10.14639/0392-100X-suppl.1-43-2023-08
Benign baroxysmal positional vertigo (BPPV) represents the most common peripheral vestibular dysfunction encountered in clinical practice. Although canalith repositioning procedures (CRPs) are a relatively successful treatment for BPPV, many patients suffer from recurrences. Several studies have demonstrated that various pathological conditions (diabetes, hypertension, endolymphatic hydrops, low vitamin D levels) as well as delayed BPPV treatment using CRP, multiple canal involvement may be associated with recurrence of BPPV. We evaluated the history of 1,428 patients (558 males and 870 females, age range 10-92 years) suffering from BPPV. Of 1,428 cases, 820 (77%) did not relapse in the following 20 years. Mean age and gender did not differ significantly between groups with and without recurrence. Regarding risk factors for BPPV recurrence, age, female gender, migraine, hypertension, diabetes mellitus, hyperlipidaemia, osteoporosis, vascular diseases, and vitamin D deficiency may be associated with recurrent BPPV and should be kept in mind. Osteoporosis, vitamin D deficiency as well as thyroid dysfunction should be evaluated in postmenopausal women. Treatment of these comorbidities may help to reduce the risk of BPPV recurrence.
text/xml
1827-675X
2610
en
Mauro Gufoni
http://creativecommons.org/licenses/by-nc-nd/4.0
ACTA Otorhinolaryngologica Italica
risk factors
Recurring benign paroxysmal positional vertigo after successful canalith repositioning manoeuvers
Text.Serial.Journal
https://www.actaitalica.it/
43
Annual congress report
2023-04-21
2023-04-20
2023-04-28
2023-04-28
S61-S66
1
Mauro Gufoni
2023/04/21
10.14639/0392-100X-suppl.1-43-2023-08
S61
Department of Medicine and Surgery, ENT Section, Pisa University Hospital, Pisa, Italy
1827-675X
risk factors
S66
Recurring benign paroxysmal positional vertigo after successful canalith repositioning manoeuvers
https://www.actaitalica.it/article/download/2610/945
43
ACTA OTORHINOLARYNGOLOGICA ITALICA 2023;43(SUPPL.1):S61-S66; doi: 10.14639/0392-100X-suppl.1-43-2023-08




Otology section


Recurring benign paroxysmal positional vertigo after
successful canalith repositioning manoeuvers
Le recidive della vertigine parossistica posizionale benigna dopo il successo
della terapia con manovre di riposizionamento otolitico
Augusto Pietro Casani, Mauro Gufoni
Department of Medicine and Surgery, ENT Section, Pisa University Hospital, Pisa, Italy


SUMMARY
Benign baroxysmal positional vertigo (BPPV) represents the most common peripheral
vestibular dysfunction encountered in clinical practice. Although canalith repositioning
procedures (CRPs) are a relatively successful treatment for BPPV, many patients suffer
from recurrences. Several studies have demonstrated that various pathological conditions
(diabetes, hypertension, endolymphatic hydrops, low vitamin D levels) as well as delayed
BPPV treatment using CRP, multiple canal involvement may be associated with recurrence
of BPPV. We evaluated the history of 1,428 patients (558 males and 870 females, age range
10-92 years) suffering from BPPV. Of 1,428 cases, 820 (77%) did not relapse in the fol-
lowing 20 years. Mean age and gender did not differ significantly between groups with
and without recurrence. Regarding risk factors for BPPV recurrence, age, female gender,
migraine, hypertension, diabetes mellitus, hyperlipidaemia, osteoporosis, vascular diseases,
and vitamin D deficiency may be associated with recurrent BPPV and should be kept in
mind. Osteoporosis, vitamin D deficiency as well as thyroid dysfunction should be evalu-
ated in postmenopausal women. Treatment of these comorbidities may help to reduce the
risk of BPPV recurrence.
KEY WORDS: dizziness, vertigo, benign paroxysmal positional vertigo, risk factors
                                                                                                 Received: December 12, 2022
RIASSUNTO                                                                                        Accepted: January 8, 2023
Sono stati presi in considerazione 1.428 soggetti osservati, dal primo gennaio 1996 al 31
dicembre 2000, con diagnosi di vertigine parossistica posizionale. Scopo del lavoro era          Correspondence
di verificare il numero di recidive manifestatesi nei venti anni successivi al primo episo-      Augusto Pietro Casani
dio vertiginoso confermato clinicamente. A questo scopo sono state controllate cartelle          Department of Medicine and Surgery, ENT Section,
cliniche di ogni paziente. Su 1.428 casi (corrispondenti a 1.067 pazienti alcuni dei quali       Pisa University Hospital, via Paradisa 2, 56124
avevano avuto più di un episodio) diagnosticati quasi il 77% dei pazienti (820/1.067) non        Pisa, Italy
è recidivato e meno del 17% dei pazienti (180/1.067) ha presentato una sola ripresa della        Tel. +39 050997499
sintomatologia vertiginosa. Inoltre solo in 67 casi su 1.067 (poco più del 6% dei casi) si       E-mail: augusto.casani@unipi.it
assiste a più di due recidive. La vertigine parossistica posizionale da canalolitiasi è una
affezione che tende a recidivare. Le reali recidive però sembrano meno di quelle che ci si         How to cite this article: Casani AP, Gufoni
può aspettare e sembra che una profilassi farmacologica sia consigliabile solo nei pazienti        M. Recurring benign paroxysmal positional
con tendenza ad un numero elevato di recidive od in pazienti da valutare caso per caso.            vertigo after successful canalith reposition-
Nella quasi totalità dei pazienti sembra preferibile alla profilassi farmacologica l’esecuzio-     ing manoeuvers. Acta Otorhinolaryngol Ital
ne delle manovre al momento della recidiva.                                                        2023;43(SUPPL.1):S61-S66.         https://doi.
                                                                                                   org/10.14639/0392-100X-suppl.1-43-2023-08
PAROLE CHIAVE: vertigine parossistica posizionale benigna, dizziness, recidiva, fattori
di rischio                                                                                       © Società Italiana di Otorinolaringoiatria
                                                                                                 e Chirurgia Cervico-Facciale


                                                                                                                OPEN ACCESS
Introduction                                                                                     This is an open access article distributed in accordance with
                                                                                                 the CC-BY-NC-ND (Creative Commons Attribution-Non-
Benign paroxysmal positional vertigo (BPPV) is the most common peripheral                        Commercial-NoDerivatives 4.0 International) license. The
vestibular dysfunction encountered in clinical practice, with a reported 1-year                  article can be used by giving appropriate credit and mentio-
                                                                                                 ning the license, but only for non-commercial purposes and
prevalence of 1.6% and a lifetime prevalence of 2.4% 1. BPPV is characterised by                 only in the original version. For further information: https://
recurrent episodes of vertigo with corresponding nystagmus, generally provoked                   creativecommons.org/licenses/by-nc-nd/4.0/deed.en




                                                                                                                                                         S61
A.P. Casani, M. Gufoni




by changes in head position. BPPV accounts for 25% of all            2. the patient goes to another healthcare facility;
cases of vertigo that come to the attention of clinicians and        3. the patient, after many years, is no longer able to return
can affect all ages, although it can be underdiagnosed in the            (more serious illnesses, disability, death, etc.).
elderly; the most affected age group is the fifth and sixth dec-     Point 1 seems very unlikely, and anyone familiar with this
ade 2. Women are affected twice as often as men 3. Some stud-        type of vertigo can agree on this point.
ies also found that patients with BPPV were at increased risk        Point 2 is possible but unlikely, since the patient has a pref-
of falls, fractures, hypertension and dementia 4-7. In addition,     erential access route to the facility (no waiting lists, limited
BPPV may cause physical and psychological distress dur-              or no expense). Experience tells us that the reverse case is
ing episodes of vertigo. Therefore, BPPV severely decreases          much more likely, i.e. that patients return even if they do
patients’ quality of life and impairs the performance of daily       not have a recurrence of BPPV.
activities 8. BPPV is thought to be the clinical expression of       Point 3 obviously cannot be excluded, but it is a bias that
otoconial particles of utricular origin migrating into the lumen     is impossible to eliminate over long follow-up periods. The
of a semicircular canal. For reasons of spatial arrangement,         case of death is not taken into consideration because the
the gravitational field favours dislocation in the posterior and     study evaluates recurrences during life.
lateral semicircular canal 2,3. The possibility of migration into    Finally, the repeated access retrospective study seems the
the anterior canal 9, which is rare and could be confused with       most reliable way to get an idea of long-term relapses,
a posterior canalolithiasis with a non-ampullary location 10,        which is what was adopted.
is more difficult and still debated. In most patients suffering      In the period from January 1996 - December 2000 we evaluat-
from BPPV, there is no evident cause. In some cases, BPPV            ed 6,104 patients (2,622 males and 3,482 females) complain-
resolves spontaneously within a few weeks 11 with a slow and         ing of vertigo and/or dizziness. From this group of patients,
gradual resolution of vertigo 12. Post-traumatic causes of BP-       we selected 1,067 subjects affected by BPPV (558 males and
PV include whiplash injury, high-impact exercise and surgical        870 females) who were followed for 20 years. Clinical data
procedures 3,13. Other conditions predisposing to the detach-        were obtained from our records. All patients found in our
ment of otoconia from utricular maculae are viral, ischaemic,        clinical records were included if they fulfilled criteria for sin-
or hydropic disorders involving the inner ear 3,14,15, migraine 16   gle or multiple canal BPPV 2,3. In 1,119 (78.4%) cases a pos-
and a prolonged recumbent position 17. Other risk factors for        terior semicircular canal BPPV was found, and 309 (21.6%)
BPPV include female gender, age over 60 years, osteoporosis,         patients resulted to be affected by horizontal semicircular
hypertension and non-apnoea sleep disorders 2,3,18-21.               canal BPPV (in 286 patients, 92.6%, ageotropic and in 34,
Currently, although canalith repositioning procedures (CRPs)         7.4%, apogeotropic). All patients were treated with a Se-
are a relatively successful treatment for BPPV 2,3, many pa-         mont or Epley manoeuver (in case of posterior semicircular
tients suffer from repeated episodes of BPPV, with a reported        canal BPPV) or Gufoni manoeuver followed by the Forced
recurrence rate of approximately 50% during 10-year follow-          Prolonged Position (in case of horizontal semicircular canal
up 22,23. Similarly, it was reported that 10% to 18% patients        BPPV). Patients were instructed to return to our vestibular
relapse during a 1-year follow-up period 24. In addition, a re-      unit in the event of a recurrence of symptoms to control for
cent meta-analysis suggested that many risk factors related to       the presence of BPPV and to repeat the CRP.
the recurrence of BPPV may also be risk factors for its occur-
rence 25. The frequent recurrence of BPPV may cause great            Results
inconvenience in the daily life of BPPV patients. The aim of
this paper is to evaluate the long-term tendency for recurrence      Of 1,067 patients diagnosed with BPPV, 820 (76.85%)
of BPPV.                                                             did not show any recurrence in the following 20 years,
                                                                     180 (16.87%) patients had one relapse, 41 (3.84%) had
                                                                     two relapses, 16 (1.5%) had three relapses, 4 patients 4
Materials and methods                                                (0.37%) relapses, 4 (0.37%) patients five relapses, one
For short-term evaluation (weeks), patients could undergo            patient (0.09%) and six relapses. In one patient, 9 recur-
direct clinical follow-up, but for our purposes this is not          rences after the first episode were seen in the following
sufficient. Considering that our patients could directly ad-         20 years (Fig. 1). Furthermore, we evaluated if age and
dress our centre in cases of recurrence, we choose to ret-           sex influenced the incidence of recurrence of BPPV. Hav-
rospectively examine how many times patients came to us              ing in mind the number of recurrences, we evaluated the
because for a new onset of positional vertigo.                       mean age of patients (Fig. 2) and the relative differences
This method does not exclude various critical issues:                between males and females (Fig. 3). There were no sig-
1. the patient does not return to control visits;                    nificant differences in either case.



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Figure 1. Distribution of the number of recurrencies in 1,067 patients diag-           Figure 2. Mean age of the patients affected by recurrent BPPV distributed by
nosed with BPPV during 1996-2020. The majority of patients showed no more              the number of recurrences (r: recurrences). The patients with more than 4 re-
than 2 recurrences in the 20 years following the onset of the first episode of BPPV.   currences showed an age > 65 years, with no statistical significance.

Discussion
Two stages are required for the paroxysmal positional ver-
tigo to be triggered:
1. the detachment of otoliths in a quantity able to induce
    positional vertigo;
2. their migration within a semicircular canal.
Each of these two moments is necessary: if the detached oto-
liths will not migrate in the semicircular canal, we can specu-
late about the existence of an abnormal macular activity lead-
ing to a disequilibrium, but not causing the positional vertigo.
Although it was revealed that more than 95% of cases can
be cured by a canalith repositioning manoeuver (CRM),
in some cases BPPV resolves spontaneously within a few
weeks 11 with a slow and gradual resolution of vertigo prob-                           Figure 3. Sex distribution based on of the number of recurrences of BPPV (r:
ably due to a progressive dissolution (quickly or slowly,                              recurrences). Although recurrences are more frequent in women in any group,
                                                                                       no significant difference was found.
depending on the state of aggregation) in the endolymph
of the dislodged otoliths 12. Consequently, the nystagmus                              isode (no more than 6 to 8 weeks) given the time assumed for
evoked by the positioning manoeuver tends to decrease in                               reabsorption of the fragments and the recurrence occurs in the
intensity and the symptoms can change from a true rotatory                             same ear even if not in the same semicircular canal. Usually
positional vertigo to a sense of imbalance and instability                             the patient reports that the second episode is less intense than
evoked by assuming the provocative position.                                           the first. This is reasonable if we consider that resorption has
Recurrent BPPV was defined as the reappearance of par-                                 occurred in the meantime, which made the fragments “lighter”
oxysmal positional nystagmus after at least 2 weeks from                               and therefore giving less intense vertigo (Fig. 4).
the execution of CRM: in our opinion, it is necessary to be                            The probability of fragments moving into a critical zone must
aware that recurrences can be of two types:                                            be directly proportional to the available otolithic mass: the
1. the detached otoliths return into the utricule (spontane-                           greater the size of the mass, the greater the probability that
    ously or by the effect of CRM) where they may remain                               a portion will move over time causing a recurrence of BPPV.
    for a period undergoing dissolution; on the contrary, this                         Consequently:
    material can again move to the semicircular canal. In the
    latter case this is not considered as a recurrence, because
    the actual symptom is caused by the same debris;
2. caused by a new detachment of otoliths.
In the first case, the recurrence occurs shortly after the first ep-                   the quantity Q of otolithic fragments available for migra-



                                                                                                                                                              S63
A.P. Casani, M. Gufoni




Figure 4. The recurrence of BPPV is caused by the same (large) debris return-          Figure 5. The recurrence of BPPV is influenced by the dimension of the oto-
ing to the semicircular canal (s.c.); in this case, the positional attack of vertigo   lithic mass (Q). The likelihood of recurrence is greater as the mass increases in
occurs on the same side, no more than 6 to 8 weeks after the first episode (A-B).      size, which however decreases over time based on mobilisation (spontaneous or
If the same debris re-enters the semicircular canal it induces less intense symp-      induced by CRM). The higher k (the variable influencing the reabsorption time)
toms because the mass became smaller due to its partial reabsorption (C-D).            the more the patient moves and the sooner the patient recovers.

tion varies (decreases) as a function of time and is propor-                           three episodes of paroxysmal positional vertigo in 20 years. On
tional, according to the constant k, to the residual mass.                             the other hand, there are only isolated cases of patients showing
Solving the differential equation:                                                     a great tendency to suffer from recurrent BPPV: in one case 10
                                                                                       recurrences of vertigo were observed, and in 5 cases at least 6
                                                                                       episodes. These patients experienced a great decrease in qual-
                                                                                       ity of life, especially taking in consideration that BPPV does
The quantity Q of otolithic fragments available for migration                          not only affect the elderly, but often also during active life. Our
at time t is dependent on the initial available mass Q0 of free                        results are in line with a recent study in which the recurrence
otoliths, Q(t) is the quantity of fragments present at time t, k is                    rate was 22% at 5 years after initial treatment and about 70% of
a variable that influences the resorption time and thus in prac-                       recurred patients had a relapse within 1 year 33.
tice the duration of the disease: the higher the k coefficient (the                    Regarding the evaluation of risk factors for BPPV recurrence,
patient moves, or exercises, or is less blocked by vertigo), the                       two recent meta-analyses indicated that age (> 65 years), fe-
sooner the patient becomes symptom-free (Fig. 5).                                      male gender, migraine, hypertension, diabetes mellitus, hy-
Several studies have demonstrated that various pathological                            perlipidaemia, osteoporosis and vitamin D deficiency may be
conditions (diabetes, hypertension, endolymphatic hydrops,                             associated with recurrent BPPV 25,34. Vascular damage, ischae-
low vitamin D levels) as well as delayed BPPV treatment us-                            mia, or atherosclerosis induced by vascular comorbidities may
ing CRM and multiple canal involvement may be associated                               cause displacement or degenerative changes of otoconia 35,36,
with the recurrence of BPPV 25-29. Furthermore, the recurrence                         which may explain why vascular comorbidities have adverse
of BPPV is more frequent in patients affected by multiple,                             effects on BPPV 19. The pooled results of the above-mentioned
associated diseases 30. However, the evidence reported in the                          meta-analyses showed that hypertension, diabetes mellitus
literature is conflicting. For example, some studies showed no                         and hyperlipidaemia may increase the risk of BPPV recur-
correlation between gender, age and recurrent BPPV 31, while                           rence. Therefore, vascular comorbidities should be actively
other studies reported that age and gender are related to recur-                       treated to eliminate potentially vascular risk factors for BPPV
rent BPPV 1,32. In our experience, we did not find a significant                       recurrence, which may help reduce the recurrence rate and
increase of the recurrence of BPPV in older patients, while re-                        improve te prognosis. Unfortunately, there is no consensus in
garding sex we noticed a higher incidence in females, without                          the literature about the relevance of risk factors involved in the
however reaching statistical significance.                                             recurrence of BPPV. For example, a large single-institution
BPPV tends to recur over time, but our data seem to indicate                           study of recurrence in BPPV indicated female sex and history
that the chances of a recurrent episode are less frequent than                         of previous BPPV as risk factors associated with an increased
reported in the literature 22,23. Less than half of patients showed                    rate of recurrence, while no association with Menière’s dis-
a recurrence and more than two-thirds of patients experienced                          ease, diabetes mellitus, or traumatic aetiology was found 37.
only one episode of recurrence over 20 years. In our series, on-                       Regarding vitamin D deficiency, a previous meta-analysis
ly 26 of 1,067 patients (just over 2%) presented with more than                        demonstrated that it was an independent risk factor for BPPV



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                                                                                                       Recurring benign paroxysmal positional vertigo




occurrence and recurrence 38; this correlation may be explained       review about recurring BPPV. A large prospective multicentre
by the fact that vitamin D deficiency may disrupt calcium me-         study should be carried out to better evaluate risk factors that
tabolism in the inner lymphatic fluid and bone metabolism,            can potentially affect the recurrence of BPPV.
leading to osteoporosis and increasing the risk of BPPV 39. A
recent multicentric study suggested that oral nutritional sup-        Conflict of interest statement
plementation with vitamin D3 may prevent relapses in patients         The authors declare no conflict of interest.
suffering from a high number of recurrent episodes of BPPV 40.
Further large-scale studies are necessary to establish the role of    Funding
vitamin D supplementation in prevention of BPPV recurrence.           This research did not receive any specific grant from funding
Migraine is reported to be a risk factor for BPPV recur-              agencies in the public, commercial, or not-for-profit sectors.
rence 41,42. Migraine and BPPV are among the most frequently
encountered diseases in otoneurological clinics. It is likely that    Author contributions
patients with migraine have recurrent damage to the inner ear         APC: conceptualisation, writing – review and editing and
(due to vasospasm or some other mechanism) that predisposes           supervision; MG, APC: methodology, formal analysis, in-
them to recurrent episodes of BPPV. However, a recent meta-           vestigation, writing – original draft preparation.
analysis found no significant association between migraine            All authors have read and agreed to the published version
and the recurrence of BPPV, probably due to significant het-          of the manuscript.
erogeneity and the small number of included studies 25,34. Re-
cently, the association between hypothyroidism and BPPV               Ethical consideration
has been investigated 43,44. Another study demonstrated that          Due to the retrospective nature of this observational study (not
patients with hypothyroidism treated with hormone replace-            considered as part of a research project) it did not require ap-
ment therapy have an increased risk of BPPV recurrence,               provals of Ethics Committee. Furthermore, the study does not
which is particularly strong for patients with Hashimoto’s thy-       include new invasive or experimental procedures or diagnos-
roiditis and positive thyroid antibodies, suggesting an associa-      tic protocol; all patients underwent routinely performed tests
tion between autoimmunity and recurrent BPPV, and thus the            only, according to national guidelines. Informed consent was
importance of investigating thyroid dysfunction 45.                   obtained from all participants and the study was performed in
                                                                      accordance with the Declaration of Helsinki.
Conclusions
In case of recurrent BPPV, we recommend that careful medi-            References
cal history should be taken especially regarding cardiovascular       1
                                                                          Von Brevern M, Radtke A, Lezius F, et al. Epidemiology of benign paroxys-
comorbidities (hyperlipidaemia and hypertension), as well as              mal positional vertigo: a population-based study. J Neurol Neurosurg Psych
                                                                          2007;78:710-715. https://doi.org/10.1136/jnnp.2006.10042
the presence of diabetes mellitus. Good control of these comor-       2
                                                                          Kim JS, Zee DS. Clinical practice. Benign paroxysmal positional vertigo. N
bidities should always be maintained in these patients. In addi-          Engl J Med 2014;370:1138-1147. https://doi.org/10.1056/NEJMcp1309481
tion, osteoporosis, and vitamin D deficiency as well as thyroid       3
                                                                          Nuti D, Zee DS, Mandalà M. Benign paroxysmal positional vertigo:
dysfunction should be evaluated especially in postmenopausal              what we do and do not know. Semin Neurol 2020;40:49-58. https://doi.
                                                                          org/10.1055/s-0039-3402733
women with recurrent episodes of BPPV 46. Therefore, treat-           4
                                                                          Kao CL, Cheng YY, Leu HB, et al. Increased risk of ischemic stroke in pa-
ment of these comorbidities may contribute to reducing the                tients with benign paroxysmal positional vertigo: a 9-year follow-up nation-
risk of BPPV recurrence, thereby improving prognosis. On the              wide population study in Taiwan. Front Aging Neurosci 2014;6:108. https://
other hand, identification of these risk factors provides some            doi.org/10.3389/fnagi.2014.00108
insight into risk evaluation for falls and contributes to help cli-
                                                                      5
                                                                          Liao WL, Chang TP, Chen HJ, et al. Benign paroxysmal positional vertigo is asso-
                                                                          ciated with an increased risk of fracture: a population-based cohort study. J Orthop
nicians counsel patients regarding the importance of follow-up            Sports Phys Ther 2015;45:406412. https://doi.org/10.2519/jospt.2015.5707
after diagnosis of BPPV. Furthermore, considering the fre-            6
                                                                          De Stefano A, Dispenza F, Suarez H, et al. A multicenter observational
quency of long-term recurrences, in most cases therapy with               study on the role of comorbidities in the recurrent episodes of benign par-
                                                                          oxysmal positional vertigo. Auris Nasus Larynx 2014;41:31-36. https://doi.
liberating manoeuvers seems sufficient, limiting preventive               org/10.1016/j.anl.2013.07.007
drug therapy to single selected cases. Our experience regarding       7
                                                                          Kim SY, Yoo DM, Min C, et al. Increased risk of neurodegenerative dementia
the recurrence of BPPV, despite the large number of patients,             after benign paroxysmal positional vertigo. Int J Environ Res Public Health
does not provide definitive results about the role of some de-            2021;18:10553 https://doi.org/10.3390/ijerph181910553
scribed risk factors. We evaluated only limited data (age, sex)       8
                                                                          Lopez-Escamez JA, Gamiz MJ, Fernandez-Perez A, et al. Long-term out-
                                                                          come and health-related quality of life in benign paroxysmal positional ver-
resulting from the clinical records, thus limiting the scientific         tigo. Eur Arch Otorhinolaryngol 2005;262:507-511. https://doi.org/10.1007/
significance of our paper, which was mainly designed as a mini            s00405-004-0841-x




                                                                                                                                                       S65
A.P. Casani, M. Gufoni




9
     Casani AP, Cerchiai N, Dallan I, et al. Anterior canal lithiasis: diagnosis           29
                                                                                                Tanimoto H, Doi K, Nishikawa T, et al. Risk factors for recurrence of be-
     and treatment. Otolaryngol Head Neck Surg 2011;144:412-418. https://doi.                   nign paroxysmal positional vertigo. J Otolaryngol Head Neck Surg
     org/10.1177/0194599810393879                                                               2008;37:832-835.
10
     Vannucchi P, Pecci R, Giannoni B. Posterior semicircular canal benign par-            30
                                                                                                Picciotti PM, Lucidi D, De Corso E, et al. Comorbidities and recurrence
     oxysmal positional vertigo presenting with torsional down-beating nystag-                  of benign paroxysmal positional vertigo: personal experience. Int J Audiol
     mus: a apogeotropic variant. Int J Otolaryngol 2012;2012:413603. https://doi.              2016;55:279-284. https://doi.org/10.3109/14992027.2016.1143981
     org/10.1155/2012/413603
                                                                                           31
                                                                                                Yeo SC, Ahn SK, Lee HJ, et al. Idiopathic benign paroxysmal positional
11
     Álvarez-Morujo de Sande MG, González-Aguado R, Guerra-Jiménez G, et
                                                                                                vertigo in the elderly: a long-term follow-up study. Aging Clin Exp Res
     al. Probable benign paroxysmal positional vertigo, spontaneously resolved:
     incidence in medical practice, patients’ characteristics and the natural course.           2018;30:153-159. https://doi.org/10.1007/s40520-017-0763-2
     J Otol 2019;14:111-116. https://doi.org/10.1016/j.joto.2019.04.002                    32
                                                                                                Chau AT, Menant JC, Hübner PP, et al. Prevalence of vestibular disorder in
12
     Zucca G, Valli S, Valli P, et al. Why do benign paroxysmal positional vertigo              older people who experience dizziness. Front Neurol 2015;6:268. https://doi.
     episodes recover spontaneously? J Vestib Res 1998;8:325-329.                               org/10.3389/fneur.2015.00268
13
     Andersson H, Jablonski GE, Nordahl SHG. The risk of benign paroxysmal                 33
                                                                                                Kong TH, Song MH, Shim DB. Recurrence rate and risk factors of recur-
     positional vertigo after head trauma. Laryngoscope 2022;132:443-448. htt-                  rence in benign paroxysmal positional vertigo: a single-center long-term
     ps://doi.org/10.1002/lary.29851                                                            prospective study with a large cohort. Ear Hear 2021;43:234-241. https://doi.
14
     Kutlubaev AM, Ying Xu, Hornibrook J. Benign paroxysmal positional ver-                     org/10.1097/AUD.0000000000001093
     tigo in Meniere’s disease: systematic review and meta‑analysis of frequen-            34
                                                                                                Li S, Wang Z, Liu Y, et al. Risk factors for the recurrence of benign parox-
     cy and clinical characteristics. J Neurol 2021;268:1608-1614. https://doi.                 ysmal positional vertigo: a systematic review and meta-analysis. Ear Nose
     org/10.1007/s00415-019-09502                                                               Throat J 2022;101:N112-N134. https://doi.org/10.1177/0145561320943362
15
     Balatsouras DG, Koukoutsis G, Ganelis P, et al. Benign paroxysmal posi-               35
                                                                                                D’Silva, LJ, Staecker H, Lin J, et al. Retrospective data suggests that the high-
     tional vertigo secondary to vestibular neuritis. Eur Arch Otorhinolaryngol
     2014;271:919-924. https://doi.org/10.1007/s00405-013-2484-2                                er prevalence of benign paroxysmal positional vertigo in individuals with type
                                                                                                2 diabetes is mediated by hypertension. J Vestib Res 2016;25:233-239. https://
16
     Bruss D, Abouzari M, Sarna B, et al. Migraine features in patients with recur-             doi.org/10.3233/VES-150563
     rent benign paroxysmal positional vertigo. Otol Neurotol 2021;42:461-465.
     https://doi.org/10.1097/MAO.0000000000002976
                                                                                           36
                                                                                                Cohen HS, Kimball KT, Stewart MG. Benign paroxysmal positional vertigo
17
     Fu CY, Zhang ZZ, Chen J, et al. Unhealthy lifestyle is an important risk fac-              and comorbid conditions. ORL J Otorhinolaryngol Relat Spec 2004;66:11-
     tor of idiopathic BPPV. Front Neurol 2020;11:950. https://doi.org/10.3389/                 15. https://doi.org/10.1159/000077227
     fneur.2020.00950                                                                      37
                                                                                                Luryi AL, Lawrence J, Bojrab DI, et al. Recurrence in benign paroxysmal po-
18
     Shih CP, Wang CH, Chung CH, et al. Increased risk of benign paroxysmal                     sitional vertigo: a large, single-institution study. Otol Neurotol 2018;39:622-
     positional vertigo in patients with non-apnea sleep disorders: a nationwide,               627. https://doi.org/10.1097/mao.0000000000001800
     population-based cohort study. J Clin Sleep Med 2018;14:20212029. https://            38
                                                                                                Yang X, Yang B, Wu M, et al. Association between serum uric acid levels and
     doi.org/10.5664/jcsm.7528                                                                  benign paroxysmal positional vertigo: a systematic review and meta-analysis
19
     Sreenivas V, Sima NH, Philip S. The role of comorbidities in benign parox-                 of observational studies. Front Neurol 2019;10:91. https://doi.org/10.3389/
     ysmal positional vertigo. Ear Nose Throat J 2021;100:NP225-NP230. https://                 fneur.2019.00091
     doi.org/10.1177/0145561319878546                                                      39
                                                                                                Minasyan A, Keisala T, Zou J, et al. Vestibular dysfunction in vitamin D re-
20
     Abdelmaksoud AA, Fahim DFM, Bazeed SES, et al. Relation between vi-                        ceptor mutant mice. J Steroid Biochem Mol Biol 2009;114:161-166. https://
     tamin D deficiency and benign paroxysmal positional vertigo. Sci Rep                       doi.org/10.1016/j.jsbmb.2009.01.020
     2021;11:16855. https://doi.org/10.1038/s41598-021-96445-x
                                                                                           40
                                                                                                Asprella Libonati GA, Leone A, Martellucci S, et al. Prevention of recurrent
21
     Neri G, Filograna Pignatelli GR, Pacella A, et al. Recurring paroxysmal po-
     sitional vertigo: evaluation of the vascular factor. Acta Otorhinolaryngol Ital            benign paroxysmal positional vertigo: the role of combined supplementation
     2021;41:77-83. https://doi.org/10.14639/0392-100x-n0502                                    with vitamin D and antioxidants. Audiol Res 2022;12:445-456. https://doi.
                                                                                                org/10.3390/audiolres12040045
22
     Nunez RA, Cass SP, Furman JM. Short- and long-term outcomes of canalith
     repositioning for benign paroxysmal positional vertigo. Otolaryngol Neck
                                                                                           41
                                                                                                Ishiyama A, Jacobson KM, Baloh RW. Migraine and benign position-
     Surg 2000;122:647-653. https://doi.org/10.1016/S0194-5998(00)70190-2                       al vertigo. Ann Otol Rhinol Laryngol 2000;109:377-380. https://doi.
23
     Brandt T, Huppert D, Hecht J, et al. Benign paroxysmal positioning ver-                    org/10.1177/000348940010900407
     tigo: a long-term follow-up (6-17 years) of 125 patients. Acta Otolaryngol            42
                                                                                                Hilton DB, Luryi AL, Bojrab DI, et al. Comparison of associated comorbid
     2006;126:160-163. https://doi.org/10.1080/00016480500280140                                conditions in patients with benign paroxysmal positional vertigo with or
24
     Sakaida M, Takeuchi K, Ishinaga H, et al. Long-term outcome of benign                      without migraine history: a large single institution study. Am J Otolaryngol
     paroxysmal positional vertigo. Neurology 2003;60:1532-1534. https://doi.                   2020;41:102650. https://doi.org/10.1016/j.amjoto.2020.102650
     org/10.1212/01.wnl.0000061477.03862.4d                                                43
                                                                                                Choi HG, Song YS, Wee JH, et al. Analyses of the relation between BPPV
25
     Chen J, Zhang S, Cui K, et al. Risk factors for benign paroxysmal posi-                    and thyroid diseases: a nested case-control study. Diagnostics 2021;11:329.
     tional vertigo recurrence: a systematic review and meta-analysis. J Neurol                 https://doi.org/10.3390/diagnostics11020329
     2020;268:4117-4127. https://doi.org/10.1007/s0041 5-020-10175-0                       44
                                                                                                Messina A, Casani AP, Manfrin M, et al. Italian survey on benign par-
26
     Choi SJ, Lee JB, Lim HJ, et al. Clinical features of recurrent or persistent benign        oxysmal positional vertigo. Survey italiana sulla vertigine parossistica
     paroxysmal positional vertigo. Otolaryngol Head Neck Surg 2012;147:919-
                                                                                                posizionale. Acta Otorhinolaryngol Ital 2017;37:328-335. https://doi.
     924. https://doi.org/10.1177/0194599812454642. Corrigendum. Otolaryngol
                                                                                                org/10.14639/0392-100X-1122
     Head Neck Surg 2013;149:798. https://doi.org/10.1177/0194599813505840
27
     Kim SY, Han SH, Kim YH, et al. Clinical features of recurrence and osteo-
                                                                                           45
                                                                                                Tricarico L, Di Cesare T, Galli J, et al. Benign paroxysmal positional vertigo:
     porotic changes in benign paroxysmal positional vertigo. Auris Nasus Larynx                is hypothyroidism a risk factor for recurrence? Acta Otorhinolaryngol Ital
     2017;44:156-161. https://doi.org/10.1016/j.anl.2016.06.006                                 2022;42:465-470. https://doi.org/10.14639/0392-100X-N1775
28
     Perez P, Franco V, Cuesta P, et al. Recurrence of benign paroxysmal posi-             46
                                                                                                Sfakianaki I, Binos P, Karkos P, et al. Risk factors for recurrence of benign
     tional vertigo. Otol Neurotol 2012;33:437-443. https://doi.org/10.1097/                    paroxysmal positional vertigo. a clinical review. J Clin Med 2021;10:4372.
     MAO.0b013e3182487f78                                                                       https://doi.org/10.3390/ jcm10194372




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