Fig 1.
(A) Comparison of PSN incidence between canalolithiasis and cupulolithiasis in LC-BPPV patients. Of the 131 LC-BPPV patients, 25 (19.1%) showed PSN in the sitting position with the head perpendicular to the horizontal plane. When divided into subtypes, 7 patients (12.5%) had canalolithiasis and 18 (24%) had cupulolithiasis, and there were no statistically significant differences between the two groups (p = 0.098). (B) Comparison of PSN direction between canalolithiasis and cupulolithiasis in LC-BPPV patients. In the canalolithiasis group, PSN was more likely to be on the healthy side. By contrast, PSN was more often directed toward the affected side in the cupulolithiasis group. However, both directions of PSN occurred in all subtypes. PSN: pseudo-spontaneous nystagmus; LC-BPPV: lateral semicircular canal benign paroxysmal positional vertigo.
Table 1.
Comparison of clinical characteristics according to the presence of PSN in LC-BPPV patients.
Table 2.
Demographic findings between the canalolithiasis group and cupulolithiasis group in LC-BPPV patients.
Fig 2.
Comparison of the incidence of the bow and lean test in PSN-positive and PSN-negative groups.
In the PSN-positive group, all patients had positive bow and lean tests (23/23). In the PSN-negative group, 13 of 87 patients (14.9%) did not show nystagmus in the bow and lean test, which was statistically significant (p = 0.048). PSN: pseudo-spontaneous nystagmus.
Table 3.
Relationship between direction of PSN and the bow and lean test in LC-BPPV patients.