Diagnostic challenges in posterior circulation ischemic stroke presenting with acute dizziness and vertigo.

Posterior circulation stroke (PCS) is a common and clinically important cause of acute dizziness and vertigo, accounting for approximately 20-25% of all acute ischemic strokes. Because PCS frequently presents with non-specific, fluctuating, or isolated vestibular symptoms, it is about three times more likely to be initially missed in emergency care than anterior circulation stroke (ACS), with important consequences for acute treatment, secondary prevention, and patient outcomes. Diagnostic evaluation is further complicated by the low sensitivity of prehospital stroke scales for posterior fossa syndromes, the under-representation of PCS deficits on the National Institutes of Health Stroke Scale (NIHSS), and the limited early sensitivity of non-contrast computed tomography (NCCT) and diffusion-weighted magnetic resonance imaging (DWI-MRI) in the posterior fossa. In contrast, structured bedside assessment can improve recognition when applied by trained clinicians. However, no single diagnostic pathway covers all patients with PCS presenting with acute dizziness and vertigo: the Head Impulse, Nystagmus, and Test of Skew examination (HINTS) and its extension with bedside hearing assessment (HINTS+) require spontaneous or gaze-evoked nystagmus, gait and posture-based approaches require relevant postural instability, and a clinically relevant subgroup presents with neither. This review outlines the main diagnostic challenges along the care pathway and highlights practical opportunities to improve recognition and reduce missed PCS in patients presenting with acute dizziness and vertigo.