Selective Otolithic and Semicircular Canal Dysfunction: Insights from VEMP and vHIT

Background/Objectives: Vestibular evoked myogenic potentials (VEMPs) and the video head impulse test (vHIT) enable receptor-specific assessment of otolithic organs and semicircular canals. Their increasing use has revealed selective or apparently isolated vestibular abnormalities, although the clinical significance of these findings remains uncertain. This mini-review examines selective otolithic and semicircular canal dysfunction, with emphasis on diagnostic interpretation, methodological limitations, and future research needs. Methods: A structured narrative review of PubMed/MEDLINE and Scopus was conducted, focusing on studies reporting isolated, selective, or disproportionate vestibular abnormalities assessed by VEMPs and/or vHIT. Relevant original studies, case series, case reports, reviews, and diagnostic or consensus papers were considered. Results: Selective otolithic dysfunction may involve the utricle, saccule, or both and is often associated with imbalance, tilting, swaying, spatial disorientation, nausea, or postural instability. Selective semicircular canal dysfunction may involve one or more canals and may present with vertigo, dizziness, nystagmus, or gait instability. Similar VEMP and vHIT patterns occur across vestibular neuritis, Ménière's disease, vestibular migraine, benign paroxysmal positional vertigo, bilateral vestibulopathy, superior semicircular canal dehiscence, vestibular schwannoma, central vestibular disorders, systemic diseases, and idiopathic presentations. Conclusions: Selective vestibular abnormalities should be interpreted as context-dependent laboratory findings rather than discrete disease entities. Their value depends on reproducibility, anatomical plausibility, clinical concordance, complementary testing, and longitudinal follow-up.