Hemi-precession maneuver to treat horizontal canal benign paroxysmal positional vertigo when the affected side is unilateral, bilateral or unknown

Benign paroxysmal positional vertigo (BPPV) is the most common cause of dizziness over the lifespan. The second most commonly affected semicircular canal in BPPV is the horizontal canal, which poses a diagnostic problem and two therapeutic problems. The diagnostic problem is the difficulty of determining the affected side(s) with confidence. This diagnostic uncertainly leads to the first therapeutic problem, which is that one may not know which side to treat. The second therapeutic problem is that because of the approximately co-planar configuration of the horizontal canals, most maneuvers that move otoliths on one side toward the utricle (which is desirable) will also move otoliths on the other side toward the ampulla (which is undesirable) - thus treatment of a given side will "undo" whatever might have been accomplished on the opposite side. Rather than working on the diagnostic dilemma, in this paper we focus on the therapeutic problems by devising a maneuver that leverages the vertical asymmetry of the horizontal canals in order to treat both sides simultaneously.