The value of nystagmus latency in determination of affected side in horizontal semicircular canal BPPV
WANG Yuyan
ZHANG Xuyang
SAI Long
JIANG Liang
HAN Congli
SUN Yunqiang
ZHOU De
SONG Huiyun
YU Hailing
Abstract：Objective To investigate the value of nystagmus latency in determining the affected side In horizontal semicircular canal benign paroxysmal positional vertigo(BPPV).Methods Patients with horizontal semicircular canal BPPV(n=91)admitted to the Vertigo Clinic of the Department of Otolaryngology,Head and Neck Surgery,Peking University People's Hospital in Qingdao from January 2023 to September 2024 were subjected to bow and supine test(BST),followed by 180°roll test(RT),while observed for nystagmus.Repositioning therapies were performed based on RT results if the side to side ratio of nystagmus intensity was greater than 3:2,or based on BST results if RT failed to indicate the affected side.When the affected side could not be determined by either RT or BST,the longer latency of nystagmus(LON)in RT(at least 1 s)was used to determine the affected side.If failing verification after repositioning,the maneuvers were repeated in the opposite direction.The sensitivity and rate of correct side determination for BST,RT and LON were analyzed.Results Of the 91 patients,nystagmus was induced in 71(78%)by BST.Side determination was successful in 75(82.4%)cases by RT and in 62 cases(68.1%)by LON.The rate of correction side determination was 72.5%(66/91)for BST,78%(71/91)for RT,and 67%(61/91)for LON,respectively(P>0.05).ROC indicated high accuracy in determining the affected side for all three methods.Repositioned was successful in all 91 patients,including 5 whose initial repositioning was erroneous resulting in cupulotolithiasis in 3 patients and in whom repositioning in the opposite direction was successfully.Conclusions Observing nystagmus latency in the 180°RT can significantly improve the rate of success in identification of the affected side in horizontal semicircular canal BPPV without increasing the burden on the patient,and is worthy of clinical adoption.
Keywords：nystagmus latencynystagmus parametershorizontal semicircular canalbenign paroxysmal positional vertigoaffected side determination
Publication Date：2026-01-20
Online Publishing Date：2026-01-17(First online date of this platform, not the publication date of the document)
Pages：6( 32-37 )