Dix-Hallpike test primarily assesses which aspect of vestibular function?

Dix-Hallpike test primarily assesses which aspect of vestibular function?

• A. Cerebellar function
• B. Vestibulo-ocular reflex efficiency
• C. Vertigo and nystagmus provoked by head position changes
• D. Hearing thresholds

Answer: (C)

Dix-Hallpike is a test that reveals how the vestibular system responds when head position changes in a way gravity can move debris inside the ear. In most cases of BPPV, small crystals (otoconia) have displaced into the posterior semicircular canal. When the head is moved into a provocative position, these crystals shift with the endolymph, deflecting the canal’s hair cells and triggering stimulation of the vestibulo-ocular reflex. This produces a sensation of vertigo and a characteristic nystagmus, which is observed by the clinician. The key is that the test is designed to evoke vertigo and the accompanying eye movements specifically from positional changes, not to measure general cerebellar function, hearing thresholds, or baseline vestibulo-ocular reflex efficiency.

Dix-Hallpike is a test that reveals how the vestibular system responds when head position changes in a way gravity can move debris inside the ear. In most cases of BPPV, small crystals (otoconia) have displaced into the posterior semicircular canal. When the head is moved into a provocative position, these crystals shift with the endolymph, deflecting the canal’s hair cells and triggering stimulation of the vestibulo-ocular reflex. This produces a sensation of vertigo and a characteristic nystagmus, which is observed by the clinician. The key is that the test is designed to evoke vertigo and the accompanying eye movements specifically from positional changes, not to measure general cerebellar function, hearing thresholds, or baseline vestibulo-ocular reflex efficiency.