Benign paroxysmal positional vertigo: a multi-center study

Benign paroxysmal positional vertigo (BPPV) is the most frequent vestibular disorder with significant morbidity, psychosocial impact, and medical costs. This multi-center study work aimed to review BPPV clinical features, treatment, and outcomes. After a detailed history, clinical examination, audiological assessment, and position provocation tests to diagnose BPPV type, the suitable repositioning maneuver was done. BPPV was diagnosed according to the criteria developed for this study through piloting and validation in a specialized dizziness clinic. The main outcome measures were patient demographics, comorbidities, canal involvement, response to treatment, and incidence of recurrence. Within included 114 patients, the affected canal was 93% posterior semicircular canal, 3.5% horizontal semicircular canal, and 3.5% anterior semicircular canal. The response after repositioning maneuver was (86%) after one session and 100% after the second session. Meticulous BBPV assessment with choosing appropriated provocation test help to diagnose and identify the type of BPPV and so applying appropriated suitable repositioning maneuver.


Background
Benign paroxysmal positional vertigo (BPPV) is a common vestibular disorder leads to significant morbidity, psycho-social impact, and medical costs. It is the most frequent cause of a vestibular disorder and represents about 20-30% of the vestibular vertigo with a lifetime prevalence reaches up to 2.4% in the general population [1].
It is believed to be attributed to dislodged otoliths from utricular macula into any of the semicircular canals, which results canalithiasis, or cupulolithiasis, if otoliths adhere to the cupula of the semicircular canal [2]. This results in bending and stimulation of the cupula and provoking vertigo and nystagmus in the plane of the affected canal [3].
The time course of BPPV is characterized by spontaneous remissions that occur typically after days to weeks and recurrences that occur in about 50% of patients [4,5]. Although BPPV is usually self-limiting, it inflicts a considerable personal and socioeconomic burden [1].
BPPV is categorized according to its cause into primary which is usually idiopathic and secondary. The primary type is the commonest type. The chief causes of secondary BPPV are after ear surgery, trauma to the head, vestibular neuronitis, insufficient blood supply of the vestibulobassilar system, and metabolic disorders [5,6].
There is a paucity of literature on the epidemiology of BPPV otorhinolaryngology practice in the Arab population. Thus, this study aimed to review the clinical features, treatment, and outcomes of BPPV in tertiary university hospitals in Arab population. Specifically, we

Open Access
The Egyptian Journal of Otolaryngology *Correspondence: mwenteg1973@gmail.com

Patients and methods
This study was conducted in the Otorhinolaryngology Department, Zagazig University, Egypt, and Alazhar University, Egypt, in collaboration with the Audiovestibular Department, Menoufia University, Egypt. This is a prospective study which involved 114 patients in the period from January 2019 to March 2021. The institutional review board (IRB) approved the study methods, and detailed consents were gained prior to inclusion in the research.
All the patients were subjected to a full and detailed history, general and clinical ENT examination, position provocation tests (Dix-Hallpike and supine roll test), and audiological assessment (tympanometry and pure tone audiometry). Patients with congenital ear anomalies or ear malignancies are excluded from the study.
The symptoms were clearly documented using the same criteria of Brevern et al. [1] to diagnose the vestibular vertigo and BPPV.
(3) Repeated dizziness with nausea and either imbalance or oscillopsia.
In Benign paroxysmal positional vertigo (A-D has to be fulfilled): BPPV in all patients was diagnosed by the above symptoms plus at least one positive test of Dix-Hallpike test, supine roll test, and deep midline head-hang test.
The test was considered positive when subjective vertigo was reported by the patient, and objective nystagmus was observed by the examiner. Nystagmus observed with the aid of videonystagmography (Visual Eyes by Micromedical Technologies, Chatham, IL) or Frenzel goggles (ICS-FL15, Otometrics, Denmark) in most of the cases.
Posterior semicircular canal BPPV (PSC-BPPV) was diagnosed by Dix-Hallpike test when a geotropic, torsional, upbeat nystagmus was observed associated with subjective vertigo while the affected ear down. Horizontal semicircular canal BPPV (HSC-0BPPV) was diagnosed by supine roll test when horizontal nystagmus was observed associated with subjective vertigo. It was considered geotropic if nystagmus beat toward the ground while the affected ear down and apogeotropic if nystagmus beat away from the ground while the affected ear up. Laterality was decided based on which side elicited more robust nystagmus and vertigo symptoms in cases where nystagmus and vertigo were present while either ear down. Anterior semicircular canal BPPV (ASC-BPPV) was diagnosed if apogeotropic, torsional, downbeat nystagmus was noticed while the affected ear up during the Dix-Hallpike test and/or downbeat nystagmus was noticed in the deep midline head-hang position.
Secondary BPPV was identified when a patient informs a history of acute unilateral vestibular loss or trauma to the head or surgery to the ear within 6 months of the onset of BPPV or intubation for general anesthesia within 3 days earlier.
All the patients are subjected to repositioning maneuver (Epley maneuver in cases of PSC-BPPV, barbeque maneuver in HSC-BPPV, and deep midline head-hang maneuver in ASC-BPPV) according to the affected canal.
After 2 weeks, if any of these patients is still complaining from vertigo, the patient subjected to the 2nd repositioning maneuver while using the oscillation on the mastoid. There are fixed instructions which are instructed to the patients to be followed in the first week after doing the repositioning maneuver either in the first or in the second attempt.
The patient has to avoid any trigger action which can allocate the otoconia again to any canal: The patient is considered not responding to the rehabilitation if after 6 weeks the patient is still having vertigo as well as a positive provocation test with the characteristic nystagmus (the same inclusion criteria).
All data were shown as means and standard deviation (SD). All statistical data were analyzed with the SPSS program version 25 (Chicago, Illinois, USA). When the P value < 0.05, it was reported as statistically significant.
Recurrent BPPV was reported in 22 patients (19.3%) and duration from previous attaches ranged from 1 month to 10 years. The duration of the symptoms ranged from 1 day to 6 months with a mean of 22.8 ± 26.8 days.
The canal affected was the posterior canal in 106 (93%) and the horizontal canal in 4 (3.5%) patients and the anterior canal in 4 (3.5%) patients (Table 3).  The side affected was the 56 canal in the right side (54 PSC and 2 ASC), and 58 canal was affected on the left side (52 PSC, 4 HSC, and 2 ASC). No bilateral canal affection was recorded ( Table 3). The side affected in the four horizontal canal patients was left side, where the side affected in four anterior canal patients were two left sides and two right sides.
Regarding the severity, vertigo was severe in 24 patients (21%), moderate in 50 patients (43.9%), and mild in 40 patients (35,1%). The four affected horizontal canals showed a severe form while in the affected 4 anterior canals, two were mild and the other two were moderate.

Discussion
Although the term "benign paroxysmal positional vertigo" (BPPV) was described for the first time in 1952 by Dix and Hallpike [7]; however, there is rarity in the literature on the epidemiology of BPPV.
The first study which estimate the prevalence and incidence of BPPV in the general adult population was performed by Brevern et al. in 2007 in Germany [1]. That study relied on telephone interview of the participants so it has many limitations as remote episodes can be easily forgotten, the diagnosis of BPPV depended on the analysis of the symptoms and not confirmed by positioning tests, and it could not differentiate between BPPV of the posterior canal and variants involving other canals.
In the current study, we tried to solve these limitations by doing a full study with full history-taking and positional provocation tests for BPPV not only to confirm the BPPV diagnosis but also to assess which canal is affected and hence apply the appropriate repositioning maneuver according to the affected canal and then assess the results. Complete physical and audiological examination has been done for all the patients to rule out any associated co-morbidity. To the best of our knowledge, this is the first such study in the Arab population.
This study involved 114 patients which is relatively larger than other similar studies; 60 patients in Panuganti et al. study [8], 75 patients in Babac and Arsović study [9], and 62 patients in Khatri et al. study [10].