headache with dizziness, nausea, photophobia and ataxia. Non-contrast CT demonstrated subarachnoid haemorrhage (SAH). CTA revealed a wide-necked aneurysm at right M1 bifurcation with a concurrent right frontoparietal arteriovenous malformation (AVM), indicating two potential SAH contributors, introducing ambiguity regarding optimal managementGiven aneurysmal SAH’s higher threat of rebleeding and mortality compared to AVM-related SAH, it was prioritized for clipping via standard pterional approach. After a 41-day recovery period, the AVM was addressed (1, 2). Abstract P052 Figure 1 Abstract P052 Figure 2 The AVM was located posterior to the postcentral gyrus with arterial feeders from MCA branches and drainage into the vein of Labbé and superior sagittal sinus. Proximity to the motor strip, language, and speech areas was of great concern due to the patient’s left-handedness and a WADA test demonstrating ambiguous bihemispheric response. Right parietal craniotomy with trans-sulcal approach was chosen for resection of the Speltzer-Martin 5 AVM. Post-operative CTA confirmed complete resection, on examination patient had right upper limb dysdiadokinesia and minor proprioception impairment. Patient was transferred out of ICU two days post-op and discharged day 7 post-op. Abstract P052 Figure 3 Results From prompt diagnosis to navigating uncertainty, selecting the most likely culprit in an emergent scenario is paramount to mitigating complications and reducing mortality risks. Finally, this case invites multidisciplinary dialogue regarding optimal intervention, whether endovascular or open.