Laboratory Studies
Because the Dix-Hallpike maneuver is pathognomonic, laboratory tests are not needed to make the diagnosis of benign paroxysmal positional vertigo (BPPV). However, since a high association with inner ear disease exists, laboratory workup may be needed to delineate these other pathologies.
Imaging Studies
Imaging studies are not needed in the workup of a patient in whom BPPV is suspected.
Other Tests
See the list below:
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The Dix-Hallpike maneuver is the standard clinical test for BPPV (see Physical).
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Electronystagmography
Torsional eye movement cannot be demonstrated directly, but occasionally electronystagmography (ENG) is helpful in detecting the presence and timing of nystagmus.
Caloric test results can be normal or hypofunctional.
According to Mohammed Hamid, MD, a reduced vestibular response can occur secondary to the sluggishness of the particle-laden endolymph.
BPPV can originate in an ear with an absent caloric response because the nervous and vascular supply to the horizontal canal is separate from that of the PSCs.
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Infrared nystagmography: Torsional eye movement can be demonstrated directly.
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Audiogram: The result of an audiogram may be normal.
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Posturography: Posturography results are often abnormal but follow no predictable or diagnostic pattern.
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The patient is placed in a sitting position with the head turned 45° towards the affected side and then reclined past the supine position.
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The patient is then brought back up to the sitting position.
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Next, the patient is rolled 180° from the affected side to the opposite side. Note that the position of the head is 45° toward the affected side before the roll. The head winds up facing down, 180° away from the starting position.