Diagnostic Value of Straight Head Hanging in Posterior Canal Benign Paroxysmal Positional Vertigo

Abstract

Background and Purpose To determine the diagnostic value of straight head hanging (SHH) in benign paroxysmal positional vertigo involving the posterior semicircular canal (PC-BPPV). Methods We retrospectively included 62 patients (age=56.2±15.0 years, 47 female) with unilateral PC-BPPV who underwent both the Dix-Hallpike maneuver and SHH before receiving canalith repositioning therapy (CRT) between September 2017 and July 2020 at the Dizziness Center of Seoul National University Bundang Hospital in South Korea (16 patients, 25.8%) or the Neurology Outpatient Clinic of Aerospace Central Hospital in China (46 patients, 74.2%). SHH was performed before ( n =29, group A) or after ( n =33, group B) the Dix-Hallpike maneuver. Results Torsional upbeat nystagmus typical of PC-BPPV was induced during SHH in 52 (83.9%) patients, and the incidence of this type of positional nystagmus did not differ between the groups A and B (79.3% vs. 87.9%, p =0.569). The maximum slow-phase velocity of the induced upbeat nystagmus was higher during SHH than during the Dix-Hallpike maneuver toward the lesion side [range=2.0–60.0°/s (median=18.5°/s) vs. range=2.7–40.0°/s (median=13.4°/s), p <0.001]. Reversal of the positional nystagmus was observed upon resuming the sitting position after SHH in 47 (75.8%) patients and after the Dix-Hallpike maneuver in 54 (87.7%) patients, with no significant difference between the groups ( p =0.082). Conclusions SHH is effective for diagnosing PC-BPPV. Given its simplicity, SHH may be performed before the Dix-Hallpike maneuver, and CRT may be attempted thereafter when the typical positional nystagmus for unilateral PC-BPPV is induced during SHH.

Rapid axial roll test outperforms alternative positional tests in identifying the affected ear in HSC-BPPV: an observational cohort study

“…In fact, the intensity of nystagmus triggered by positional tests depends on the number, size, density of the otoliths, the angle between the semicircular canal plane and the direction of gravity, the moving distance of otolithic debris, the angular acceleration and the amplitude of head motion during the positional tests ( 19 , 20 ). Some scholars reported that they employed SRT alone to identify the affected side of HSC-BPPV, and its accuracy rate was 62% ~ 75% ( 21 ).…”

Canal switch in benign paroxysmal positional vertigo: Clinical characteristics and possible mechanisms

“…Studies have shown that the SPV of nystagmus evoked by the position tests is not only related to the skills of the technicians, the angle between the semicircular canal plane and the gravity vector during the position movement, and the distance that the otolith fragments move ( 23 , 24 ), but also to the number, size and density of the otolith particles ( 25 ). Larger or heavier otolith particles may lead to higher SPV of nystagmus evoked by the position tests.…”

Upbeat and Direction-Changing Torsional Nystagmus While Straight Head Hanging: A New Sign of Benign Paroxysmal Positional Vertigo Involving Bilateral Posterior Semicircular Canals

“…Even though the Dix-Hallpike maneuver remains the gold-standard positioning maneuver for diagnosing PC-BPPV, SHH also evokes the typical positional nystagmus observed in PC-BPPV. 3 In unilateral PC-BPPV, the induced nystagmus would be ipsiversive torsional and upbeat during SHH owing to the otolithic debris migrating away from the ampulla and resultant stimulation of the involved PC. 3 In bilateral PC-BPPV, the induced nystagmus would be mostly upbeat when both PCs are symmetrically affected due to the opposing torsional components being canceled out.…”

“… 3 In unilateral PC-BPPV, the induced nystagmus would be ipsiversive torsional and upbeat during SHH owing to the otolithic debris migrating away from the ampulla and resultant stimulation of the involved PC. 3 In bilateral PC-BPPV, the induced nystagmus would be mostly upbeat when both PCs are symmetrically affected due to the opposing torsional components being canceled out. 4 However, the torsional component in our patient changed from counterclockwise to clockwise, while the upbeat nystagmus remained unchanged.…”