Why continuous nystagmus monitoring matters during treatment of posterior canal BPPV: A case report

Benign paroxysmal positional vertigo (BPPV) due to posterior semicircular canalolithiasis is the most common vestibular disorder, effectively treated with canalith repositioning maneuvers like the Epley maneuver. However, treatment-related complications such as canal switch and canalith jam can occur, necessitating vigilant monitoring of nystagmus. We report a 71-year-old woman who presented with positional vertigo diagnosed as left periampullary posterior canal BPPV. Post-Epley maneuver, she developed spontaneous right-beating nystagmus indicative of canal switch to horizontal semicircular canal with immediate canalith jam, resolved by therapeutic head shaking. The switch to left horizontal canal BPPV (geotropic), was treated with the Gufoni maneuver. Subsequently, a re-switch to non-ampullary arm of posterior canal BPPV occurred, managed with mastoid-augmented demi-Semont maneuver and 45 degrees forced prolonged positioning. Complete resolution was achieved within 24 hours, with negative Dix-Hallpike test. This case underscores the critical role of continuous nystagmus observation during and after repositioning to detect and address rare complications promptly, preventing prolonged symptoms.