# 2014 Efficacy of Computer Controlled Repositioning Procedure for Benign

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The Laryngoscope
VC 2014 The American Laryngological,
Rhinological and Otological Society, Inc.
Efficacy of Computer-Controlled Repositioning Procedure for Benign
Paroxysmal Positional Vertigo
Xizheng Shan, MD; Xin Peng, MD; Entong Wang, MD, PhD
Objectives/Hypothesis: To evaluate the short-term efficacy of the computer-controlled canalith repositioning procedure
(CRP) for treatment of posterior canal benign paroxysmal positional vertigo (BPPV) compared with the current standard CRP.
Study Design: Prospective case series.
Methods: One hundred thirty-two patients diagnosed as having idiopathic posterior canal BPPV, with an age range of
28 to 86 years (mean 56 years), 47 men and 85 women, were treated with computer-controlled CRP mimicking the Epley
maneuver. Resolution of vertigo and nystagmus on the Dix-Hallpike test at 1-week follow-up after treatment was the main
outcome measure to assess the efficacy of treatment.
Results: At 1-week follow-up after treatment with computer-controlled CRP, 108 (81.8%) of 132 patients had complete
resolution of vertigo and nystagmus, nine (6.8%) had resolution of vertigo but presence of nystagmus, and 15 (11.4%) had
provoked vertigo and nystagmus on the Dix-Hallpike test. The 81.8% success rate was comparable to those who received cur-
rent standard CRP treatment in randomized controlled trials at about 80%. No significant adverse effects or complications
occurred in the patients treated with computer-controlled CRP, aside from two patients (1.5%) with conversion into lateral
canal BPPV.
Conclusions: Computer-controlled CRP is effective for the treatment of posterior canal BPPV, with a success rate similar
to those treated with the Epley maneuver, and is safe and easy to perform on patients.
Key Words: Benign paroxysmal positional vertigo, posterior semicircular canal, computer-controlled canalith reposition-
ing procedure, Epley maneuver, Dix-Hallpike test.
Level of Evidence: 4
Laryngoscope, 00:000–000, 2014
INTRODUCTION
Benign paroxysmal positional vertigo (BPPV) is a
common vestibular disorder characterized by repeated
episodes of positional vertigo produced by changes in
head position, with a lifetime prevalence of 2.4% in the
general population.1,2 Posterior canal BPPV (PC-BPPV)
accounts for about 90% of BPPV cases.3,4 Although
BPPV is a self-limiting disease with a favorable progno-
sis,5,6 persistent untreated BPPV may impact function,
health, and the quality of life of patients, and also may
leave patients, especially the elderly, with a high risk of
falls.7,8 Therefore, patients can benefit from prompt
treatment of BPPV.9
Although the etiology and pathophysiology of BPPV
have been not fully understood, canalolithiasis is widely
accepted as a main mechanism underlying BPPV.3 It is
believed that BPPV occurs when otoconia detach from
the macula of the utricle and enter the semicircular
canal, and the movement of free-floating canalith par-
ticles in the semicircular canal results in vertigo attacks
accompanied by nystagmus.3,10,11 Various canalith repo-
sitioning procedures (CRPs), which aim at moving the
free-floating particles in the semicircular canal back into
the utricle to relieve the vertigo symptom, have been
used for the treatment of BPPV.1,10–12 The Epley maneu-
ver (EM) as a CRP was first described by Epley in
1992.10 This maneuver has been used regularly to treat
BPPV, showing good efficacy in the treatment of PC-
BPPV, and success rates of more than 80% have been
reported in many randomized controlled trials
(RCTs).10,13–15 EM also is considered to be one of the
standard treatments for PC-BPPV and is recommended
as the first-line treatment of PC-BPPV in the current
clinical practice guidelines of the American Academy of
Otolaryngology–Head and Neck Surgery1 and the Ameri-
can Academy of Neurology.12
However, the use of EM is limited in some patients,
such as those with physical motion limitations and obe-
sity, and especially the elderly.1,16 Some therapeutic
devices have been developed to treat BPPV with promis-
ing treatment outcomes.17–21 In this prospective case-
series study, we evaluate the short-term efficacy of a
computer-controlled CRP (CCRP) mimicking EM for the
treatment of PC-BPPV.
From the Department of Otolaryngology–Head and Neck Surgery
(X.S., X.P., E.W.), General Hospital of Chinese People’s Armed Police
Forces, Beijing, China; and the Department of Otolaryngology–Head and
Neck Surgery (E.W.), Air Force General Hospital, Beijing, China.
Editor’s Note: This Manuscript was accepted for publication
September 15, 2014.
The authors have no funding, financial relationships, or conflicts
of interest to disclose.
Send correspondence to Entong Wang, MD, Department of Otolar-
yngology–Head and Neck Surgery, Air Force General Hospital, 30
Fucheng Road, Beijing 100142, China. E-mail: wang_entong@sina.com
DOI: 10.1002/lary.24961
Laryngoscope 00: Month 2014 Shan et al: Computer-Controlled Repositioning Procedure
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MATERIALS AND METHODS
Patients
This study was conducted at the Department of Otolaryn-
gology–Head Neck Surgery, General Hospital of Chinese Peo-
ple’s Armed Police Forces, Beijing, China from July 2010 to
June 2012 and was approved by the hospital ethics committee.
A total of 138 consecutive patients diagnosed as having PC-
BPPV were enrolled in the study. Informed consent was
obtained from each patient. All patients underwent standard
clinical examinations, diagnostic tests, and evaluation before
treatment with CCRP. The inclusion criteria were as follows:
history and symptoms compatible with idiopathic BPPV and
diagnosis of unilateral PC-BPPV by the Dix-Hallpike test
(DHT),1 BPPV occurring within 1 month before presentation,
and BPPV not treated previously with CRP or vestibular sup-
pressant medications. Patients were excluded when they had
other variants of BPPV, other forms of peripheral or central ver-
tigo, sudden sensorineural hearing loss, vestibular neuritis or
labyrinthitis, Meniere’s disease, migraine, superior canal dehis-
cence syndrome, vestibular neuroma, severe central nervous
system disorders, and severe cardiovascular diseases.
Diagnosis and Treatment of PC-BPPV
PC-BPPV was diagnosed according to the criteria of the
clinical practice guidelines of the American Academy of Otolaryn-
gology–Head and Neck Surgery1 as patient-reported history of
repeated episodes of vertigo with changes in head position and
demonstrated characteristic vertigo and nystagmus provoked by
the DHT. The performance of the DHT was reproduced by the
diagnosis and therapy system for BPPV (Byrons Medical Science
& Technique Inc., Jinan, China) (Fig. 1).22 All enrolled patients,
according to their affected posterior canals identified by the
DHT, were promptly treated with initial CCRP. At 24 hours after
the initial CCRP, the patients who still presented with positional
vertigo were given a second CCRP. The CCRP, which mimicked a
standard EM as described in two guidelines,1,12 was also per-
formed by the diagnosis and therapy system for BPPV (Fig. 1).
In the study, all movements of the patients during the mimicked
DHT or EM were performed at 90� per second.
Any adverse effects or complications, if present, were
recorded, and the patients were promptly treated. No medica-
tion was routinely administered before or after CCRP. No pos-
tural restrictions after CCRP were advised to the patients,
because evidence-based studies have shown postural restric-
tions after CRP do not show significant benefits.23,24
Follow-up and Main Outcome Measures
Patients were followed up at 1 week after initial or second
CCRP to assess the resolution of vertigo and nystagmus on the
DHT. The resolution of vertigo alone or both vertigo and nystag-
mus on the DHT were used as the main outcome measures to
evaluate the effectiveness of CCRP for treatment of PC-BPPV.
When absentof both provoked vertigo and nystagmus on the
DHT, the patient was considered as having complete resolution of
PC-BPPV. When a patient exhibited canal conversion after the ini-
tial or second CCRP, the patient would undergo further treatment
with corresponding CRP based on the affected canal, but the
patient, even with a successful treatment outcome in previous
CCRP for PC-BPPV, or in following CRP for other types of BPPV,
was not included in the efficacy analysis of CCRP for PC-BPPV.
For the CCRP patients who failed at 1-week follow-up, they would
be followed up further, reevaluated, and given individual treat-
ments. Subsequent treatment results were not included in the
analysis for short-term efficacy of CCRP in this study.
RESULTS
A total of 138 patients, diagnosed as having unilat-
eral PC-BPPV and treated with CCRP, were initially
Fig. 1. The diagnosis and therapy system for BPPV. This system mainly consists of a computer-controlled rotary chair (left) and a work sta-
tion (right). Under control of the computer at the work station, the chair can be rotated on multiple planes at specific speeds at any
degrees; thus, various diagnostic and repositioning maneuvers for BPPV can be performed by this system. Patient wears eye goggles con-
nected with the camera that transfer the patient’s nystagmus signals wirelessly to the computer. The nystagmus video, dynamic nystagmus
curve, semicircular canal orientation, and chair position during the Dix-Hallpike test or repositioning maneuver can be displayed in real time
on the monitor, and nystagmus, if present, can be recorded, analyzed, and documented by the computer. [Color figure can be viewed in
the online issue, which is available at www.laryngoscope.com.]
Laryngoscope 00: Month 2014 Shan et al: Computer-Controlled Repositioning Procedure
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enrolled in this study. Three patients were lost for
follow-up, one patient was excluded due to sudden sen-
sorineural hearing loss, and two patients were excluded
due to the occurrence of canal conversion during CCRP.
Thus, 132 patients were included in the analysis for
evaluating the short-term efficacy of CCRP. The 132
patients were aged from 28 to 86 years (56.16 9.2
years), and among them 85 (64.4%) were female and 47
(35.6%) were male, with a female/male ratio of 1.81. The
duration of BPPV before presentation was 1 to 30 days
(13.868.7 days), with a median of 12 days.
All 132 patients received initial CCRP, and at 24
hours after initial CCRP, 48 (36.4%) patients showed
resolution of vertigo, whereas the other 84 (63.6%)
patients still presented with positional vertigo and were
given a second CCRP. An average of 1.64 CCRPs were
applied to each patient by the 1-week follow-up. With
the DHT at the 1-week follow-up after treatment with
CCRP, three treatment outcomes were obtained: 108
(81.8%) of 132 patients had a complete resolution (no
presence of vertigo or nystagmus), nine (6.8%)patients
had subclinical BPPV (absence of vertigo but presence of
nystagmus), and 15 patients (11.4) were considered as
having treatment failure (presence of both vertigo and
nystagmus). When the resolution of vertigo was the
main outcome measure, according to absence or presence
of provoked vertigo regardless of nystagmus on the
DHT, a success rate of 88.6% (117/132) was obtained at
1-week follow-up. If the presence of objective nystagmus
on the DHT was showed, whether or not vertigo was
present, a positive nystagmus rate of 18.2% (24/132) was
achieved at the 1-week follow-up.
CCRP was tolerated well by all patients, and no
serious side effects from the use of CCRP were found,
aside from discomfort and transient nausea reported in
several patients. Two patients (1.5%) were found with
canal conversion or canal switch to lateral canal; one
occurred after initial CCRP and the other after the sec-
ond CCRP. They were treated successfully by barbecue
roll maneuver with resolution of symptoms subse-
quently. None of the 132 patients experienced conversion
to superior canal BPPV during CCRP.
DISCUSSION
EM is a highly effective treatment for PC-BPPV,
which is supported by evidence-based clinical practice
guidelines,1,12 systematic reviews, and meta-analy-
ses.9,25–29 However, some patients are difficult to treat
with classic manual EM. In recent years, several thera-
peutic repositioning devices have been developed to treat
BPPV, and some studies have shown that the devices can
successfully treat BPPV including difficult-to-treat
BPPV.17–22 Lempert et al.’s study showed that seven
(63.6%) of 11 patients with PC-BPPV had resolution of
vertigo symptoms after EM was performed with a three-
dimensional flight simulator.17 In the study of Nakayama
and Epley, a power-driven multiaxial repositioning chair
was used for treatment of several BPPV variants, and
good treatment outcomes were showed in their study.18 Li
and Epley also used the multiaxial positioning device to
treat PC-BPPV using a 360� maneuver, with a good sub-
jective improvement rate (90%) after one treatment and
good resolution rate (97%) of both vertigo and nystagmus
after a maximum of three treatment sessions in 31
patients, including in the elderly over 90 years old.19
Shan et al. used a similar positioning device to treat
BPPV, with promising treatment outcomes.20 Recently, a
report showed that a 96-year-old patient afflicted with
PC-BPPV was cured successfully by EM performed with
a motorized turntable.21 The diagnosis and therapy sys-
tem for BPPV used in the present study has been used in
our clinic since 2009, showing good efficacy for the diag-
nosis and treatment of BPPV.22 In the present study, we
evaluated the short-term efficacy of CCRP for the treat-
ment of PC-BPPV. In the short term, typically at 1 week,
CRP is very effective at providing symptom resolution for
PC-BPPV.1 It is thought that the absence of vertigo may
be the best indicator of success for CRP, 9,30 and many tri-
als also report the conversion from positive to negative
DHT after EM as a secondary outcome,9 similar to
reported rates of symptom resolution.26 Thus, the resolu-
tion of vertigo or nystagmus on the DHT may be eval-
uated separately due to the possible presence of
subclinical BPPV.1,30,31 Our study showed that 117
(88.6%) of 132 patients with idiopathic PC-BPPV had
resolution of vertigo, and 108 (81.8%) patients had resolu-
tion of both vertigo and nystagmus on the DHT at the 1-
week follow-up after CCRP. CCRP may allow us to obtain
a good success rate similar to those received by EM in
most studies. A conversion rate of 81.8% to a negative
DHT may also be comparable to the rates of 66% to 89%
reported in an RCT.26 Another RCT showed that 80.5%
(33/41) of EM-treated patients with unilateral idiopathic
PC-BPPV had resolution of both vertigo and nystagmus
on the DHT at day 7 after EM.14 In another RCT, the
resolution of both vertigo and nystagmus was obtained in
86.4% (19/22) of patients with PC-BPPV on the DHT at 1
week after EM.13 Our study indicates that CCRP may be
comparable to EM in therapeutic efficiency. Studies sug-
gest that a few BPPV patients may demonstrate so-called
subclinical BPPV after CRP, or absence of provoked ver-
tigo but presence of nystagmus on the DHT.1,30,32,33 In
our study, nine (6.8%) of the 132 patients presented with
subclinical PC-BPPV by 1-week follow-up on the DHT. In
addition, BPPV as a self-limiting disorder may resolve
spontaneously.1 However, a previous study showed 30% of
patients with PC-BPPV demonstrated the spontaneous
disappearance of vertigo within 7 days, with an average
of 396 47 days from the onset to remission of the ver-
tigo,5 and a recent RCT showed that only eight (36%)
patients of 22 sham-treated PC-BPPV patients with dura-
tion of at least 1 month demonstrated resolution of BPPV
on the DHT at 1 month after treatment.15 Recently, a sys-
tematic review also showed that based on theanalysis of
pooled data, only six (8%) of 77 patients and 34 (36%) of
94 patients obtained spontaneous resolution of vertigo at
1-week and at 1 month, respectively, after watchful wait-
ing.9 Thus, the resolution rate (88.6%) of vertigo symp-
toms at 1 week after CCRP in our study could not be
explained completely by the spontaneous resolution of
vertigo.
Laryngoscope 00: Month 2014 Shan et al: Computer-Controlled Repositioning Procedure
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With respect to adverse effects and complications,
no serious side effects or complications were found in
the CCRP-treated patients aside from two patients
(1.5%) with canal conversion to the lateral canal after
CCRP. Canal conversion is a well-known phenomenon
that occurs with CRP and is considered a complication
of CRP.1,34–37 Canal conversion occurs in about 6% to 7%
of PC-BPPV treated with EM.38,39 A previous study
showed that among 85 patients with PC-BPPV treated
by EM, three patients (3.5%) had the switch to the lat-
eral canal and two patients (2.4%) to the anterior
canal.38 In another study of 564 EM-treated patients
with PC-BPPV, 13 (2.3%) patients had the switch to
anterior canal BPPV.37 Recently, a study showed that of
44 patients with PC-BPPV treated by a single CRP,
seven (16%) patients demonstrated canal conversion to
the lateral canal.36 In our study, the incidence of canal
conversion was low (1.5%), and no patient experienced
conversion to the superior canal BPPV after CCRP.
Compared with manual EM, CCRP offers some
advantages. First, CCRP may completely mimic the per-
formance of EM, and the patient may be moved on an
accurate plane at specific speeds and degrees of rotation.
All CCRP-treated patients receive a precise and uni-
formed repositioning maneuver. The nystagmus of
patients, orientation of semicircular canals, and the posi-
tion of the chair during CRP can be monitored in real
time. Second, CCRP is a safe maneuver and has good
applicability. In some patients with comorbid diseases,
body movement limitations, or obesity, those conditions
may render them unsuitable for manual EM, especially
the elderly,1,16,40 but difficult-to-treat BPPV can be
treated by CCRP. Third, the treatment of BPPV is
involved in multiple clinical disciplines, and there are
certain differences in EM performed by different physi-
cians, whereas standardized CCRP is a repeatable and
comparable maneuver. CCRP is easy to perform by a
physician alone and takes less time.
CONCLUSION
CCRP is an effective treatment for PC-BPPV and
offers excellent short-term results, comparable to cur-
rent standard repositioning maneuvers for PC-BPPV.
Compared with manual EM, CCRP allows a physician to
perform CRP alone, without needing help from an assist-
ant, requires less time for the repositioning maneuver,
and it is well tolerated by patients, especially the elderly.
Our study supports the use of CCRP as a treatment
choice for PC-BPPV, although manual EM still may be
considered as a standard treatment.
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