Abstract Number: Esoc2026a554 Bow Hiunter Syndrome - A Case Report

Abstract Background and aims Bow Hunter Syndrome (BHS) was first described in a deer hunter who developed vertebrobasilar stroke while practising archery. The underlying pathophysiology is rotational compression of the vertebral artery within the transverse foramen, leading to haemodynamic compromise and thromboembolism. Methods Retrospective analysis of clinical data and imaging findings from the patient’s medical records with informed consent. Results An 84-year-old patient experienced embolic ischaemic strokes in the left PCA (May 2021) and left PICA territory (June and August 2021). Atherosclerotic large vessel disease was suspected due to a 50% stenosis of the left vertebral artery and dual antiplatelet therapy was initiated. Medical history revealed that all strokes occurred after prolonged leftward head rotation, most recently after sleeping with the head turned. After exclusion of cardioembolic and other competing causes, dynamic neurovascular imaging was performed. Ultrasound showed marked flow reduction in the left V4 segment during head rotation. MR-angiography demonstrated loss of flow signal in the distal left V2 segment when the head was turned left. DSA revealed severe V2 stenosis at C4 with flow delay at 45° rotation and complete occlusion at 60°, with recanalisation in the neutral position. Cervical CT identified a C4 osteophyte causing dynamic narrowing of the transverse foramen. Microsurgical decompression of the vertebral artery at C4 was performed and no further ischaemic events occurred. Conclusions Careful history-taking is essential for suspecting BHS. Dynamic multimodal imaging confirms rotational vertebral artery compression and enables targeted, individualised therapy planning. Conflict of interest All authors: nothing to disclose