Atypical Presentation of Posterior Circulation Stroke Unmasking Subclavian Steal Syndrome: A Case Report

Subclavian steal syndrome (SSS) is a rare vascular condition characterised by retrograde flow in the vertebral artery due to proximal subclavian artery stenosis or occlusion.This haemodynamic alteration can compromise posterior cerebral circulation and, in severe cases, precipitate ischaemic stroke.We report the case of a 67-year-old male who presented with acute symptoms suggestive of posterior circulation stroke, including vertigo, diplopia, ataxia, and dysarthria.Clinical examination revealed a significant inter-arm blood pressure discrepancy.Neuroimaging confirmed posterior circulation infarcts, while computed tomography (CT) angiography demonstrated severe proximal left subclavian artery stenosis with retrograde vertebral artery flow, consistent with SSS.The patient was successfully treated with intravenous tenecteplase within the therapeutic window period, resulting in complete neurological recovery.This case highlights the importance of recognising subclavian steal physiology as a potential underlying cause of posterior circulation stroke and underscores the role of timely thrombolysis and multidisciplinary management.