Adverse effect of the Epley maneuver: Anterior canal crisis.

OBJECTIVE: In the Epley maneuver performed on patients with posterior semicircular canal-benign paroxysmal positional vertigo-canalolithiasis (P-BPPV-Can), an intense downbeat nystagmus and retropulsion rarely appear as soon as they reach the last upright sitting position. It is considered an anterior canal crisis that appears when the otoliths move to the ampullofugal direction in the anterior semicircular canal by changing head and body positions from the healthy-ear-down 135° head position (the third head position) to the upright sitting position (the fourth head position). This study aimed to determine the prevention of this anterior canal crisis.

METHODS: The anterior canal crisis frequency was compared among the 178 cases that underwent general Epley maneuver (uncorrected Epley maneuver) and the 228 cases that underwent Epley maneuver (corrected Epley maneuver) by preventing head rotation beyond 135° to the healthy ear and the top of the head going down at the third head position.

RESULTS: In 6% of patients with P-BPPV-Can who underwent the Epley maneuver, a transient mixed downbeat and torsional nystagmus to the affected ear and retropulsion were observed at the fourth head position (anterior canal crisis). The corrected Epley maneuver significantly reduced the incidence of unpredictable anterior canal crisis (p = 0.017). Additionally, there was no difference in the effect of the Epley maneuver the next day regardless of the anterior canal crisis appearance.

CONCLUSION: Anterior canal crisis is an adverse effect of the Epley maneuver, and its prevention is important for safety. Avoiding head rotation beyond 135° to the healthy ear and/or the top of the head going down at the healthy-ear-down 135° head position is expected to reduce anterior canal crisis.