title: Persistent Direction-Fixed Nystagmus Following Canalith Repositioning Maneuver for Horizontal Canal BPPV: A Case of Canalith Jam.
abstract: The authors report a 64-year-old man who developed persistent direction fixed nystagmus after a canalith repositioning maneuver for horizontal canal benign paroxysmal positional vertigo (HC-BPPV). The patient was initially diagnosed with right HC-BPPV given that the Dix-Hallpike test showed geotropic horizontal nystagmus that was more pronounced on the right side, although the roll test did not show any positional nystagmus. The patient was treated with a canalith repositioning maneuver (Lempert maneuver). The next day, the patient experienced a different character of dizziness, and left-beating spontaneous nystagmus regardless of head position was observed. After a forced prolonged left decubitus and frequent head shaking, his symptoms and nystagmus resolved. This condition, referred to as canalith jam, can be a complication after the repositioning maneuver in patients with BPPV. Atypical positional tests suggest that abnormal canal anatomy could be the underlying cause of canalith jam.
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Samsung Medical Center, Sunkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Young-Soo
authors.initials: YS
authors.lastname: Chang
authors.affiliation: Soree Ear Clinic, Seoul, Korea.
authors.forename: Jeesun
authors.initials: J
authors.lastname: Choi
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Samsung Medical Center, Sunkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Won-Ho
authors.initials: WH
authors.lastname: Chung
keywords: Benign paroxysmal positional vertigo; Canalith jam; Repositioning maneuver