Relationship between the Presence of Nystagmus in the Fourth Position of the Epley Maneuver and Treatment Efficacy for PSC BPPV: A Prospective Study

Objective To investigate whether a specific nystagmus observed during the Epley maneuver can enable immediate reassessment of patients, eliminating the need for deferred diagnosis. Study Design Prospective cohort. Setting Tertiary center. Patients Patients with posterior semicircular canal (PSC) benign paroxysmal positional vertigo (BPPV) diagnosed by the Dix–Hallpike test between March 2022 and March 2023. Interventions All patients were treated with the Epley maneuver. The presence and the characteristics of the nystagmus were recorded in each of the four intermediate positions of the maneuver. Fifteen minutes later, all patients were reevaluated with the Dix–Hallpike test to determine the therapeutic success. Main Outcome Measures Outcome of the Epley maneuver and its relationship with nystagmus characteristics during the four positions of the maneuver. Results Sixty-six patients (77.3% female) were included in the study, of which 66.7% exhibited right PSC BPPV. Therapeutic success of the first Epley maneuver was 74.2%. Almost one third (30.3%) of patients presented with nystagmus in the second and third positions of the Epley maneuver. All patients with down-beating and torsional nystagmus toward the opposite direction of the diagnostic nystagmus in the fourth position of the Epley maneuver needed a second rehabilitative maneuver. None of the patients without nystagmus in this fourth position remained with active BPPV after the first Epley maneuver. Conclusions The presence of nystagmus in the fourth position of the Epley maneuver appears to have a high predictive value, reducing waiting time for a second diagnostic maneuver. Its absence may exempt subsequent reevaluation.