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Efficacy of BPPV diagnosis and treatment system for benign paroxysmal positional vertigo
Am J Otolaryngol xxx (xxxx) xxxx
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Efficacy of BPPV diagnosis and treatment system for benign paroxysmal positional vertigo Yue Lou, Miao Cai, Liangguo Xu, Yanwen Wang, Liying Zhuang, Xiaoli Liu
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Department of Neurology, Zhejiang Hospital, Hangzhou 310013, China
A R T I C LE I N FO
A B S T R A C T
Keywords: Benign paroxysmal positional vertigo Dix-Hallpike test Roll test BPPV diagnosis and treatment system
Objectives: To evaluate the efficacy of automatic benign paroxysmal positional vertigo (BPPV) diagnosis and treatment system for BPPV compared with the manual repositioning group. Methods: Two hundred thirty patients diagnosed as idiopathic BPPV who were admitted from August 2018 to July 2019 in Zhejiang Hospital were included. Among them, 150 patients of posterior semicircular canal BPPV (pc-BPPV), 53 patients of horizontal semicircular canal BPPV(hc-BPPV), and 27 patients of horizontal semicircular canal calculus (hc-BPPV-cu) were randomly treated with BPPV diagnosis and treatment system(the experimental group) or manual repositioning (the control group). Resolution of vertigo and nystagmus on the Dix-Hallpike and Roll test on day 3,day 7,day 14 and day 28 follow-up after first treatment was the main outcome measure to assess the efficacy of treatment. Results: At 3-day and 7-day follow-up after treatment with BPPV diagnosis and treatment system, 79%, 91%had complete resolution of vertigo and nystagmus, the effective rate in the experimental group were significantly higher than those in the control group, the differences were statistically significant(P < .05). On day 14, the effective rate in the experimental group (96%) was slightly higher than that in the control group(91%), but there was no significant difference between the two groups. And at 28-day after the first treatment, the effective rate was 100% in the experimental group and the control group. The repositioning efficiency of pc-BPPV (the first, second, third treatment), hc-BPPV (the first, second, third treatment), hc-BPPV-cu(the first, second treatment) in the experimental group were higher than the control group, and the secondary reposition of pc-BPPV in the experimental group was significantly higher than the control group(96%vs.84%; P < .05). While for the hcBPPV-cu patients, the effective rate of the third treatment in the experimental group was slightly lower than that of the control group, but the differences were not statistically significant. Conclusions: BPPV diagnosis and treatment system is effective for the treatment of BPPV, with a better effective rate than those treated with manual maneuver, and is safe and easy to perform on patients.
1. Introduction Benign paroxysmal positional vertigo (BPPV) is the most common type of vertigo, which has received great attention in the past 10 years. It is characterized by brief dizziness and characteristic nystagmus induced by a change in head position with respect to gravity [1].This disease generally occurs in middle-aged and elderly people. Severe cases are often accompanied by temporary nausea and vomiting, lasting no > 1 min. Generally, there is no typical cochlear symptom such as tinnitus and hearing loss. Although BPPV is common in neurological emergency department [2,3], its etiologies are still unclear and head trauma, prolonged lying position and various conditions in the inner ear are potential causes [1].The basic pathophysiological process of
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BPPV is that calcium carbonate particles located on the otolith membrane of the elliptical capsule fall off and enter the semicircular canal. Although BPPV is a self-limiting disease with good prognosis, persistent untreated BPPV may seriously affect patients' daily life [3].In the past, BPPV was generally treated by manual repositioning, but it was impossible for patients with limited physical activity to complete the manual reset, resulting in poor treatment effect. The BPPV diagnosis and treatment system is manufactured by China Medical，is currently one of the most advanced BPPV diagnosis and repositioning equipment in the world. It consists of three parts: hardware system, software system and background workstation. ① The hardware system consists of a fully automatic three-dimensional motion swivel chair and a film acquisition device for wirelessly recording eye
Corresponding author. E-mail address: [email protected] (X. Liu).
https://doi.org/10.1016/j.amjoto.2020.102412 Received 2 December 2019 0196-0709/ © 2020 Elsevier Inc. All rights reserved.
Please cite this article as: Yue Lou, et al., Am J Otolaryngol, https://doi.org/10.1016/j.amjoto.2020.102412
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kidney or severe mental illness.
movements. The fully automatic three-dimensional swivel chair can complete three-dimensional 360° rotation movement under the manipulation of computer, and thus can complete otolith repositioning treatment on patients. The wireless video eye mask displays the eye movement on a computer screen, and can accurately record the direction, type, speed and intensity of nystagmus in any posture. Especially, it can detect weak nystagmus with intensity < 7°/s, which cannot be detected by naked eyes. At the same time, the closed infrared video eye mask can avoid inhibition of visual fixation under the naked eye. ② The software system: it can analyze the data acquired by the wireless goggle and control the speed and angle of the three-dimensional motion swivel chair. ③ The backstage workstation: it can develop examination and treatment plans for BPPV patients and can record the nystagmus parameters. It can film the performance of a patient's eye movement during different degrees of rotation and stimulation and display it on a computer screen. Meanwhile, the direction, type, speed and intensity of nystagmus can be digitized by the equipment and then be conveyed to the physician in the most intuitive way, allowing the medical staff to make judgments on the diagnosis, treatment and efficacy. Our clinical study utilized automatic BPPV diagnosis and treatment system for diagnosis and repositioning treatment on BPPV patients as well as the conventional manual repositioning procedure for comparison analysis, in order to explore effective therapeutic methods for BPPV. In this study, two hundred and thirty patients with BPPV admitted from August 2018 to July 2019 were enrolled in this study. All patients were randomly divided into the experimental group and the control group with 115 patients in each group. The experimental group was treated with the BPPV diagnosis and treatment system, and the control group was treated with manual repositioning. The therapeutic effects on the two groups were evaluated. Herein we report the results.
2.2. Treatment method The patients in the experimental group were treated with an automatic swivel chair in the BPPV diagnosis and treatment system to simulate the repositioning of each semicircular canal BPPV. Three days after the treatment, efficacy of the treatment was evaluated using goggles by Dixhallpike or Roll test. If there was no nystagmus, we considered that the treatment was successful. If Dixhallpike or Roll was still positive, another repositioning treatment would be performed on Day 3 and efficacy of the treatment would be evaluated on day 7.If there were still vertigo and nystagmus a third treatment will be given at 14 days. All patients were evaluated at 28 days to determine if symptoms remained. The patients in the control group were treated with classical manual repositioning by doctors with clinical experience. The timeline to evaluate the treatment efficacy was consistent with the experimental group. The classical manual of Dixhallpike and Roll test was used to evaluate the treatment efficacy of the repositioning. Pc-BPPV patients received either Epley maneuver (the control group) or mimicked Epley maneuver (the experimental group): after performance of Dix–Hallpike maneuver, head was turned 90° toward the unaffected side; head was then turned another 90°, and trunk was turned 90° in the same direction, so that the patient lied on the unaffected side with head pointing toward the floor; patient was then moved to sitting position [1]. Hc-BPPV patients received Barbecue maneuver(the control group) or mimicked Barbecue maneuver(the experimental group): head was rotated in three 90-degree increments, for a total of 270°, from affected ear down, to supine, to unaffected ear down, to prone [1]. Hc-BPPV-cu patients received Gufoni maneuver(the control group) or mimicked Gufoni maneuver(the experimental group):patient lied on the side of affected ear for 1–2 min; head was then rotated 45° in upward position and then assumed sitting position [1].
2. Materials and methods 2.1. Inclusion and exclusion criteria
2.3. Efficacy judgment criteria
Inclusion criteria: according to the Bárány Institute's latest BPPV diagnostic criteria [4], Canalolithiasis of the posterior canal (pcBPPV):A. Recurrent attacks of positional vertigo or positional dizziness provoked by lying down or turning over in the supine position [5]; B. Duration of attacks < 1 min; C. Positional nystagmus elicited after a latency of one or few seconds by the Dix-Hallpike maneuver or sidelying maneuver (Semont diagnostic maneuver) [6]. The nystagmus is a combination of torsional nystagmus with the upper pole of the eyes beating toward the lower ear combined with vertical nystagmus beating upward (toward the forehead) typically lasting < 1 min; D. Not attributable to another disorder. Canalolithiasis of the horizontal canal (hcBPPV):A. Recurrent attacks1 of positional vertigo or positional dizziness provoked by lying down or turning over in the supine position; B. Duration of attacks < 1 min [7]; C. Positional nystagmus elicited after a brief latency or no latency [6] by the supine roll test, beating horizontally [8] toward the undermost ear [9,10] with the head turned to either side (geotropic direction changing nystagmus) and lasting < 1 min; D. Not attributable to another disorder. Cupulolithiasis of the horizontal canal (hc-BPPV-cu):A. Recurrent attacks of positional vertigo or positional dizziness provoked by lying down or turning over in the supine position; B. Positional nystagmus [7] elicited after a brief latency or no latency by the supine roll test, beating horizontally toward the uppermost ear with the head turned to either side (apogeotropic direction changing nystagmus), and lasting > 1 min; C. Not attributable to another disorder. Exclusion criteria: A. Non-BPPV patients with negative vestibular induction test; B.Central vertigo caused by posterior fossa lesions or vestibular neuroma; C. Other forms of peripheral vertigo, such as vestibular neuritis or labyrinthitis, Meniere's disease and other inner ear related vertigo patients; D. Patients with severe heart, liver, lung,
The first follow-up time was Day 3 after treatment (Day 0). The Dixhallpike and Roll test were performed by manual maneuver or BPPV diagnosis and treatment system to evaluate the efficacy. If the nystagmus disappeared, it was considered as a successful treatment. If the nystagmus still existed, the patient would be treated one more time. We then evaluated the efficacy on Day 7, Day 14 and Day 28. 2.4. Evaluated of recurrence rate 5 months after the first treatment, we followed up with BPPV patients and evaluated the recurrence rate of these patients. The diagnosis criteria of recurrence are based on relapse symptoms of positional vertigo and characteristic nystagmus were observed that treated by DixHallpike or Roll test [11]. 2.5. Statistical analysis Statistical analysis was performed using SPSS 22.0. In the comparison of qualitative variable, which was expressed in n/%, the χ 2 test was performed. Fisher's exact test was used when the cells contained showed values < 5.Quantitative variables were expressed as mean ± standard deviation (SD). In the univariate analysis, comparisons of numerical parameters between both groups were performed using the Student‘s t-test. Significance was set at p < .05. 3. Results All patients were randomly divided into the experimental group 2
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slightly higher than the total costs of the control group (410.4 ± 417.9 yuan). The main reason is that the repositioning treatment cost of experimental group (401.7 ± 227.9 yuan) is higher than that of the control group (167.0 ± 105.7 yuan). However, other costs during the entire treatment process including registration fee(20.1 ± 11.4 yuan vs. 25.0 ± 15.9 yuan), medicine fee(9.8 ± 19.2 yuan vs. 15.9 ± 22.3 yuan), and examination fee(124.6 ± 243.7 yuan vs. 202.5 ± 283.9 yuan), were lower in the experimental group than that of the control group(Table 6). Five months after the first treatment, we followed up with BPPV patients and evaluated the recurrence rate of these patients. The lost follow-up rate in the experimental group was 3.5%, including 2 cases of p-BPPV, 1 case of hc-BPPV, and 1 case of hc-BPPV-cu. The lost followup rate in the control group was 4.3%, including 3 cases of p-BPPV, 1 case of hc-BPPV, and 1 case of hc-BPPV-cu, there was no significant difference between the two groups in the rate of lost follow-up (P value 1.0).Five months after the first treatment, the recurrence rate in the experimental group was 20.7%, which was 26.4% in the control group, there was no significant difference in recurrence rates between the two groups (P value .323). For the pc-BPPV patients (19.2%vs.25%, P value 0.398), hc-BPPV patients (24%vs.26.9%, P value 0.811) and the hcBPPV-cu patients (23.1%vs.33.3%, P value 0.673),there were no statistically significant difference in recurrence rates between the experimental group and the control group.
(BPPV diagnosis and treatment system with repositioning treatment) and the control group (classical manual repositioning treatment) with 115 cases in each group. Demographics and clinical characteristics of the studied groups are shown in Table1. Three days after the first treatment, positional vertigo and nystagmus was not observed in 91 (79%) patients of the experimental group, compared with 74 (64%) of the control group (P < .05).For the rest patients who still had the symptoms on Day 3, one more repositioning treatment was performed on Day 3 and the efficacy of the treatments was evaluated on Day 7.On Day 7,positional vertigo and nystagmus was not observed in a total of 105 patients in the experimental group, an effective rate of 91%, while only 90 patients in the control group was considered effective in treatment, an effective rate of 78%, the difference between the two groups was statistically significant (P < .05). For the rest patients who still had the symptoms after the second treatment, the third treatment was performed on Day 7 and the efficacy of the treatments was evaluated on Day 14. On Day 14, positional vertigo and nystagmus was not observed in a total of 110 patients in the experimental group, an effective rate of 96%, while 105 patients in the control group was considered effective in treatment, an effective rate of 91%, the effective rate in the experimental group was slightly higher than that in the control group, but there was no significant difference between the two groups (P value 0.182) (Tables 1 and 2) 0.28 days after the first treatment, we evaluated all patients through the Dix-Hallpike and Roll test and found that the effective rate was 100% in both the experimental group and the control group. We further divided the BPPV patients into pc-BPPV, hc-BPPV and hc-BPPV-cu subgroups, and analyzed the differences between the experimental group and the control group. For the pc-BPPV patients, the effective rate of the experimental group was higher than that of the control group (84%vs.71%)after the first treatment, although the difference did not achieve statistical significance (P = .078) (Table 3).After the second treatment, the effective rate of the experimental group reached 96%, in comparison with an effective rate of 84% of the control group, and statistical analysis showed significant improvement (P < .05) (Table 3). After the third treatment, the effective rate of the experimental group reached 100%, which was higher than 93% in the control group, but there was no significant difference between the two groups (Table 3). For the hc-BPPV patients, the effective rates of the first(81% vs.67%), second(92% vs.81%), and third(100% vs.96%) treatments were higher in the experimental group than those of the control group; and for the hc-BPPV-cu patients, the effective rates of the first(50% vs.23%), second(64% vs.38%) treatments were higher in the experimental group than those of the control group, while the effective rate of the third treatment(64% vs.69%)in the experimental group was slightly lower than that of the control group, the differences were not statistically significant, possibly due to low sample sizes (Tables 4 and 5). The patients who are not cured with the first repositioning treatment will be given MRI examination to rule out vertigo caused by other reasons, and they will be given oral betaestine to relieve the symptoms of vertigo. Therefore, the cost of BPPV patients includes the registration fee for each visit (RMB 15 yuan), the cost of each manual repositioning treatment (100 yuan) or BPPV diagnosis and treatment system repositioning treatment (300 yuan), the cost of medicine fee (betaestine 47 yuan/box), and MRI examination fee (597 yuan). The total costs of treatment in the experimental group (556.2 ± 486.0 yuan) were
4. Discussion Classical manual repositioning is an effective treatment and is recommended by the American Academy of Otolaryngology-Head and Neck Surgery's [5] guideline for posterior semicircular canal BPPV (Epley's maneuver), horizontal canal semicircular BPPV(Barbecue's maneuver) and cupulolithiasis of the horizontal canal BPPV(Gufoni's maneuver) [1,7].However, some patients are inconvenient in manual reposition because of limited physical mobility, obesity, severe cervical spondylosis [12], patients with refractory BPPV, etc. Recently, computer-controlled repositioning procedure has been applied to the treatment of BPPV, which has done a great help to patients who have difficulty in classical manual repositioning [6,8].In the study of Nakayama and Epley, it shows that the automated nystagmus-based repositioning is beneficial in BPPV treatment [9]. Xizheng et al. found that in 132 patients with pc-BPPV treated with computer-controlled repositioning, the effective rate was 81.8% [6], similar to our findings. Wang et al. compared the results of pc-BPPV patients treated with onetime automatic repositioning and one-time manual repositioning, and they found that the effective rates was slightly higher in the automatic repositioning group (90.90% vs. 86.96%) [10]. We found that 91 (79%) of 115 BPPV patients who were treated with BPPV diagnosis and treatment system had symptoms disappeared after the first treatment, compared with 74 (64%) of 115 BPPV patients treated with classical manual repositioning. After the second treatment, the effective rate of the patients in the BPPV diagnosis and treatment system group was 91%, while the effective rate of the manual repositioning group was 78%.After the third treatment, the effective rate was 96% in the experimental group, which was 91% in the control group, the effective rate in the experimental group was slightly higher than that in the control group, but there was no significant difference between the two groups. Furthermore, when the patients were sub-
Table 1 Comparison of clinical characteristics between experimental group and control group.
Age of onset Sex ratio(male: female) Side ratio(left:right)
The experimental group(n = 115)
The control group(n = 115)
P value
54(23–87) 1:1.95 1:0.98
53(23–84) 1:1.56 1:1.09
0.97 0.49 0.72
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Table 2 Comparison of efficacy between the experimental group and control group. No nystagmus
The experimental group(n = 115)
The control group(n = 115)
P value
First treatment; n(%) Second treatment; n(%) Third treatment; n(%)
91(79) 105(91) 110(96)
74(64) 90(78) 105(91)
< .05 < .05 .182
Table 3 Comparison of efficacy between experimental group and control group of pc-BPPV patients. No nystagmus
The experimental group(n = 75)
The control group(n = 75)
P value
First treatment; n(%) Second treatment; n(%) Third treatment; n(%)
63(84) 72(96) 75(100)
53(71) 63(84) 70(96)
.078 < .05 .058
Table 4 Comparison of efficacy between experimental group and control group of hc-BPPV patients. No nystagmus
The experimental group(n = 26)
The control group(n = 27)
P value
First treatment; n(%) Second treatment; n(%) Third treatment; n(%)
21(81) 24(92) 25(100)
18(67) 22(81) 25(96)
.352 .420 1.000
Table 5 Comparison of efficacy between experimental group and control group of hc-BPPV-cu patients. No nystagmus
The experimental group(n = 14)
The control group(n = 13)
P value
First treatment; n(%) Second treatment; n(%) Third treatment; n(%)
7(50) 9(64) 9(64)
3(23) 5(38) 9(69)
.236 .257 1.000
Table 6 Comparison of costs between experimental group and control group.
Repositioning treatment fee (RMB Yuan), mean ± SD Registration fee, mean ± SD Medicine fee (RMB Yuan), mean ± SD examination fee,(RMB Yuan), mean ± SD Total cost (RMB Yuan), mean ± SD
The experimental group(n = 115)
The control group(n = 115)
P value
401.7 ± 227.9 20.1 ± 11.4 9.8 ± 19.2 124.6 ± 243.7 556.2 ± 486.0
167.0 ± 105.7 25.0 ± 15.9 15.9 ± 22.3 202.5 ± 283.9 410.4 ± 417.9
< .05 < .05 < .05 < .05 < .05
repositioning treatment had a more stable long-term efficacy and a lower recurrence rate [8]. However, the sample sizes of these studies were small, and the efficacy of BPPV diagnosis and treatment system in the treatment of horizontal semicircular canal BPPV is still unclear. We evaluated the BPPV patients at 5 months of first repositioning, Five months after the first repositioning, the BPPV patients were evaluated and we found that the recurrence rate was close to previously reported. In our research, the recurrence rate in the experimental group was 20.7%, which was 26.4% in the control group, the BPPV diagnosis and treatment system had a lower recurrence rate, but there was no significant difference between the two groups. We further divided the BPPV patients into pc-BPPV, hc-BPPV and hc-BPPV-cu subgroups, for the pc-BPPV patients(19.2%vs.25%, P value 0.398), hc-BPPV patients (24%vs.26.9%, P value 0.811)and the hc-BPPV-cu patients(23.1% vs.33.3%, P value 0.673),the BPPV diagnosis and treatment system had a lower recurrence rate, but there were still no statistically significant difference between the two groups. In previous studies, there was a hypothesis that the fragments of otoliths maybe dispersed into the semicircular canal during the repositioning process, which required more than one repositioning maneuver to succeed. And the residual otolith may lead to an increase in the recurrence rate [15]. Our research found that the effective rate of the first and second repositioning
grouped to pc-BPPV, hc-BPPV and hc-BPPV-cu, we found that for pcBPPV patients, the effective rate after the second treatment was significantly higher in the experimental group than that of the control group. However, there was no significant difference between the two treatment groups for the hc-BPPV and the hc-BPPV-cu, which may be due to small sample sizes. We thus conclude that the BPPV diagnosis and treatment system has certain advantages compared with the manual repositioning. The former can move the otolith in the semicircular canal at a specific speed, rotation and precise plane, so that all patients could receive a standard repositioning treatment. At the same time, in the repositioning process, the nystagmus and the position of the semicircular canal can be observed and recorded in real time, so the accuracy of the repositioning is improved. In addition, the BPPV diagnosis and treatment system is highly safe, especially for patients with difficulty in manual repositioning treatment. Moreover, the eldest patients enrolled in this study were 87 years old, and he was well tolerated to the BPPV diagnosis and treatment system. BPPV is prone to recurrence, and the recurrence rate varies with time, ranging from 16% to 36% [13,14]. Liu et al. found that the 6month recurrence rate of pc-BPPV was 3% after automated mechanical repositioning treatment, while the 6-month recurrence rate was 8.9% in the manual repositioning group, and the automated mechanical
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Availability of data and materials
maneuver in the experimental group is higher than that in the experimental group. As mentioned before, the angle and speed during the manual maneuver are not as accurate as the machine maneuver, resulting in some otoliths remaining in the semicircular canal. This may also be the reason why the recurrence rate in the experimental group was slightly lower than that in the control group at the 5-month followup. In addition, patients with underlying diseases such as Meniere's disease, hypertension, migraine, and hyperlipidemia are also considered to be independent risk factors for BPPV recurrence [16].Due to so many factors involved in recurrence, the recurrence rates of the two groups did not reach a significant difference. At the same time, we calculated the cost of treatment for patients with BPPV. The total costs of treatment in the experimental group were slightly higher than the total costs of the control group. The main reason is that the repositioning treatment cost of experimental group is higher than that of the control group. However, other costs during the entire treatment process including registration fee, medicine fee and examination fee were lower in the experimental group than that of the control group. In addition, the prolonged duration of vertigo in the manual repositioning group will lead to longer time of lost working for patients than the machine repositioning group, which will increase the lost wages. However, due to the difference in work types of each patient, this cost cannot be accurately evaluated. However, this study has some limitations. First, this is a retrospective case-control study that provides only Level III evidence. Second, the sample size of hc-BPPV and hc-BPPV-cu was small, no significant difference was found between the two treatment groups. Third, although we observed a short-term efficacy after repositioning and a 5-month follow-up to determine the long-term efficacy, longer follow-up study is needed to determine the long-term efficacy of the BPPV diagnosis and treatment system. Fourth, previous studies showed that canal conversion is a common phenomenon occurring after repositioning treatment, in about 6–7% pc-BPPV patients treated with EM [1].It is worth to pay attention to the effect on canal conversion in future studies.
All data generated during this study are available from the corresponding author upon reasonable request. Authors' contributions YL contributed to manuscript writing and interpretation of the data. MC and LX contributed to acquisition of the data. YW and LZ contributed to interpretation of the data. XL contributed to the critical revision of the manuscript for intellectual content. All authors read and approved the final manuscript. Declaration of competing interest Nothing was received by we and our institution from the company that makes the BPPV Diagnosis and Treatment System used to test and treat patients referenced in our manuscript and study, and there are no conflicts of interest to be reported by the authors of this study. Acknowledgements This work was supported by the Natural Science Foundation of Zhejiang Province under Grant No. LQ19H090006; the Department of Health of Zhejiang Province under Grant No. 2019KY260. References [1] Kim JS, Zee DS. Clinical practice. Benign Paroxysmal Positional VertigoN Engl J Med 2014 Mar 20;370(12):1138–47. [2] Heidenreich KD. Images in clinical medicine. Benign paroxysmal positional vertigo. N Engl J Med. 2010 Jun 24;362(25):e70. [3] Parnes LS, Agrawal SK, Atlas J. Diagnosis and management of benign paroxysmalpositional vertigo (BPPV). CMAJ. 2003 Sep 30;169(7):681–93. [4] Bertholon P, Brandt T, Fife T, et al. Benign paroxysmal positional vertigo: Diagnostic criteria. J Vestib Res. 2015;25(3–4):105–17. [5] Bhattacharyya N, Gubbels SP, Schwartz SR, et al. Clinical practice guideline: benign paroxysmal positional vertigo (update) executive summary. Otolaryngology Head and Neck Surgery 2017;156(3):403–16. [6] Shan X, Peng X, Wang E. Efficacy of computer-controlled repositioning procedure for benign paroxysmal positional vertigo. Laryngoscope. 2015 Mar;125(3):715–9. [7] van Duijn JG, Isfordink LM, Nij Bijvank JA, et al. Rapid systematic review of the epley maneuver for treating posterior canal benign paroxysmal positional vertigo. Otolaryngol Head Neck Surg 2014 Jun;150(6):925–32. [8] Liu X, Treister R, Yan Y, et al. Automated mechanical repositioning treatment for posterior canal benign paroxysmal positional vertigo: a single-center experience and literature review. Eur Neurol 2017;78(5–6):240–6. [9] Nakayama M, Epley JM, et al. BPPV and variants: improved treatment results with automated, nystagmus-based repositioning. Otolaryngol. Head Neck Surg. 2005;133(1):107–12. [10] Wang N, Zhou H, Huang H, et al. Efficacy of SRM-IV vestibular function. diagnosis and treatment system in treating benign paroxysmal positional vertigo. Iran J Public Health. 2018 May;47(5):641–7. [11] Luryi AL, Lawrence J, Bojrab DI, et al. Recurrence in benign paroxysmal positional vertigo: a large, single-institution study. Otol Neurotol 2018 Jun;39(5):622–7. [12] Kollén L, Frändin K, Möller M, et al. Benign paroxysmal positional vertigo is a common cause of dizziness and unsteadiness in a large population of 75-year-olds. Aging Clin Exp Res 2012 Aug;24(4):317–23. [13] Song CI, Kang BC, Yoo MH, et al. Management of 210 patients with benign paroxysmal positional vertigo: AMC protocol and outcomes. Acta Otolaryngol. 2015 May;135(5):422–8. [14] Amor-dorado JC, Barreira-ferna MP, Aran-gonzalez I, et al. Particle repositioning maneuver versus Brandt-Daroff exercise for treatment of unilateral idiopathic BPPV of the posterior semicircular canal: a randomized prospective clinical trial with short- and long-term outcome. Otol Neurotol. 2012 Oct;33(8):1401–7. [15] Dispenza F, Mazzucco W, Mazzola S, et al. Observational study on risk factors determining residual dizziness after successful benign paroxysmal positional vertigo treatment: the role of subclinical BPPV. Acta Otorhinolaryngol Ital 2019 Oct;39(5):347–52. [16] Zhu CT, Zhao XQ, Ju Y, et al. Clinical characteristics and risk factors for the recurrence of benign paroxysmal positional vertigo. Front Neurol. 2019;13(10):1190.
5. Conclusions In summary, the BPPV diagnosis and treatment system is superior to the traditional manual repositioning in some aspects. Its long-term clinical efficacy and safety require further evaluation with a larger sample size. Abbreviations BPPV benign paroxysmal positional vertigo pc-BPPV Canalolithiasis of the posterior canal benign paroxysmal positional vertigo hc-PBBV Canalolithiasis of the horizontal canal benign paroxysmal positional vertigo hc-BPPV-cu Cupulolithiasis of the horizontal canal benign paroxysmal positional vertigo EM Epley's maneuver Compliance with ethical standards All procedures performed in this study involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
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Am J Otolaryngol journal homepage: www.elsevier.com/locate/amjoto
Efficacy of BPPV diagnosis and treatment system for benign paroxysmal positional vertigo Yue Lou, Miao Cai, Liangguo Xu, Yanwen Wang, Liying Zhuang, Xiaoli Liu
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Department of Neurology, Zhejiang Hospital, Hangzhou 310013, China
A R T I C LE I N FO
A B S T R A C T
Keywords: Benign paroxysmal positional vertigo Dix-Hallpike test Roll test BPPV diagnosis and treatment system
Objectives: To evaluate the efficacy of automatic benign paroxysmal positional vertigo (BPPV) diagnosis and treatment system for BPPV compared with the manual repositioning group. Methods: Two hundred thirty patients diagnosed as idiopathic BPPV who were admitted from August 2018 to July 2019 in Zhejiang Hospital were included. Among them, 150 patients of posterior semicircular canal BPPV (pc-BPPV), 53 patients of horizontal semicircular canal BPPV(hc-BPPV), and 27 patients of horizontal semicircular canal calculus (hc-BPPV-cu) were randomly treated with BPPV diagnosis and treatment system(the experimental group) or manual repositioning (the control group). Resolution of vertigo and nystagmus on the Dix-Hallpike and Roll test on day 3,day 7,day 14 and day 28 follow-up after first treatment was the main outcome measure to assess the efficacy of treatment. Results: At 3-day and 7-day follow-up after treatment with BPPV diagnosis and treatment system, 79%, 91%had complete resolution of vertigo and nystagmus, the effective rate in the experimental group were significantly higher than those in the control group, the differences were statistically significant(P < .05). On day 14, the effective rate in the experimental group (96%) was slightly higher than that in the control group(91%), but there was no significant difference between the two groups. And at 28-day after the first treatment, the effective rate was 100% in the experimental group and the control group. The repositioning efficiency of pc-BPPV (the first, second, third treatment), hc-BPPV (the first, second, third treatment), hc-BPPV-cu(the first, second treatment) in the experimental group were higher than the control group, and the secondary reposition of pc-BPPV in the experimental group was significantly higher than the control group(96%vs.84%; P < .05). While for the hcBPPV-cu patients, the effective rate of the third treatment in the experimental group was slightly lower than that of the control group, but the differences were not statistically significant. Conclusions: BPPV diagnosis and treatment system is effective for the treatment of BPPV, with a better effective rate than those treated with manual maneuver, and is safe and easy to perform on patients.
1. Introduction Benign paroxysmal positional vertigo (BPPV) is the most common type of vertigo, which has received great attention in the past 10 years. It is characterized by brief dizziness and characteristic nystagmus induced by a change in head position with respect to gravity [1].This disease generally occurs in middle-aged and elderly people. Severe cases are often accompanied by temporary nausea and vomiting, lasting no > 1 min. Generally, there is no typical cochlear symptom such as tinnitus and hearing loss. Although BPPV is common in neurological emergency department [2,3], its etiologies are still unclear and head trauma, prolonged lying position and various conditions in the inner ear are potential causes [1].The basic pathophysiological process of
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BPPV is that calcium carbonate particles located on the otolith membrane of the elliptical capsule fall off and enter the semicircular canal. Although BPPV is a self-limiting disease with good prognosis, persistent untreated BPPV may seriously affect patients' daily life [3].In the past, BPPV was generally treated by manual repositioning, but it was impossible for patients with limited physical activity to complete the manual reset, resulting in poor treatment effect. The BPPV diagnosis and treatment system is manufactured by China Medical，is currently one of the most advanced BPPV diagnosis and repositioning equipment in the world. It consists of three parts: hardware system, software system and background workstation. ① The hardware system consists of a fully automatic three-dimensional motion swivel chair and a film acquisition device for wirelessly recording eye
Corresponding author. E-mail address: [email protected] (X. Liu).
https://doi.org/10.1016/j.amjoto.2020.102412 Received 2 December 2019 0196-0709/ © 2020 Elsevier Inc. All rights reserved.
Please cite this article as: Yue Lou, et al., Am J Otolaryngol, https://doi.org/10.1016/j.amjoto.2020.102412
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kidney or severe mental illness.
movements. The fully automatic three-dimensional swivel chair can complete three-dimensional 360° rotation movement under the manipulation of computer, and thus can complete otolith repositioning treatment on patients. The wireless video eye mask displays the eye movement on a computer screen, and can accurately record the direction, type, speed and intensity of nystagmus in any posture. Especially, it can detect weak nystagmus with intensity < 7°/s, which cannot be detected by naked eyes. At the same time, the closed infrared video eye mask can avoid inhibition of visual fixation under the naked eye. ② The software system: it can analyze the data acquired by the wireless goggle and control the speed and angle of the three-dimensional motion swivel chair. ③ The backstage workstation: it can develop examination and treatment plans for BPPV patients and can record the nystagmus parameters. It can film the performance of a patient's eye movement during different degrees of rotation and stimulation and display it on a computer screen. Meanwhile, the direction, type, speed and intensity of nystagmus can be digitized by the equipment and then be conveyed to the physician in the most intuitive way, allowing the medical staff to make judgments on the diagnosis, treatment and efficacy. Our clinical study utilized automatic BPPV diagnosis and treatment system for diagnosis and repositioning treatment on BPPV patients as well as the conventional manual repositioning procedure for comparison analysis, in order to explore effective therapeutic methods for BPPV. In this study, two hundred and thirty patients with BPPV admitted from August 2018 to July 2019 were enrolled in this study. All patients were randomly divided into the experimental group and the control group with 115 patients in each group. The experimental group was treated with the BPPV diagnosis and treatment system, and the control group was treated with manual repositioning. The therapeutic effects on the two groups were evaluated. Herein we report the results.
2.2. Treatment method The patients in the experimental group were treated with an automatic swivel chair in the BPPV diagnosis and treatment system to simulate the repositioning of each semicircular canal BPPV. Three days after the treatment, efficacy of the treatment was evaluated using goggles by Dixhallpike or Roll test. If there was no nystagmus, we considered that the treatment was successful. If Dixhallpike or Roll was still positive, another repositioning treatment would be performed on Day 3 and efficacy of the treatment would be evaluated on day 7.If there were still vertigo and nystagmus a third treatment will be given at 14 days. All patients were evaluated at 28 days to determine if symptoms remained. The patients in the control group were treated with classical manual repositioning by doctors with clinical experience. The timeline to evaluate the treatment efficacy was consistent with the experimental group. The classical manual of Dixhallpike and Roll test was used to evaluate the treatment efficacy of the repositioning. Pc-BPPV patients received either Epley maneuver (the control group) or mimicked Epley maneuver (the experimental group): after performance of Dix–Hallpike maneuver, head was turned 90° toward the unaffected side; head was then turned another 90°, and trunk was turned 90° in the same direction, so that the patient lied on the unaffected side with head pointing toward the floor; patient was then moved to sitting position [1]. Hc-BPPV patients received Barbecue maneuver(the control group) or mimicked Barbecue maneuver(the experimental group): head was rotated in three 90-degree increments, for a total of 270°, from affected ear down, to supine, to unaffected ear down, to prone [1]. Hc-BPPV-cu patients received Gufoni maneuver(the control group) or mimicked Gufoni maneuver(the experimental group):patient lied on the side of affected ear for 1–2 min; head was then rotated 45° in upward position and then assumed sitting position [1].
2. Materials and methods 2.1. Inclusion and exclusion criteria
2.3. Efficacy judgment criteria
Inclusion criteria: according to the Bárány Institute's latest BPPV diagnostic criteria [4], Canalolithiasis of the posterior canal (pcBPPV):A. Recurrent attacks of positional vertigo or positional dizziness provoked by lying down or turning over in the supine position [5]; B. Duration of attacks < 1 min; C. Positional nystagmus elicited after a latency of one or few seconds by the Dix-Hallpike maneuver or sidelying maneuver (Semont diagnostic maneuver) [6]. The nystagmus is a combination of torsional nystagmus with the upper pole of the eyes beating toward the lower ear combined with vertical nystagmus beating upward (toward the forehead) typically lasting < 1 min; D. Not attributable to another disorder. Canalolithiasis of the horizontal canal (hcBPPV):A. Recurrent attacks1 of positional vertigo or positional dizziness provoked by lying down or turning over in the supine position; B. Duration of attacks < 1 min [7]; C. Positional nystagmus elicited after a brief latency or no latency [6] by the supine roll test, beating horizontally [8] toward the undermost ear [9,10] with the head turned to either side (geotropic direction changing nystagmus) and lasting < 1 min; D. Not attributable to another disorder. Cupulolithiasis of the horizontal canal (hc-BPPV-cu):A. Recurrent attacks of positional vertigo or positional dizziness provoked by lying down or turning over in the supine position; B. Positional nystagmus [7] elicited after a brief latency or no latency by the supine roll test, beating horizontally toward the uppermost ear with the head turned to either side (apogeotropic direction changing nystagmus), and lasting > 1 min; C. Not attributable to another disorder. Exclusion criteria: A. Non-BPPV patients with negative vestibular induction test; B.Central vertigo caused by posterior fossa lesions or vestibular neuroma; C. Other forms of peripheral vertigo, such as vestibular neuritis or labyrinthitis, Meniere's disease and other inner ear related vertigo patients; D. Patients with severe heart, liver, lung,
The first follow-up time was Day 3 after treatment (Day 0). The Dixhallpike and Roll test were performed by manual maneuver or BPPV diagnosis and treatment system to evaluate the efficacy. If the nystagmus disappeared, it was considered as a successful treatment. If the nystagmus still existed, the patient would be treated one more time. We then evaluated the efficacy on Day 7, Day 14 and Day 28. 2.4. Evaluated of recurrence rate 5 months after the first treatment, we followed up with BPPV patients and evaluated the recurrence rate of these patients. The diagnosis criteria of recurrence are based on relapse symptoms of positional vertigo and characteristic nystagmus were observed that treated by DixHallpike or Roll test [11]. 2.5. Statistical analysis Statistical analysis was performed using SPSS 22.0. In the comparison of qualitative variable, which was expressed in n/%, the χ 2 test was performed. Fisher's exact test was used when the cells contained showed values < 5.Quantitative variables were expressed as mean ± standard deviation (SD). In the univariate analysis, comparisons of numerical parameters between both groups were performed using the Student‘s t-test. Significance was set at p < .05. 3. Results All patients were randomly divided into the experimental group 2
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slightly higher than the total costs of the control group (410.4 ± 417.9 yuan). The main reason is that the repositioning treatment cost of experimental group (401.7 ± 227.9 yuan) is higher than that of the control group (167.0 ± 105.7 yuan). However, other costs during the entire treatment process including registration fee(20.1 ± 11.4 yuan vs. 25.0 ± 15.9 yuan), medicine fee(9.8 ± 19.2 yuan vs. 15.9 ± 22.3 yuan), and examination fee(124.6 ± 243.7 yuan vs. 202.5 ± 283.9 yuan), were lower in the experimental group than that of the control group(Table 6). Five months after the first treatment, we followed up with BPPV patients and evaluated the recurrence rate of these patients. The lost follow-up rate in the experimental group was 3.5%, including 2 cases of p-BPPV, 1 case of hc-BPPV, and 1 case of hc-BPPV-cu. The lost followup rate in the control group was 4.3%, including 3 cases of p-BPPV, 1 case of hc-BPPV, and 1 case of hc-BPPV-cu, there was no significant difference between the two groups in the rate of lost follow-up (P value 1.0).Five months after the first treatment, the recurrence rate in the experimental group was 20.7%, which was 26.4% in the control group, there was no significant difference in recurrence rates between the two groups (P value .323). For the pc-BPPV patients (19.2%vs.25%, P value 0.398), hc-BPPV patients (24%vs.26.9%, P value 0.811) and the hcBPPV-cu patients (23.1%vs.33.3%, P value 0.673),there were no statistically significant difference in recurrence rates between the experimental group and the control group.
(BPPV diagnosis and treatment system with repositioning treatment) and the control group (classical manual repositioning treatment) with 115 cases in each group. Demographics and clinical characteristics of the studied groups are shown in Table1. Three days after the first treatment, positional vertigo and nystagmus was not observed in 91 (79%) patients of the experimental group, compared with 74 (64%) of the control group (P < .05).For the rest patients who still had the symptoms on Day 3, one more repositioning treatment was performed on Day 3 and the efficacy of the treatments was evaluated on Day 7.On Day 7,positional vertigo and nystagmus was not observed in a total of 105 patients in the experimental group, an effective rate of 91%, while only 90 patients in the control group was considered effective in treatment, an effective rate of 78%, the difference between the two groups was statistically significant (P < .05). For the rest patients who still had the symptoms after the second treatment, the third treatment was performed on Day 7 and the efficacy of the treatments was evaluated on Day 14. On Day 14, positional vertigo and nystagmus was not observed in a total of 110 patients in the experimental group, an effective rate of 96%, while 105 patients in the control group was considered effective in treatment, an effective rate of 91%, the effective rate in the experimental group was slightly higher than that in the control group, but there was no significant difference between the two groups (P value 0.182) (Tables 1 and 2) 0.28 days after the first treatment, we evaluated all patients through the Dix-Hallpike and Roll test and found that the effective rate was 100% in both the experimental group and the control group. We further divided the BPPV patients into pc-BPPV, hc-BPPV and hc-BPPV-cu subgroups, and analyzed the differences between the experimental group and the control group. For the pc-BPPV patients, the effective rate of the experimental group was higher than that of the control group (84%vs.71%)after the first treatment, although the difference did not achieve statistical significance (P = .078) (Table 3).After the second treatment, the effective rate of the experimental group reached 96%, in comparison with an effective rate of 84% of the control group, and statistical analysis showed significant improvement (P < .05) (Table 3). After the third treatment, the effective rate of the experimental group reached 100%, which was higher than 93% in the control group, but there was no significant difference between the two groups (Table 3). For the hc-BPPV patients, the effective rates of the first(81% vs.67%), second(92% vs.81%), and third(100% vs.96%) treatments were higher in the experimental group than those of the control group; and for the hc-BPPV-cu patients, the effective rates of the first(50% vs.23%), second(64% vs.38%) treatments were higher in the experimental group than those of the control group, while the effective rate of the third treatment(64% vs.69%)in the experimental group was slightly lower than that of the control group, the differences were not statistically significant, possibly due to low sample sizes (Tables 4 and 5). The patients who are not cured with the first repositioning treatment will be given MRI examination to rule out vertigo caused by other reasons, and they will be given oral betaestine to relieve the symptoms of vertigo. Therefore, the cost of BPPV patients includes the registration fee for each visit (RMB 15 yuan), the cost of each manual repositioning treatment (100 yuan) or BPPV diagnosis and treatment system repositioning treatment (300 yuan), the cost of medicine fee (betaestine 47 yuan/box), and MRI examination fee (597 yuan). The total costs of treatment in the experimental group (556.2 ± 486.0 yuan) were
4. Discussion Classical manual repositioning is an effective treatment and is recommended by the American Academy of Otolaryngology-Head and Neck Surgery's [5] guideline for posterior semicircular canal BPPV (Epley's maneuver), horizontal canal semicircular BPPV(Barbecue's maneuver) and cupulolithiasis of the horizontal canal BPPV(Gufoni's maneuver) [1,7].However, some patients are inconvenient in manual reposition because of limited physical mobility, obesity, severe cervical spondylosis [12], patients with refractory BPPV, etc. Recently, computer-controlled repositioning procedure has been applied to the treatment of BPPV, which has done a great help to patients who have difficulty in classical manual repositioning [6,8].In the study of Nakayama and Epley, it shows that the automated nystagmus-based repositioning is beneficial in BPPV treatment [9]. Xizheng et al. found that in 132 patients with pc-BPPV treated with computer-controlled repositioning, the effective rate was 81.8% [6], similar to our findings. Wang et al. compared the results of pc-BPPV patients treated with onetime automatic repositioning and one-time manual repositioning, and they found that the effective rates was slightly higher in the automatic repositioning group (90.90% vs. 86.96%) [10]. We found that 91 (79%) of 115 BPPV patients who were treated with BPPV diagnosis and treatment system had symptoms disappeared after the first treatment, compared with 74 (64%) of 115 BPPV patients treated with classical manual repositioning. After the second treatment, the effective rate of the patients in the BPPV diagnosis and treatment system group was 91%, while the effective rate of the manual repositioning group was 78%.After the third treatment, the effective rate was 96% in the experimental group, which was 91% in the control group, the effective rate in the experimental group was slightly higher than that in the control group, but there was no significant difference between the two groups. Furthermore, when the patients were sub-
Table 1 Comparison of clinical characteristics between experimental group and control group.
Age of onset Sex ratio(male: female) Side ratio(left:right)
The experimental group(n = 115)
The control group(n = 115)
P value
54(23–87) 1:1.95 1:0.98
53(23–84) 1:1.56 1:1.09
0.97 0.49 0.72
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Table 2 Comparison of efficacy between the experimental group and control group. No nystagmus
The experimental group(n = 115)
The control group(n = 115)
P value
First treatment; n(%) Second treatment; n(%) Third treatment; n(%)
91(79) 105(91) 110(96)
74(64) 90(78) 105(91)
< .05 < .05 .182
Table 3 Comparison of efficacy between experimental group and control group of pc-BPPV patients. No nystagmus
The experimental group(n = 75)
The control group(n = 75)
P value
First treatment; n(%) Second treatment; n(%) Third treatment; n(%)
63(84) 72(96) 75(100)
53(71) 63(84) 70(96)
.078 < .05 .058
Table 4 Comparison of efficacy between experimental group and control group of hc-BPPV patients. No nystagmus
The experimental group(n = 26)
The control group(n = 27)
P value
First treatment; n(%) Second treatment; n(%) Third treatment; n(%)
21(81) 24(92) 25(100)
18(67) 22(81) 25(96)
.352 .420 1.000
Table 5 Comparison of efficacy between experimental group and control group of hc-BPPV-cu patients. No nystagmus
The experimental group(n = 14)
The control group(n = 13)
P value
First treatment; n(%) Second treatment; n(%) Third treatment; n(%)
7(50) 9(64) 9(64)
3(23) 5(38) 9(69)
.236 .257 1.000
Table 6 Comparison of costs between experimental group and control group.
Repositioning treatment fee (RMB Yuan), mean ± SD Registration fee, mean ± SD Medicine fee (RMB Yuan), mean ± SD examination fee,(RMB Yuan), mean ± SD Total cost (RMB Yuan), mean ± SD
The experimental group(n = 115)
The control group(n = 115)
P value
401.7 ± 227.9 20.1 ± 11.4 9.8 ± 19.2 124.6 ± 243.7 556.2 ± 486.0
167.0 ± 105.7 25.0 ± 15.9 15.9 ± 22.3 202.5 ± 283.9 410.4 ± 417.9
< .05 < .05 < .05 < .05 < .05
repositioning treatment had a more stable long-term efficacy and a lower recurrence rate [8]. However, the sample sizes of these studies were small, and the efficacy of BPPV diagnosis and treatment system in the treatment of horizontal semicircular canal BPPV is still unclear. We evaluated the BPPV patients at 5 months of first repositioning, Five months after the first repositioning, the BPPV patients were evaluated and we found that the recurrence rate was close to previously reported. In our research, the recurrence rate in the experimental group was 20.7%, which was 26.4% in the control group, the BPPV diagnosis and treatment system had a lower recurrence rate, but there was no significant difference between the two groups. We further divided the BPPV patients into pc-BPPV, hc-BPPV and hc-BPPV-cu subgroups, for the pc-BPPV patients(19.2%vs.25%, P value 0.398), hc-BPPV patients (24%vs.26.9%, P value 0.811)and the hc-BPPV-cu patients(23.1% vs.33.3%, P value 0.673),the BPPV diagnosis and treatment system had a lower recurrence rate, but there were still no statistically significant difference between the two groups. In previous studies, there was a hypothesis that the fragments of otoliths maybe dispersed into the semicircular canal during the repositioning process, which required more than one repositioning maneuver to succeed. And the residual otolith may lead to an increase in the recurrence rate [15]. Our research found that the effective rate of the first and second repositioning
grouped to pc-BPPV, hc-BPPV and hc-BPPV-cu, we found that for pcBPPV patients, the effective rate after the second treatment was significantly higher in the experimental group than that of the control group. However, there was no significant difference between the two treatment groups for the hc-BPPV and the hc-BPPV-cu, which may be due to small sample sizes. We thus conclude that the BPPV diagnosis and treatment system has certain advantages compared with the manual repositioning. The former can move the otolith in the semicircular canal at a specific speed, rotation and precise plane, so that all patients could receive a standard repositioning treatment. At the same time, in the repositioning process, the nystagmus and the position of the semicircular canal can be observed and recorded in real time, so the accuracy of the repositioning is improved. In addition, the BPPV diagnosis and treatment system is highly safe, especially for patients with difficulty in manual repositioning treatment. Moreover, the eldest patients enrolled in this study were 87 years old, and he was well tolerated to the BPPV diagnosis and treatment system. BPPV is prone to recurrence, and the recurrence rate varies with time, ranging from 16% to 36% [13,14]. Liu et al. found that the 6month recurrence rate of pc-BPPV was 3% after automated mechanical repositioning treatment, while the 6-month recurrence rate was 8.9% in the manual repositioning group, and the automated mechanical
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Availability of data and materials
maneuver in the experimental group is higher than that in the experimental group. As mentioned before, the angle and speed during the manual maneuver are not as accurate as the machine maneuver, resulting in some otoliths remaining in the semicircular canal. This may also be the reason why the recurrence rate in the experimental group was slightly lower than that in the control group at the 5-month followup. In addition, patients with underlying diseases such as Meniere's disease, hypertension, migraine, and hyperlipidemia are also considered to be independent risk factors for BPPV recurrence [16].Due to so many factors involved in recurrence, the recurrence rates of the two groups did not reach a significant difference. At the same time, we calculated the cost of treatment for patients with BPPV. The total costs of treatment in the experimental group were slightly higher than the total costs of the control group. The main reason is that the repositioning treatment cost of experimental group is higher than that of the control group. However, other costs during the entire treatment process including registration fee, medicine fee and examination fee were lower in the experimental group than that of the control group. In addition, the prolonged duration of vertigo in the manual repositioning group will lead to longer time of lost working for patients than the machine repositioning group, which will increase the lost wages. However, due to the difference in work types of each patient, this cost cannot be accurately evaluated. However, this study has some limitations. First, this is a retrospective case-control study that provides only Level III evidence. Second, the sample size of hc-BPPV and hc-BPPV-cu was small, no significant difference was found between the two treatment groups. Third, although we observed a short-term efficacy after repositioning and a 5-month follow-up to determine the long-term efficacy, longer follow-up study is needed to determine the long-term efficacy of the BPPV diagnosis and treatment system. Fourth, previous studies showed that canal conversion is a common phenomenon occurring after repositioning treatment, in about 6–7% pc-BPPV patients treated with EM [1].It is worth to pay attention to the effect on canal conversion in future studies.
All data generated during this study are available from the corresponding author upon reasonable request. Authors' contributions YL contributed to manuscript writing and interpretation of the data. MC and LX contributed to acquisition of the data. YW and LZ contributed to interpretation of the data. XL contributed to the critical revision of the manuscript for intellectual content. All authors read and approved the final manuscript. Declaration of competing interest Nothing was received by we and our institution from the company that makes the BPPV Diagnosis and Treatment System used to test and treat patients referenced in our manuscript and study, and there are no conflicts of interest to be reported by the authors of this study. Acknowledgements This work was supported by the Natural Science Foundation of Zhejiang Province under Grant No. LQ19H090006; the Department of Health of Zhejiang Province under Grant No. 2019KY260. References [1] Kim JS, Zee DS. Clinical practice. Benign Paroxysmal Positional VertigoN Engl J Med 2014 Mar 20;370(12):1138–47. [2] Heidenreich KD. Images in clinical medicine. Benign paroxysmal positional vertigo. N Engl J Med. 2010 Jun 24;362(25):e70. [3] Parnes LS, Agrawal SK, Atlas J. Diagnosis and management of benign paroxysmalpositional vertigo (BPPV). CMAJ. 2003 Sep 30;169(7):681–93. [4] Bertholon P, Brandt T, Fife T, et al. Benign paroxysmal positional vertigo: Diagnostic criteria. J Vestib Res. 2015;25(3–4):105–17. [5] Bhattacharyya N, Gubbels SP, Schwartz SR, et al. Clinical practice guideline: benign paroxysmal positional vertigo (update) executive summary. Otolaryngology Head and Neck Surgery 2017;156(3):403–16. [6] Shan X, Peng X, Wang E. Efficacy of computer-controlled repositioning procedure for benign paroxysmal positional vertigo. Laryngoscope. 2015 Mar;125(3):715–9. [7] van Duijn JG, Isfordink LM, Nij Bijvank JA, et al. Rapid systematic review of the epley maneuver for treating posterior canal benign paroxysmal positional vertigo. Otolaryngol Head Neck Surg 2014 Jun;150(6):925–32. [8] Liu X, Treister R, Yan Y, et al. Automated mechanical repositioning treatment for posterior canal benign paroxysmal positional vertigo: a single-center experience and literature review. Eur Neurol 2017;78(5–6):240–6. [9] Nakayama M, Epley JM, et al. BPPV and variants: improved treatment results with automated, nystagmus-based repositioning. Otolaryngol. Head Neck Surg. 2005;133(1):107–12. [10] Wang N, Zhou H, Huang H, et al. Efficacy of SRM-IV vestibular function. diagnosis and treatment system in treating benign paroxysmal positional vertigo. Iran J Public Health. 2018 May;47(5):641–7. [11] Luryi AL, Lawrence J, Bojrab DI, et al. Recurrence in benign paroxysmal positional vertigo: a large, single-institution study. Otol Neurotol 2018 Jun;39(5):622–7. [12] Kollén L, Frändin K, Möller M, et al. Benign paroxysmal positional vertigo is a common cause of dizziness and unsteadiness in a large population of 75-year-olds. Aging Clin Exp Res 2012 Aug;24(4):317–23. [13] Song CI, Kang BC, Yoo MH, et al. Management of 210 patients with benign paroxysmal positional vertigo: AMC protocol and outcomes. Acta Otolaryngol. 2015 May;135(5):422–8. [14] Amor-dorado JC, Barreira-ferna MP, Aran-gonzalez I, et al. Particle repositioning maneuver versus Brandt-Daroff exercise for treatment of unilateral idiopathic BPPV of the posterior semicircular canal: a randomized prospective clinical trial with short- and long-term outcome. Otol Neurotol. 2012 Oct;33(8):1401–7. [15] Dispenza F, Mazzucco W, Mazzola S, et al. Observational study on risk factors determining residual dizziness after successful benign paroxysmal positional vertigo treatment: the role of subclinical BPPV. Acta Otorhinolaryngol Ital 2019 Oct;39(5):347–52. [16] Zhu CT, Zhao XQ, Ju Y, et al. Clinical characteristics and risk factors for the recurrence of benign paroxysmal positional vertigo. Front Neurol. 2019;13(10):1190.
5. Conclusions In summary, the BPPV diagnosis and treatment system is superior to the traditional manual repositioning in some aspects. Its long-term clinical efficacy and safety require further evaluation with a larger sample size. Abbreviations BPPV benign paroxysmal positional vertigo pc-BPPV Canalolithiasis of the posterior canal benign paroxysmal positional vertigo hc-PBBV Canalolithiasis of the horizontal canal benign paroxysmal positional vertigo hc-BPPV-cu Cupulolithiasis of the horizontal canal benign paroxysmal positional vertigo EM Epley's maneuver Compliance with ethical standards All procedures performed in this study involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
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