Benign paroxysmal positional vertigo (BPPV) involving horizontal semicircular canal (HSCC) is characterized by direction-changing positional nystagmus (DCPN) in a supine roll test, and the occurrence of spontaneous nystagmus in HSCC BPPV has been reported recently. The aim of this study is to investigate the characteristics of pseudo-spontaneous nystagmus (PSN) in patients with HSCC canalolithiasis, and evaluate the effect of the presence of PSN on treatment outcome.Between April 2014 and January 2016, 75 and 59 patients with HSCC canalolithiasis and cupulolithiasis, respectively, were enrolled. Spontaneous and positional nystagmus were examined.PSN was observed in 31 of 75 patients (41%) with HSCC canalolithiasis, and 55 of 59 patients (93%) with HSCC cupulolithiasis. PSN persisted during the period of observation, which was at least 1 minute in all patients with PSN. In HSCC canalolithiasis, direction-reversing nystagmus was observed in 58 patients (25 bilateral and 33 unilateral). Nine of 25 patients with bilateral direction-reversing nystagmus, and 22 of 33 patients with unilateral direction-reversing nystagmus showed PSN. None of 17 patients without direction-reversing nystagmus showed PSN. The direction of PSN corresponded to that of direction-reversing nystagmus in all 22 patients with unilateral direction-reversing nystagmus. The proportion of patients who recovered after 1 session of repositioning maneuver was not significantly different between patients with and without PSN (P = .867).PSN was observed more commonly in HSCC cupulolithiasis than canalolithiasis. The pathophysiologic mechanism underlying PSN can be explained by natural inclination of HSCC and medial to lateral orientation of the HSCC cupular axis in cupulolithiasis, and by spontaneous reversal of initial positional nystagmus (direction-reversing nystagmus) generated by short-term adaptation of vestibulo-ocular reflex in canalolithiasis. The presence of PSN in HSCC canalolithiasis may not affect the treatment outcome.
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http://dx.doi.org/10.1097/MD.0000000000007849 | DOI Listing |
Ann Indian Acad Neurol
September 2023
Department of Neurology, Poona Hospital and Research Centre, Pune, Maharashtra, India.
Otol Neurotol
August 2023
Department of Neurology, Aerospace Center Hospital, Peking University Aerospace School of Clinical Medicine, Beijing, PR China.
Objectives: The occurrence of direction-reversing nystagmus during positional testing in patients with benign paroxysmal positional vertigo (BPPV) is not uncommon. Further in-depth analysis of the characteristics and possible mechanisms of direction-reversing nystagmus will help us to diagnose and treat BPPV more precisely. The study aimed to analyze the incidence and characteristics of direction-reversing nystagmus during positional testing in BPPV patients, evaluate the outcomes of canalith repositioning procedure for these patients, and further explore the possible mechanism of reversal nystagmus in BPPV patients.
View Article and Find Full Text PDFFront Neurol
November 2022
Department of Neurology, Aerospace Center Hospital, Peking University Aerospace School of Clinical Medicine, Beijing, China.
Background: Canal switch-benign paroxysmal positional vertigo (CS-BPPV) refers to the phenomenon in which otolith particles move from one canal to another (on the ipsilateral side) during or after canalith repositioning procedure (CRP). However, the clinical characteristics of CS-BPPV and the underlying pathological mechanisms remain unclear. In this study, we investigated the incidence of canal switch (CS) for the different semicircular canals in benign paroxysmal positional vertigo (BPPV), examined nystagmus characteristics, and explored the underlying mechanisms.
View Article and Find Full Text PDFMedicine (Baltimore)
August 2017
Department of Otorhinolaryngology-Head and Neck Surgery, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Republic of Korea.
Benign paroxysmal positional vertigo (BPPV) involving horizontal semicircular canal (HSCC) is characterized by direction-changing positional nystagmus (DCPN) in a supine roll test, and the occurrence of spontaneous nystagmus in HSCC BPPV has been reported recently. The aim of this study is to investigate the characteristics of pseudo-spontaneous nystagmus (PSN) in patients with HSCC canalolithiasis, and evaluate the effect of the presence of PSN on treatment outcome.Between April 2014 and January 2016, 75 and 59 patients with HSCC canalolithiasis and cupulolithiasis, respectively, were enrolled.
View Article and Find Full Text PDFOtol Neurotol
July 2016
Department of Otorhinolaryngology-Head and Neck Surgery, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Republic of Korea.
Objectives: To investigate the incidence and characteristics of direction-reversing nystagmus in patients with horizontal (HSCC) and posterior semicircular canal (PSCC) canalolithiasis, and evaluate the effect of direction-reversing nystagmus on the treatment outcome.
Study Design: A retrospective study.
Methods: Between March 2014 and September 2015, 63 and 92 consecutive patients with HSCC and PSCC canalolithiasis, respectively, were enrolled.
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