Analysis of influencing factors of residual dizziness after repositioning of horizontal semicircular canal benign paroxysmal positional vertigo.

BACKGROUND: Horizontal semicircular canal benign paroxysmal positional vertigo(HSC-BPPV) is the second most common type of BPPV. It is difficult to diagnose and treat, which has a serious impact on the prognosis of patients. OBJECTIVES: To study the clinical features of HSC-BPPV and the influencing factors of residual dizziness (RD). MATERIALS AND METHODS: The clinical data of 358 patients with BPPV were retrospectively collected. The differences between HSC-BPPV and posterior semicircular canal benign paroxysmal positional vertigo (PSC-BPPV) were compared, and the influencing factors of RD after HSC-BPPV repositioning were analyzed. RESULTS: ① Compared with PSC-BPPV, HSC-BPPV had a lower success rate of first repositioning (64.7 vs. 75.0%), a higher incidence of RD (57.3 vs. 43.8%), and a higher DHI score (40.0 vs. 34.0), and the differences were statistically significant (p < .05). ② Logistic regression analysis showed that age ≥60 years, secondary, DHI score, successful first repositioning were the influencing factors for the development of RD after HSC-BPPV repositioning (p < .05). CONCLUSIONS AND SIGNIFICANCE: The diagnosis and treatment of HSC-BPPV is difficult, and RD is prone to occur. Clinicians need to strengthen the training of HSC-BPPV diagnosis and treatment to reduce the occurrence and progression of RD.

Epley's Manoeuvre vs. Semont's Maneuver in Post-Canal Benign Paroxysmal Positional Vertigo: A Comparative Study in a Tertiary Centre.

Benign paroxysmal positional vertigo (BPPV) is a common vestibular disorder characterized by brief episodes of vertigo triggered by changes in head position. Epley's manoeuvre and Semont's manoeuvre are widely used canalith repositioning procedures for the treatment of BPPV. This study aimed to compare the effectiveness of these two manoeuvres in treating post-canal BPPV in a cohort of 100 patients. METHODS: This was a prospective, comparative study conducted at a tertiary care hospital. One hundred patients diagnosed with post-canal BPPV were randomized into two groups: Group A (n = 50) underwent the Epley's manoeuvre, and Group B (n = 50) underwent the Semont's manoeuvre. The patients were assessed for the resolution of vertigo and nystagmus immediately after the manoeuvre and at a follow-up visit one week later. The resolution of symptoms was confirmed through Dix-Hallpike test. RESULTS: In Group A, 46 patients (92%) reported complete resolution of vertigo immediately after Epley's manoeuvre, and 47 patients (94%) had no nystagmus on the Dix-Hallpike test at the one-week follow-up. In Group B, 42 patients (84%) reported complete resolution of vertigo immediately after Semont's manoeuvre, and 44 patients (88%) had no nystagmus on the DH test at the one-week follow-up. The difference in effectiveness between the two manoeuvres was not statistically significant (p > 0.05). CONCLUSION: Both Epley's manoeuvre and Semont's manoeuvre are effective in treating post-canal BPPV, with similar success rates. The choice of manoeuvre may depend on patient preference, clinician expertise, and other individual factors. Further studies with larger sample sizes are warranted to validate these findings and explore other potential factors influencing the outcomes of canalith repositioning manoeuvres in BPPV.

Serum Otoconin-90 and Otolin-1 Concentrations in Benign Paroxysmal Positional Vertigo.

OBJECTIVE: The aim was to evaluate the value of otolith-associated protein otoconin-90 (OC90) and otolin-1 in the pathogenesis research and clinical treatment of benign paroxysmal positional vertigo (BPPV). MATERIAL AND METHOD: The study included 50 patients with BPPV admitted to neurology and otorhinolaryngology departments and 30 healthy subjects with no history of dizziness as a control group. RESULTS: BPPV and controls were similar in terms of gender and age. Otolin-1 concentration was significantly greater in the BPPV group than in the controls (710.44 [584.35-837.39] vs 280.45 [212.7-419.61]; p < 0.001). No statistical significance was found, although OC90 was higher in the BPPV group than in the controls. There was a strong positive correlation between otolin-1 and OC90, a moderate negative correlation between otolin-1 and vitamin D, and a strong negative correlation between OC90 and vitamin D in the BPPV patient group. Otolin-1 had high specificity and AUC values for BPPV (AUC: 0.933; 95% CI: 0.881-0.986, 79.2% sensitivity, 100% specificity with a cutoff greater than 525). CONCLUSIONS: High serum concentrations of otolin-1 were associated with an increased risk of BPPV, but high concentrations of OC90 were not. Serum concentrations of otolin-1 can potentially be used as a biomarker for the acute onset of inner ear disorders due to the significant increase in patients with BPPV. Vitamin D has high specificity and sensitivity in patients with BPPV. It also provides evidence that BPPV patients with vitamin D deficiency may improve their symptoms with replacement therapy. More large-scale prospective studies are required to confirm these associations and clarify the exact mechanisms.

Brain Functional Alterations in Patients With Benign Paroxysmal Positional Vertigo Demonstrate the Visual-Vestibular Interaction and Integration.

OBJECTIVE: This study aimed to analyze the features of resting-state functional magnetic resonance imaging (rs-fMRI) and clinical relevance in patients with benign paroxysmal positional vertigo (BPPV) that have undergone repositioning maneuvers. METHODS: A total of 38 patients with BPPV who have received repositioning maneuvers and 38 matched healthy controls (HCs) were enrolled in the present study from March 2018 to August 2021. Imaging analysis software was employed for functional image preprocessing and indicator calculation, mainly including the amplitude of low-frequency fluctuation (ALFF), fractional ALFF (fALFF), percent amplitude of fluctuation (PerAF), and seed-based functional connectivity (FC). Statistical analysis of the various functional indicators in patients with BPPV and HCs was also conducted, and correlation analysis with clinical data was performed. RESULTS: Patients with BPPV displayed decrease in ALFF, fALFF, and PerAF values, mainly in the bilateral occipital lobes in comparison with HCs. Additionally, their ALFF and fALFF values in the proximal vermis region of the cerebellum increased relative to HCs. The PerAF values in the bilateral paracentral lobules, the right supplementary motor area (SMA), and the left precuneus decreased in patients with BPPV and were negatively correlated with dizziness visual analog scale (VAS) scores 1 week after repositioning (W1). In addition, in the left fusiform gyrus and lingual gyrus, the PerAF values show a negative correlation with dizziness handicap inventory (DHI) scores at initial visit (W0). Seed-based FC analysis using the seeds from differential clusters of fALFF, ALFF, and PerAF showed reductions between the left precuneus and bilateral occipital lobe, the left precuneus and left paracentral lobule, and within the occipital lobes among patients with BPPV. CONCLUSION: The spontaneous activity of certain brain regions in the bilateral occipital and frontoparietal lobes of patients with BPPV was reduced, whereas the activity in the cerebellar vermis was increased. Additionally, there were reductions in FC between the precuneus and occipital cortex or paracentral lobule, as well as within the occipital cortex. The functional alterations in these brain regions may be associated with the inhibitory interaction and functional integration of visual, vestibular, and sensorimotor systems. The functional alterations observed in the visual cortex and precuneus may represent adaptive responses associated with residual dizziness.

Addressing the Overlapping Challenges of Benign Paroxysmal Positional Vertigo (BPPV) and Persistent Postural-Perceptual Dizziness (PPPD): Impacts and Integrated Management.

Benign paroxysmal positional vertigo (BPPV) and persistent postural-perceptual dizziness (PPPD) are challenging vestibular disorders with overlapping symptoms that complicate diagnosis and treatment. BPPV causes transient vertigo with head movements, while PPPD involves persistent dizziness and unsteadiness. Both significantly impact the quality of life, including emotional well-being. This review examines the relationship between BPPV and PPPD, stressing the need for comprehensive, multidisciplinary management. Effective treatment must address both physical and psychological aspects, using personalized care, technological innovations, and patient education to improve outcomes and enhance the quality of life for those affected.

Acupuncture for Residual Dizziness After Successful Repositioning Maneuvers in Patients with Benign Paroxysmal Positional Vertigo: Study Protocol for a Randomized Noninferiority Trial.

Introduction: Benign paroxysmal positional vertigo (BPPV) is the most common cause of peripheral vertigo among adults. Successful treatment often requires an appropriate canalith repositioning procedure (CRP), which has proven effective in the treatment of BPPV. However, some patients experience residual dizziness (RD) after CRP, affecting their daily activities and quality of life. Although oral betahistine is a common clinical treatment for RD, some patients may discontinue this medication due to adverse effects. Conversely, acupuncture has demonstrated efficacy in treating dizziness with minimal adverse effects. However, to date, no trials have directly compared the efficacy of acupuncture and betahistine in treating RD. Our goal was to assess the noninferiority of acupuncture in treating RD compared with the commonly used oral betahistine treatment. Methods and Analysis: A randomized, controlled, non-inferiority trial was conducted to compare the effectiveness of acupuncture and betahistine in patients with BPPV who experience RD after a successful CRP. Eighty-four participants were randomly assigned to two treatment groups, each receiving either acupuncture or betahistine. The assessors and statisticians were blinded to treatment allocation. The primary outcomes were the response rate and change in vertigo level, and secondary outcomes included Visual Analog Scores and the presence and change in depressive symptoms among patients. Scale measures were recorded at baseline, 2, 4, and 12 weeks after randomization. This trial aims to provide causal evidence supporting the non-inferiority of acupuncture therapy relative to oral betahistine, offering an alternative treatment avenue for patients intolerant to betahistine. Ethics and Dissemination: Ethics approval was obtained from the Affiliated Hospital of Shandong University of Traditional Chinese Medicine, with permission number 2023-095-KY. Written informed consent was obtained from the enrolled patients.

Association between dizziness and future falls and fall-related injuries in older adults: a systematic review and meta-analysis.

BACKGROUND: Dizziness is common in older adults, especially in those attending falls services. Yet, the extent to which dizziness is associated with future falls has not been reviewed. This systematic review and meta-analysis assessed the association between dizziness and future falls and related injuries in older adults. METHODS: EMBASE, CINAHL Plus, SCOPUS and PsycINFO databases were searched from inception to 5 February 2024. The review was registered on PROSPERO (registration ID: CRD42022371839). Meta-analyses were conducted for the associations of dizziness with future falls (including recurrent and injurious falls). Three meta-analyses were performed on different outcomes: any-type falls (≥1 falls), recurrent falls (≥2 falls) and injurious falls. RESULTS: Twenty-nine articles were included in the systematic review (N = 103 306 participants). In a meta-analysis of 14 articles (N = 46 795 participants), dizziness was associated with significantly higher odds of any-type future falls (OR = 1.63, 95% CI = 1.44-1.84). In another meta-analysis involving seven articles (N = 5630 participants), individuals with dizziness also had significantly higher odds of future recurrent falls (OR = 1.98, 95% CI = 1.62-2.42). For both meta-analyses, significant overall associations were observed even when adjusted for important confounding variables. In contrast, a meta-analysis (three articles, N = 46 631 participants) revealed a lack of significant association between dizziness and future injurious falls (OR = 1.12, 95% CI = 0.87-1.45). CONCLUSIONS: Dizziness is an independent predictor of future falls in older adults. These findings emphasise the importance of recognising dizziness as a risk factor for falls and implementing appropriate interventions.

New- and early-onset benign paroxysmal positional vertigo after otologic surgery.

PURPOSE: To determine the frequency and clinical features of new- and early-onset benign paroxysmal positional vertigo (BPPV) after different otologic surgical operations with and without surgical drilling. METHODS: All unilateral otologic operations performed at the otolaryngology clinic of a tertiary university hospital between January 2021 and May 2023 were screened, and 437 adult cases were included in the study. Of these patients, those who were diagnosed with BPPV within the first month postoperatively were examined. RESULTS: The overall incidence of BPPV after otologic operations was 2.28% (10 out of 437 patients). This incidence was 3% (8/266 patients) in cases where a drill was used and 1.16% (2/171 patients) in those where a drill was not used. There was no significant difference between the two groups (p > 0.05). Clinical symptoms related to BPPV appeared on average in 13.3 ± 6.8 (range: 3-25) days following surgery and presented as canalolithiasis. All cases involved the posterior semicircular canal (SCC) on the operated side. In addition, one patient with a cochlear implant had involvement of both the posterior and lateral SCCs. All patients responded well to repositioning maneuvers during follow-up. CONCLUSION: Otologic surgery, especially operations involving drilling, is a potential risk factor for the development of BPPV. Postoperative BPPV, primarily presenting as canalolithiasis in the posterior SCC on the operated side, can be effectively managed with repositioning maneuvers. Clinicians should be vigilant for BPPV in patients experiencing vertigo/dizziness within four weeks following otologic surgery.

Partial Treatment During BPPV Diagnostic Maneuvers.

This study examines a case of lateral canal benign paroxysmal positional vertigo (BPPV) where the sequence of diagnostic positional maneuvers may have influenced the release of some canaliths into the utricle. Partial treatment during BPPV diagnostic maneuvers may complicate side identification during supine roll test, especially in canalolithiasis cases.

Impact of Epley's Manoeuvre on Quality of Life in Patients with Posterior Semicircular Canal Benign Paroxysmal Positional Vertigo: A Pre- and Post-Treatment Analysis.

Benign paroxysmal positional vertigo (BPPV) is a common vestibular disorder, predominantly affecting the posterior semicircular canal (PSC), and significantly impacts the quality of life (QoL) of patients. This study assesses the effectiveness of Epley's manoeuvre in improving QoL in patients with PSC-BPPV. This prospective analytical study, conducted at a tertiary care centre from January 2021 to December 2022, included 93 adult patients diagnosed with PSC-BPPV via the Dix-Hallpike test. Participants were evaluated using the dizziness handicap inventory (DHI) and visual vertigo analogue score (VAS) at baseline and on days 3, 10, and 30 post-treatments with Epley's manoeuvre. Data analysis focused on changes in DHI and VAS scores to assess the impact of treatment. The cohort comprised 58.1% males and 41.9% females, with a significant majority over 50 years of age. Notably, 90% of patients reported improvement by the first follow-up. Both DHI and VAS scores showed a statistically significant decrease over the follow-up period (p < 0.05), indicating a reduction in perceived dizziness and visual vertigo symptoms post-treatment. Epley's manoeuvre effectively improves the QoL in patients with PSC-BPPV, as evidenced by significant reductions in DHI and VAS scores. This study contributes to the evidence supporting Epley's manoeuvre as a key intervention in PSC-BPPV treatment, emphasizing its role in enhancing patient outcomes in clinical practice.

Diagnosis of Benign Paroxysmal Positional Vertigo Using a Questionnaire in a Hospital Based Rural Setting in India.

To develop and validate a simple questionnaire for the diagnosis of Benign Paroxysmal Positional Vertigo (BPPV) and also to accurately predict the involved side in BPPV. Patients (N = 148) who presented with dizziness to the ENT department were asked to fill out a questionnaire which was formulated to diagnose BPPV and the affected side. Five questions were part of the questionnaire. The fifth question was set to ascertain the affected side in BPPV. All the patients underwent a detailed neuro-otological examination and the findings were noted. The findings of the examination were correlated with the questionnaire findings. The mean age of the patient group was 54.72 years of age. The sensitivity of the questionnaire in detecting BPPV was 94.5%, though in 12.79% (n = 11) the side was not predicted correctly. The specificity of the questionnaire was 91.22%. The positive predictive value of the questionnaire in detecting BPPV was assessed at 94.5%.The questionnaire can be effectively used in predicting BPPV amongst patients presenting with dizziness and thus helps in avoiding unnecessary imaging and referrals to higher centres in view of suspicion of central causes of dizziness.

Enhancing BPPV Treatment Outcomes: A Comparative Study of the Epley Maneuver with and without the Dizzy-Fix Training Device.

INTRODUCTION: This study evaluates the effectiveness of combining the Epley Maneuver with the Dizzy-Fix Training Device in treating Benign Paroxysmal Positional Vertigo (BPPV), aiming to enhance treatment outcomes and patient satisfaction. METHODS: In this randomized controlled trial, 50 patients diagnosed with posterior canal BPPV were allocated into two groups: one receiving the traditional Epley Maneuver and the other undergoing the Epley Maneuver supplemented with the Dizzy-Fix Training Device. Key measures included the proportion of symptom-free patients at one month, changes in the Visual Analogue Scale (VAS) and Dizziness Handicap Inventory (DHI) scores, the recurrence rate within one month, and patient satisfaction. RESULTS: The Dizzy-Fix group achieved a significantly higher symptom resolution rate by day 7 (90% vs. 60%) and reported greater patient satisfaction (4.5/5 vs. 3.8/5) compared to the Epley Maneuver alone group. Additionally, this group exhibited a more substantial decrease in DHI scores (from an average of 30 to 5) and a lower recurrence rate (10% vs. 40%) within the first month post-treatment. CONCLUSION: Incorporating the Dizzy-Fix Training Device with the Epley Maneuver significantly improves the management of BPPV, evidenced by faster symptom resolution, enhanced patient satisfaction, and reduced symptom recurrence. These findings underscore the value of integrating real-time visual feedback technologies in vestibular rehabilitation, promising better patient outcomes, and advancing the quality of care in BPPV treatment.

A Study of Quality of Life Improvement in Videonystagmography Guided Epley's Manoeuvre in Posterior Canal Benign Paroxysmal Positional Vertigo.

To assess Quality of life improvement in Videonystagmography guided Epley's Manoeuvre in posterior canal benign paroxysmal positional vertigo. The design of present study is cross-sectional analytical study. The study is conducted in the Department of Otorhinolaryngology, Sri Aurobindo Medical College and Post Graduate Institute, Indore in association with Sri Aurobindo Institute of speech and hearing, Indore. Current study done to assess the effectiveness of canalolith repositioning procedures (Epley's maneuver) with and without drug therapy in posterior canal benign paroxsymal positional vertigo and to assess the patients based on Dizziness Handicap Inventory. All Patients who come to ENT OPD at Sri Aurobindo Medical College and Post Graduate Institute, Indore in the specified duration and according to the inclusion criteria were chosen in the study. Majority of the patients were in the age group of 18-58 years with the median age of 32 and subjective symptomatic relief on Epley's manoeuvre and DHI on day 15, 46 out of 60 subjects reported symptomatic relief with a percentage of 76.6%. This group of 46 subjects with symptomatic relief was labeled as resolved group. The age range in resolved group was between 18 and 58 years. Remaining 14 subjects, labelled as relapsed group were prescribed beta-histine and repeat Epley's maneuver was performed to assess the effectiveness of adjunct therapy. We conclude that a single Videonystagmography guided Epley's maneuver is an excellent tool for effective rehabilitation of majority of posterior canal BPPV alone and combined with adjunct betahistine therapy can even cure refractory cases providing them with better quality of life.

[Association between sleep disorders and vestibular vertigo].

Sleep disorders have a high comorbidity rate with vestibular diseases. The results of some small sample clinical studies have confirmed the effect of sleep deprivation on vestibular function. However, the mechanism of the effect of sleep disorder on vestibular system is still unclear. This article analyzes the possible mechanism of the effect of sleep disorders on vestibular function from the aspects of neuroanatomy and neurotransmitters, and summarizes the relationship between sleep disorder and benign paroxysmal positional vertigo, Meniere's disease, vestibular migraine and other diseases.

Incidence of Subsequent Injuries Associated with a New Diagnosis of Benign Paroxysmal Positional Vertigo and Effects of Treatment: A Nationwide Cohort Study.

Background/Objectives: Benign paroxysmal positional vertigo (BPPV) is the most common cause of recurrent vertigo and the most common peripheral vestibular disorder. It is characterized by intense vertigo triggered by head and position changes. This study investigates the risk of subsequent injury in BPPV patients and the effects of treatment. Methods: A population-based retrospective cohort study was conducted using data from the Longitudinal Health Insurance Database 2005 in Taiwan. Patients with and without BPPV were identified between 2000 and 2017. The study outcomes were diagnoses of all-cause injuries. The Kaplan-Meier method determined the cumulative incidence rates of injury in both cohorts, and a log-rank test analyzed the differences. Cox proportional hazard models calculated each cohort's 18-year hazard ratios (HRs). Results: We enrolled 50,675 patients with newly diagnosed BPPV and 202,700 matched individuals without BPPV. During follow-up, 47,636 patients were diagnosed with injuries (13,215 from the BPPV cohort and 34,421 from the non-BPPV cohort). The adjusted HR for injury in BPPV patients was 2.63 (95% CI, 2.49-2.88). Subgroup analysis showed an increased incidence of unintentional and intentional injuries in BPPV patients (aHR 2.86; 95% CI, 2.70-3.13 and 1.10; 95% CI, 1.04-1.21, respectively). A positive dose-response relationship was observed with increasing BPPV diagnoses. Treatment with canalith repositioning therapy (CRT) or medications reduced the risk of injury slightly but not significantly (aHR, 0.78; 95% CI, 0.37-1.29, 0.88; 95% CI, 0.40-1.40, respectively). Conclusions: BPPV is independently associated with an increased risk of injuries. CRT or medications have limited effects on mitigating this risk. Physicians should advise BPPV patients to take precautions to prevent injuries even after treatment.

Transcriptomic analysis reveals cross-talk genes between type 2 diabetes and recurrent benign paroxysmal positional vertigo.

Background: Benign paroxysmal positional vertigo (BPPV) is a common neurological disorder with a high recurrence rate. Type 2 diabetes mellitus (T2DM) is recognized as a risk factor for BPPV recurrence. However, the genomic association between T2DM and BPPV recurrence remains understudied. Methods: Differential gene expression analysis and weighted gene co-expression network analysis were used to identify shared genes between BPPV recurrence and T2DM. The MCC algorithm was employed to select hub genes from the protein-protein interaction network of the shared genes. The predictive efficacy of hub genes for BPPV recurrence and T2DM was assessed using ROC curve analysis. Genemania database was used to identify downstream targets of hub genes. The immune infiltration landscape of BPPV and T2DM was characterized using the CIBERSORT algorithm. Correlation analysis was performed to explore the relationship between hub genes and immune cells. The expression levels of hub genes in patient blood samples were validated using qPCR. Results: Thirteen shared genes were identified and a protein-protein interaction network was constructed for BPPV recurrence and T2DM. Subsequently, four hub genes were selected, and their expression levels effectively predicted the occurrence of BPPV recurrence and T2DM. These hub genes were highly correlated with immune cell infiltration, indicating a common mechanism underlying recurrent BPPV and T2DM. Finally, the upregulation of hub genes in patients with T2DM comorbid with BPPV recurrence was confirmed in blood samples. These hub genes may serve as predictive biomarkers for assessing the recurrence rate in BPPV patients with comorbid T2DM. Conclusion: We proposed shared gene characteristics between BPPV recurrence and T2DM, revealing an immune-mediated inflammatory regulation as a common pathway and identifying four immune-related biomarkers and potential therapeutic targets for T2DM comorbid with recurrent BPPV.

Corrigendum: Residual dizziness after BPPV management: exploring pathophysiology and treatment beyond canalith repositioning maneuvers.

[This corrects the article DOI: 10.3389/fneur.2024.1382196.].

Consensus paper on the management of acute isolated vertigo in the emergency department.

Acute vertigo is defined as the perception of movement of oneself or the surroundings in the absence of actual motion and it is a frequent cause for emergency department admissions. The utilization of medical resources and the duration of hospital stay for this kind of symptom is high. Furthermore, the efficiency of brain imaging in the acute phase is low, considering the limited sensitivity of both CT and MRI for diagnosing diseases that are the causes of central type of vertigo. Relying on imaging tests can provide false reassurance in the event of negative results or prolong the in-hospital work-up improperly. On the other hand, clinical examinations, notably the assessment of nystagmus' features, have proven to be highly accurate and efficient when performed by experts. Literature data point out that emergency physicians often do not employ these skills or use them incorrectly. Several clinical algorithms have been introduced in recent years with the aim of enhancing the diagnostic accuracy of emergency physicians when evaluating this specific pathology. Both the 'HINTS and 'STANDING' algorithms have undergone external validation in emergency physician hands, showing good diagnostic accuracy. The objective of this consensus document is to provide scientific evidence supporting the clinical decisions made by physicians assessing adult patients with acute vertigo in the emergency department, particularly in cases without clear associated neurological signs. The document aims to offer a straightforward and multidisciplinary approach. At the same time, it tries to delineate benchmarks for the formulation of local diagnostic and therapeutic pathways, as well as provide a base for the development of training and research initiatives.

Association between Benign Paroxysmal Positional Vertigo and Thyroid Diseases: Systematic Review and Meta-Analysis.

Introduction Benign paroxysmal positional vertigo (BPPV) is the peripheral vestibular dysfunction that most affects people worldwide, but its etiopathogenesis is still not fully understood. Considering the etiological diversity, some studies highlight the association between BPPV and thyroid diseases. Objective To investigate the association between thyroid diseases and BPPV. Data Synthesis Systematic review and meta-analysis of epidemiological studies searched in the PubMed, Web of Science, Embase, Cochrane Library, and Scopus databases. Studies that were fully available and investigated the association between BPPV and thyroid diseases were selected. The articles that composed the meta-analysis were analyzed using the dichotomous model, the Mantel-Haenszel statistical test, odds ratio (OR), and a 95% confidence interval (CI). Of the 67 articles retrieved from the databases, 7 met the eligibility criteria of the systematic review, and 4 had data necessary to perform the meta-analysis. Qualitative analysis revealed that the studies were conducted in the European and Asian continents. The predominant methodological design was the case-control type, and thyroid dysfunctions, hypothyroidism, and Hashimoto thyroiditis occurred more frequently. The meta-analysis showed no association between hypothyroidism and BPPV; however, there was a statistically significant relationship between Hashimoto thyroiditis and BPPV. Conclusion The meta-analysis results suggest a possible association between BPPV and Hashimoto thyroiditis. Nevertheless, we emphasize the need for further studies to elucidate the evidence obtained.

Retrospective analysis of nystagmus characteristics and clinical applications of positional testing in patients with cupulolithiasis of the posterior semicircular canal in benign paroxysmal positional vertigo.

Objective: This study aimed to investigate the characteristics of positional nystagmus in patients with cupulolithiasis of the posterior semicircular canal-benign paroxysmal positional vertigo (PC-BPPV-cu) to improve clinical diagnostic accuracy. Methods: This study retrospectively analyzed 128 cases of PC-BPPV-cu and 128 cases of canalolithiasis of BPPV (PC-BPPV-ca). General data, intensity, distribution, and the correlation of positional nystagmus were compared between the two groups. Results: Compared to the PC-BPPV-ca group, more cases from the PC-BPPV-cu group initially presented in the emergency department (P < 0.05). The most frequent positional nystagmus induced by PC-BPPV-cu was torsional-upbeat nystagmus, characterized by the upper pole of the affected eye beating toward the lower ear and vertically upward (387 cases, 59.7%). It was followed by torsional-downbeat nystagmus, characterized by the upper pole of the unaffected eye beating toward the lower ear and vertically downward (164 cases, 25.3%). The former represented posterior canal excitatory nystagmus (PC-EN), while the latter represented posterior canal inhibitory nystagmus (PC-IN). In the PC-BPPV-cu group, PC-EN was most easily caused by the Half Dix-Hallpike (HH) maneuver on the affected side, while PC-IN was most easily induced by a face-down position (FDP) on the unaffected side at approximately 45° angle (45° FDP). The vertical slow phase velocity (v-SPV) of positional nystagmus was more potent in the affected HH than in other positions with PC-EN (all P < 0.05); the v-SPV of positional nystagmus was greater in the 45° FDP than in different positions with PC-IN (all P < 0.05); the v-SPV of the affected Dix-Hallpike (DH) maneuver in the PC-BPPV-ca group was significantly greater than that of the affected HH maneuver in the PC-BPPV-cu group (P < 0.05). The a priori analysis showed that the strongest correlation with HH positional nystagmus was observed in the affected side roll test, followed by the DH maneuver. Conclusion: In the PC-BPPV-cu group, the HH maneuver most easily induced PC-EN on the affected side, and PC-IN was most easily induced by the 45° FDP. In some cases of PC-BPPV-cu, significant nystagmus was not observed to be induced in the DH position on the affected side; however, vertical rotation nystagmus was induced in the roll-test position on the affected side. In such cases, PC-BPPV-cu diagnosis should be considered, and HH and 45° FDP tests should be conducted to support the diagnosis.