Video Head Impulse Test in the Diagnosis of Benign Paroxysmal Positional Vertigo: A Systematic Review of the Literature

Abstract

Background: Benign paroxysmal positional vertigo (BPPV) is the most common peripheral vestibular disorder and is typically diagnosed based on characteristic positional nystagmus. Although video head impulse testing (vHIT) is increasingly used in vestibular disorders, its role in BPPV remains unclear, particularly in less common variants. This systematic review and meta-analysis aimed to investigate vestibulo-ocular reflex (VOR) gain measured by vHIT in BPPV and to describe vHIT findings in less common variants. Methods: A systematic literature search identified studies reporting vHIT findings in patients with BPPV. For the quantitative synthesis, studies including at least 35 patients with common BPPV variants were eligible, and posterior semicircular canal (PSC) VOR gain was analysed using a random-effects meta-analysis. Less common variants were considered separately without a minimum sample-size criterion and qualitatively synthesised, including case reports, case series, and retrospective and prospective studies. Results: Ten studies met the inclusion criteria for the quantitative synthesis, while one study about typical BPPV underwent qualitative analysis and six studies investigated less common BPPV variants; one of these six studies also contributed to the quantitative synthesis. In typical PSC-BPPV, vHIT generally showed preserved vestibulo-ocular reflex function, with VOR gain within or close to the normal range. The pooled analysis showed no clinically relevant reduction in PSC VOR gain. In less common variants, vHIT findings were heterogeneous, although most patients showed preserved canal-specific VOR function. Conclusions: vHIT appears to have a limited role in the diagnosis of typical BPPV. However, it may provide additional diagnostic information in less common variants, where vestibular responses can be atypical. Further studies with larger and more homogeneous populations are needed to clarify the diagnostic and pathophysiological significance of vHIT findings in uncommon BPPV variants.