A study to determine whether a maneuver to restore positional nystagmus from benign paroxysmal positional vertigo fatigue in posterior-canal-type benign paroxysmal positional vertigo is sufficient for diagnosis.

BACKGROUND: Benign paroxysmal positional vertigo (BPPV) has a characteristic, called BPPV fatigue, in which positional nystagmus (PN) and dizziness symptoms disappear when the patient repeatedly assumes a head position that causes dizziness.

AIMS/OBJECTIVES: We previously developed a new maneuver to restore PN that had disappeared because of BPPV fatigue in posterior-canal-type BPPV (pc-BPPV). This study aimed to demonstrate that the maneuver restores PN from BPPV fatigue to a level sufficient for diagnosing BPPV by macroscopic observation of PN.

MATERIAL AND METHODS: Thirty patients with pc-BPPV underwent the Dix-Hallpike test (DHT) three times, and video recordings of PN were made during the DHTs. Twenty patients underwent the maneuver before the third DHT. The videos were shown to six examiners, who judged whether PN had been restored from BPPV fatigue to a level that allowed diagnosis, including on the affected side.

RESULTS: PN was restored from BPPV fatigue in 18 of the 20 patients who underwent the maneuver, although PN was not restored in all 10 patients who did not undergo the maneuver.

CONCLUSIONS AND SIGNIFICANCE: When BPPV fatigue occurs, the maneuver can induce sufficiently strong PN to diagnose pc-BPPV by macroscopic observation, including on the affected side, with 90% probability.