Numerical Simulations of the Epley Maneuver With Clinical Implications.

OBJECTIVES: Canalith repositioning procedures to treat benign paroxysmal positional vertigo are often applied following standardized criteria, without considering the possible anatomical singularities of the membranous labyrinth for each individual. As a result, certain patients may become refractory to the treatment due to significant deviations from the ideal membranous labyrinth, that was considered when the maneuvers were designed. This study aims to understand the dynamics of the endolymphatic fluid and otoconia, within the membranous labyrinth geometry, which may contribute to the ineffectiveness of the Epley maneuver. Simultaneously, the study seeks to explore methods to avoid or reduce treatment failure. DESIGN: We conducted a study on the Epley maneuver using numerical simulations based on a three-dimensional medical image reconstruction of the human left membranous labyrinth. A high-quality micro-computed tomography of a human temporal bone specimen was utilized for the image reconstruction, and a mathematical model for the endolymphatic fluid was developed and coupled with a spherical particle model representing otoconia inside the fluid. This allowed us to measure the position and time of each particle throughout all the steps of the maneuver, using equations that describe the physics behind benign paroxysmal positional vertigo. RESULTS: Numerical simulations of the standard Epley maneuver applied to this membranous labyrinth model yielded unsatisfactory results, as otoconia do not reach the frontside of the utricle, which in this study is used as the measure of success. The resting times between subsequent steps indicated that longer intervals are required for smaller otoconia. Using different angles of rotation can prevent otoconia from entering the superior semicircular canal or the posterior ampulla. Steps 3, 4, and 5 exhibited a heightened susceptibility to failure, as otoconia could be accidentally displaced into these regions. CONCLUSIONS: We demonstrate that modifying the Epley maneuver based on the numerical results obtained in the membranous labyrinth of the human specimen under study can have a significant effect on the success or failure of the treatment. The use of numerical simulations appears to be a useful tool for future canalith repositioning procedures that aim to personalize the treatment by modifying the rotation planes currently defined as the standard criteria.

Altered parietal operculum cortex 2 functional connectivity in benign paroxysmal positional vertigo patients with residual dizziness: A resting-state fMRI study.

AIMS: To investigate changes in functional connectivity (FC) focusing on parietal operculum cortex 2 (OP2) in benign paroxysmal positional vertigo (BPPV) patients with residual dizziness (RD) after successful canalith repositioning procedure (CRP). METHODS: High-resolution three-dimensional T1 and resting-state functional magnetic resonance imaging (fMRI) were performed on 55 healthy controls (HCs), 55 BPPV patients with RD, and 55 patients without RD after successful CRP. Seed-based (bilateral OP2) FC was calculated to investigate the changes in FC among the three groups. Additionally, we further explored the associations between abnormal FC and clinical symptoms. RESULTS: One-way analysis of covariance showed significant FC differences among the three groups. Post-hoc analysis showed that patients with RD exhibited decreased FC between left OP2 and regions of left angular gyrus (AG), thalamus, precuneus, middle frontal gyrus (MFG), and right cerebellum posterior lobe (CPL) in comparison with HCs. In addition, compared with patients without RD, patients with RD showed decreased FC between left OP2 and regions of left MFG, AG, middle temporal gyrus, and right CPL. Moreover, in patients with RD, the FC between left thalamus and OP2 was negatively correlated with duration of RD, and the FC between left AG and OP2 was negatively correlated with duration of BPPV. CONCLUSION: BPPV patients with RD showed reduced FC between brain regions involved in vestibular processing and spatial cognition; These results suggested that BPPV patients with RD might have diminished central processing of vestibular information and impaired spatial cognition.

Semicircular canals are long in patients with benign paroxysmal positional vertigo.

OBJECTIVE: To search for any morphological variation contributing to aetiopathogenesis and the diagnosis of benign paroxysmal positional vertigo, we measured the sizes of the semicircular canals in patients with and without benign paroxysmal positional vertigo using multidetector computed tomography. METHODS: Cranial bone computed tomography images of 30 benign paroxysmal positional vertigo patients and 30 control patients were acquired with a 128-slice computed tomography scanner and a transverse plane with a thickness of 0.67 mm. The inner diameter, height and width of the canals were measured. RESULTS: The width of the anterior semicircular canals, and the width and height of the posterior semicircular canals of the affected ears in benign paroxysmal positional vertigo patients (n = 30) were significantly greater than in the control patients (n = 90; p = 0.001, p = 0.023, p = 0.003, respectively). CONCLUSION: In benign paroxysmal positional vertigo patients, the posterior and anterior semicircular canals are longer than those in people without benign paroxysmal positional vertigo. These morphological changes may contribute to elucidating the aetiopathogenesis and be used as a radiological sign for diagnosis of benign paroxysmal positional vertigo disease.

Magnetic resonance imaging of the endolymphatic space in patients with benign paroxysmal positional vertigo: volume ratio and distribution rate of the endolymphatic space.

BACKGROUND: Benign paroxysmal positional vertigo (BPPV) is the most common peripheral vestibular disease. It is characterised by sudden onset short lived vertigo triggered by sudden changes in head position relative to gravity. AIMS/OBJECTIVES: We aimed to perform a quantitative volumetric analysis of the inner ear endolymphatic space in patients with BPPV. MATERIAL AND METHODS: This study included 67 patients with BPPV and 50 control subjects (CS). The endolymphatic space/total fluid space volume ratio (%) and the distribution rate of the inner ear components in the endolymphatic space (%) were measured using three-dimensional magnetic resonance imaging. RESULTS: Differences in the endolymphatic space/total fluid space volume ratio of the inner ear, cochlea, vestibule, and semi-circular canals (SCCs) between the CS and BPPV groups were not significant. The endolymphatic space distribution rate of the vestibule in the BPPV group was significantly lower than that in the CS group, and the endolymphatic space distribution rate of SCCs in the BPPV group was significantly higher than that in the CS group. CONCLUSIONS AND SIGNIFICANCE: Extended endolymphatic space in patients with BPPV did not exist. The otoconia released from the damaged utricles were considered to move with the endolymphatic flow toward SCCs.

Visualization of horizontal canal benign paroxysmal positional vertigo using 3DCT imaging and its assessment.

BACKGROUND: There have been no useful imaging methods to diagnose benign paroxysmal positional vertigo (BPPV), a common cause of vertigo, depending on the characteristic symptom. OBJECTIVE: To visualize horizontal canal (HC) BPPV using 3DCT and assess its clinical usefulness. SUBJECTS AND METHODS: Ten BPPV patients were diagnosed with distinct BPPV, canalolithiasis, and cupulolithiasis of the HC (hc-BPPV, hc-BPPV-cu), which were definitely diagnosed on the basis of criteria of BPPV by the Barany Society and 10 healthy subjects without a history of dizziness were investigated using 3DCT with several different CT window values (CTWVs). RESULTS: The HCs of BPPV patients were clearly visualized and the luminal aspects showed differences among ears with cupulolithiasis, canalolithiasis and no symptoms healthy subjects. CONCLUSIONS AND SIGNIFICANCE: 3DCT images visualized the characteristic changes of the HC of patients with BPPV compared to healthy subjects. The HC images were coincident with the clinical condition of cupulolithiasis and canalolithiasis. This imaging technique is clinically useful for diagnosing, treating and assessing the prognosis of HC BPPV.

Structural and Functional Changes in the Cerebellum and Brainstem in Patients with Benign Paroxysmal Positional Vertigo.

Benign paroxysmal positional vertigo (BPPV) is one of the most common peripheral vestibular diseases. Since the peripheral vestibular system connects with the cerebellum via the brainstem, repeated episodic vertigo may result in progressive structural and functional changes in the cerebellum and brainstem. In the present work, voxel-based morphometry (VBM) of T1-weighted images and resting-state functional magnetic resonance imaging (fMRI) in 32 patients with BPPV and 32 matched healthy controls were used to assess cerebellar and brainstem anatomical and spontaneous resting-state brain activity alterations associated with BPPV. We used a spatially unbiased infratentorial template toolbox in combination with VBM to analyze cerebellar and brainstem gray matter volume (GMV), fractional amplitude of low-frequency fluctuations (fALFF), and regional homogeneity (ReHo). Patients with BPPV showed decreased GMV in the right cerebellum posterior lobe/cerebellar tonsil extending to the cerebellum anterior lobe and pons relative to healthy controls. BPPV patients also exhibited significantly higher fALFF values in the right pons and left pons and higher ReHo values in the left cerebellum posterior lobe/Crus2 than the controls. Furthermore, the fALFF z-scores in the pons were positively correlated with the duration of vertigo at baseline and dizziness visual analog scale scores 1 week after canalith repositioning procedures (CRPs). BPPV patients exhibited structural and functional changes in the cerebellum and pons, which may reflect the adaptation and plasticity of these anatomical structures after repeated attacks of episodic vertigo. These results indicate that the changes in pons function may be closely related to residual dizziness after CRPs.

Carotid imaging changes and serum IL-1ß, sICAM-1, and sVAP-1 levels in benign paroxysmal positional vertigo.

Benign paroxysmal positional vertigo (BPPV) is the most common cause of vertigo. This study was performed to evaluate serum levels of inflammatory factors and changes in B-mode carotid ultrasound findings in patients with BPPV. The study population consisted of 90 BPPV patients and 90 age- and sex-matched controls. ELISA was used to compare the levels of inflammatory factors, such as interleukin-1ß (IL-1ß), tumor necrosis factor-alpha (TNF-α), soluble intercellular adhesion molecule-1 (sICAM-1), prostaglandin-E2 (PG-E2), and soluble vascular adhesion protein-1 (sVAP-1), between BPPV patients and controls. In addition, the results of ultrasonographic imaging to determine carotid intima-media thickness (C-IMT), carotid atheromatous plaque, and vertebral artery stenosis were also compared between the BPPV and control groups. Serum levels of IL-1ß, sICAM-1, and sVAP-1 were significantly higher in BPPV patients than controls (P < 0.001, P < 0.05, and P < 0.001, respectively). C-IMT and vertebral artery stenosis were significantly different in BPPV patients compared to controls (both P < 0.05). There were no significant relations between other parameters and BPPV. IL-1ß, sICAM-1, and sVAP-1 are potentially associated with the pathogenesis of BPPV, and C-ITM and carotid vertebral stenosis may be useful reference imaging findings for the diagnosis of BPPV.

Results in caloric test, video head impulse test and inner ear MRI in patients with Ménière's disease.

OBJECTIVE: Our aim was to elucidate relationships between results from the caloric test (c-test), video Head Impulse Test (vHIT) and inner ear gadolinium-enhanced MRI (ieMRI) in patients with endolymphatic hydrops (EH), especially patients with Ménière's disease (MD). METHODS: We managed 1789 successive patients at the Vertigo/Dizziness Center in Nara Medical University from May 2014 to December 2018. After providing informed consent for vertigo/dizziness examinations, 281 patients were hospitalized to check their inner ear function for proper diagnosis and treatment. Then 76 participants underwent the c-test, vHIT and ieMRI. Among these 76 cases, 20 were diagnosed with MD (20/76; 26.3%) and 56 were non-MD (56/76; 73.7%) according to the 2015 diagnostic guideline of the International Classification of Vestibular Disorders. The MD group included 15 unilateral and 5 bilateral cases. The non-MD group included 22 benign paroxysmal positional vertigo, 10 vestibular neuritis, 8 sudden deafness with vertigo, 6 orthostatic dysregulation, 4 vestibular neuropathy and 6 others. Results in these examinations in the side of an active lesioned inner ear were representative in each peripheral case. RESULTS: Twenty-nine of the 76 patients (38.1%) showed discrepant results between the c-test (outside of normal range) and vHIT (within normal range). Twenty-two of 76 patients (28.9%) had a positive EH sign on ieMRI. The c-test/vHIT discrepancy percentage in MD (14/20; 70.0%) was significantly higher than that in non-MD (15/56; 26.8%) (p=0.00179). The positive EH sign in ieMRI percentage in MD (15/20; 75.0%) was significantly higher than that in non-MD (7/56; 12.5%) (p=0.0015). There was a significant positive relationship between the c-test/vHIT discrepancy and the positive EH sign (p=0.00058) in all 76 cases combined. However, there was no significant relationship between c-test/vHIT discrepancy and positive EH sign (p=0.13) in the 20 MD cases. Considering the 15 unilateral and 5 bilateral MD cases, the c-test/vHIT discrepancy was observed in 14 of the 25 affected ears. Positive signs of vestibular EH herniation into the cupula in the lateral semicircular canal was seen in 14 of the 25 MD ears. There was significant relationship between the c-test/vHIT discrepancy and EH herniation (p=0.0012) in MD ears. CONCLUSION: The present results suggest that patients with MD could have inner ear EH significantly more often than those with non-MD. In cases with MD, a positive EH sign on ieMRI did not always indicate a c-test/vHIT discrepancy; both findings may occur due to herniation of vestibular EH adjacent to the lateral semicircular canal.

Implementation of Evidence-Based Practice for Benign Paroxysmal Positional Vertigo in the Emergency Department: A Stepped-Wedge Randomized Trial.

STUDY OBJECTIVE: We evaluated a strategy to increase use of the test (Dix-Hallpike's test [DHT]) and treatment (canalith repositioning maneuver [CRM]) for benign paroxysmal positional vertigo in emergency department (ED) dizziness visits. METHODS: We conducted a stepped-wedge randomized trial in 6 EDs. The population was visits with dizziness as a principal reason for the visit. The intervention included educational sessions and decision aid materials. Outcomes were DHT or CRM documentation (primary), head computed tomography (CT) use, length of stay, admission, and 90-day stroke events. The analysis was multilevel logistic regression with intervention, month, and hospital as fixed effects and provider as a random effect. We assessed fidelity with monitoring intervention use and semistructured interviews. RESULTS: We identified 7,635 dizziness visits during 18 months. The DHT or CRM was documented in 1.5% of control visits (45/3,077; 95% confidence interval 1% to 1.9%) and 3.5% of intervention visits (159/4,558; 95% confidence interval 3% to 4%; difference 2%, 95% confidence interval 1.3% to 2.7%). Head CT use was lower in intervention visits compared with control visits (44.0% [1,352/3,077] versus 36.9% [1,682/4,558]). No differences were observed in admission or 90-day subsequent stroke risk. In fidelity evaluations, providers who used the materials typically reported positive clinical experiences but provider engagement was low at facilities without an emergency medicine residency program. CONCLUSION: These findings provide evidence that an implementation strategy of a benign paroxysmal positional vertigo-focused approach to ED dizziness visits can be successful and safe in promoting evidence-based care. Absolute rates of DHT and CRM use, however, were still low, which relates in part to our broad inclusion criteria for dizziness visits.

Measurement of horizontal ocular deviation on magnetic resonance imaging in various disease with acute vertigo.

In our previous study, we found that horizontal ocular deviation (OD) was significantly increased in patients with unilateral vestibular neuritis (VN). This study is aimed to compare the measurements of horizontal OD in various diseases which can present as acute vertigo in the emergency department. We retrospectively reviewed patients who visited the emergency department and underwent brain MRI due to acute vertigo. We compared them to healthy controls who underwent brain MRI for a regular health examination. Among the study participants, 149 patients who were diagnosed with benign paroxysmal positional vertigo (BPPV), unilateral Ménière's disease (MD), vestibular migraine (VM), unilateral vestibular neuritis (VN), or posterior inferior cerebellar artery (PICA) infarction were enrolled. Absolute angles of horizontal OD were larger in the definite MD (19.1 ± 12.7°), possible and probable MD (15.5 ± 11.7°), and VN (22.2 ± 11.7°) groups compared to the control group (4.3 ± 3.7°). Most VN patients (83.3%) had horizontal OD toward the direction of the lesion. About half of the MD patients (46.2%) and half of the patients with PICA infarction (50.0%) had horizontal OD toward the opposite direction of the lesion. Regarding PICA infarction, horizontal OD was observed only in patients who immediately underwent an MRI after developing the PICA territory vestibulocerebellar infarction. Although the exact mechanism of horizontal OD is unclear, this study suggests that horizontal OD reflects a static vestibular imbalance, and that the eyeball is deviated to the weaker of the two vestibular nuclei during neural resting activity. Therefore, horizontal OD could be helpful in assessing for a prior vestibular imbalance.

A comparison of benign positional vertigo and stroke patients presenting to the emergency department with vertigo or dizziness.

PURPOSE: To compare imaging utilization between patients presenting to the emergency department (ED) with vertigo and dizziness (VDS) who are diagnosed with stroke and benign paroxysmal positional vertigo (BPPV). METHODS: All patients presenting to the ED with VDS (January 2014-June 2018) were identified. Those with a discharge diagnosis of stroke and BPPV were analyzed. RESULTS: 17,884 patients presented to with VDS. 452 were diagnosed with BPPV and 174 with acute stroke. 55.7% of stroke patients had at least one neurologic symptom beyond VDS, 63.8% had a positive neurologic exam, and 80.5% had either; 90.2% had at least one stroke risk factor (RF). 42.0% of BPPV patients received imaging, of which 24.7% had neurologic symptoms beyond VDS, 16.3% had neurologic exam findings, and 34.2% had either (P < 0.001, as compared to stroke). 43 patients (22.6%) lacked neurologic symptoms, exam findings, and stroke RFs; 40 had an adequate HINTS (head impulse, nystagmus, skew) exam. The most common imaging modality received by BPPV patients was plain CT Head (54.2%), followed by CT/CTA (43.7%), and MRI brain (26.3%). CT head was the initial imaging of choice in 44.7% and CT/CTA in 42.6%. CONCLUSIONS: Imaging utilization in BPPV patients presenting with VDS is high. The profile of patients with BPPV that received imaging was substantially more benign than that of stroke patients (a quarter had no neurologic symptoms, exam findings, or stroke RFs). The HINTS exam was underutilized, and computed tomography was heavily utilized despite well-established limitations in diagnosing posterior circulation strokes. This study highlights the need for increased training in the HINTS exam, narrowing of the scope for computed tomography, and a higher threshold for imaging patients with isolated VDS.

Idiopathic benign paroxysmal positional vertigo with persistent vertigo/dizziness sensation is associated with latent canal paresis, endolymphatic hydrops, and osteoporosis.

OBJECTIVE: The aim of the present study was to examine the association of neuro-otological examination, blood test, and scoring questionnaire data with treatment-resistant intractability in idiopathic benign paroxysmal positional vertigo (BPPV) patients. METHODS: We experienced 1520 successive vertigo/dizziness patients at the Vertigo/Dizziness Center in Nara Medical University during May 2014 to April 2018. Six hundred and eleven patients were diagnosed as BPPV (611/1520; 40.2%) according to the diagnostic guideline of the International Classification of Vestibular Disorder in 2015. Among BPPV patients, there were 201 intractable patients (201/611; 32.9%), 66 of whom were idiopathic and enrolled to be hospitalized and receive neuro-otological examinations, including the caloric test (C-test), vestibular evoked cervical myogenic potentials (cVEMP), subjective visual vertical (SVV), glycerol test (G-test), electrocochleogram (ECoG), inner ear magnetic resonance imaging (ieMRI), blood tests including anti-diuretic hormone (ADH) and bone alkaline phosphatase (BAP), and self-rating questionnaires of depression score (SDS). Sixty-six patients were diagnosed as horizontal type cupula (hBPPVcu; n=30), horizontal type canal (hBPPVca; n=10), posterior type (n=20), and probable and/or atypical BPPV (n=6). Data are presented as ratios (+) of the number of idiopathic BPPV patients with examination and questionnaire data outside of the normal range. RESULTS: The ratio (+) data were as follows: C-test=21.2% (14/66), cVEMP=24.2% (16/66), SVV=48.5% (32/66), G-test=18.2% (12/66), ECoG=18.2% (12/66), ieMRI=12.1% (8/66), ADH=9.1% (6/66), BAP=13.6% (9/66), and SDS=37.9% (25/66). Multivariate regression analysis revealed that the periods of persistent vertigo/dizziness were significantly longer in BPPV patients with hBPPVcu, C-test (+), endolymphatic hydrops (+), and BAP (+) compared with those with negative findings. CONCLUSION: Although patients with idiopathic BPPV are usually treatable and curable within 1 month, the presence of hBPPVcu, canal paresis, endolymphatic hydrops, and elevated BAP may make the disease intractable, and thus require additional treatments.

Identification of factors related to cases of benign paroxysmal positional vertigo refractory to canalicular repositioning maneuvers and evaluation of the need for magnetic resonance imaging in their management: retrospective analysis of a series of 176 cases

Introduction: Benign paroxysmal positional vertigo (BPPV) is the most common form of peripheral vertigo, and, in most cases, it presents a favorable prognosis. The treatment is based on a series of specific canalicular repositioningmaneuvers that offer an efficacy close to 100%. Despite this, there are cases that are refractory to treatment, with the persistence of the vertigo symptoms. Objectives: The objective of the present paper is to analyze the factors associated with an increased risk of refractory BPPV and the importance of nuclear magnetic resonance in the study of these patients. Methods: We retrospectively reviewed the cases of 176 patients diagnosed with BPPV in our center.We divided them into two groups: responders and non-responders to the treatment, and analyzed the possible risk factors associated with a higher risk of refractory vertigo. Fischer exact test was used. Results: We found 11 cases refractory to treatment; all of them underwent magnetic resonance imaging (MRI) with gadoliniumaccording to our protocol. Of these, four had an otoneurologic background or pathology, and two other patients presented a multicanal involvement. The difference between the two groups was statistically significant (p < 0.05). Conclusion: Otoneurologic background and multicanal involvement were associated with a higher risk of refractory BPPV. When dealing with a BPPV with persistent symptomatology/nystagmus or with early relapse after an initial improvement, other entities that enter into the differential diagnosis must always be considered. We consider it essential to perform an MRI with gadolinium to rule out cases of BPPV that have a central cause (AU)

White matter lesions in magnetic resonance imaging of the brain in 56 patients with visual vertigo.

BACKGROUND: Visual vertigo is defined as a condition in which there is worsening or triggering of vestibular symptoms in certain visual environments. Previous studies have associated visual vertigo with an increased prevalence of underlying white matter lesions on brain imaging. METHOD: This study evaluated the magnetic resonance imaging scans of the brain from a cohort of patients with visual vertigo, and compared the outcomes to an age- and gender-matched group of healthy volunteers.Results and conclusionWhite matter lesions were observed in 17.9 per cent of the patient group and in 16.3 per cent of the control group. The prevalence of white matter lesions in the patient group was not too different to that expected based on age.

Benign paroxysmal positional vertigo in spontaneous intracranial hypotension.

OBJECTIVES: To assess the prevalence and related factors of benign paroxysmal positional vertigo (BPPV) in patients with spontaneous intracranial hypotension (SIH). METHODS: We retrospectively reviewed 156 consecutive inpatients with SIH, and collected the clinical and radiological data. These patients were divided into BPPV group and non-BPPV group according to the clinical manifestation and the results of Dix-Hallpike or supine roll tests during hospitalization period. We performed a univariate analysis and a further multiple logistic regression analysis to identify the related factors of the development of BPPV in SIH patients. RESULTS: BPPV was detected in 18 patients among the total 156 SIH patients (11.54%). The univariate analysis showed a low cerebrospinal fluid (CSF) pressure (P = 0.018), a small pontomesencephalic angle (P = 0.012) and a positive venous distension sign (VDS) (P = 0.045) were associated with the presence of BPPV. But the multivariate analysis only demonstrated a low CSF pressure was related to the presence of BPPV (OR = 1.022, 95% CI: 1.001-1.043, P = 0.044). CONCLUSION: BPPV is common in SIH patients. SIH patients with low CSF pressure may be prone to develop BPPV.

Our experience with 500 patients with benign paroxysmal positional vertigo: Reexploring aetiology and reevaluating MRI investigation.

OBJECTIVE: To explore the aetiology of and to evaluate the importance of MRI investigation on the posterior semicircular canal benign paroxysmal positional vertigo in an Irish population. METHODS: A retrospective observational study of 500 patients with posterior semicircular canal benign paroxysmal positional vertigo, diagnosed and treated by the senior author over a 10-year period. Most patients underwent an MRI brain and inner ear, following the same scan protocol. This included T1 weighted sagittal IR-FSPGR volume, axial T2 weighted, gradient echo T2 weighted and FLAIR sequences plus time of flight cerebral angiography. RESULTS: The average age of presentation was 56 years; with the overall female to male ratio was 1.6:1, which was largely the net results of 2 age groups. Over 30% of our patients recalled distinct aetiological triggers, of which the top 3 were trauma, infection, and surgery. These accounted for 16%, 6%, and 5%, respectively. More than 25% of the patients were discovered to have abnormal intracranial findings on MRI. The 2 most common non-infarct incidental findings were neoplasia and vascular abnormalities. Although fewer than 20 patients had acute intracranial haemorrhage or malignant tumours, most of them were urgently referred to neurosurgeon due to the life-threatening nature of the condition. One round of particle repositioning manoeuver was successful in treating 84% of the patients, and the 2-year recurrence rate was only 2.2%. CONCLUSION: The diagnosis of posterior semicircular canal benign paroxysmal positional vertigo is thought to be relatively easy to make, and the treatment is highly effective. Clinicians should be fully aware of and prepared for the diverse aetiology, and thus have no hesitation in requesting MRI scan as an important investigation.

Magnetic resonance imaging predicts chronic dizziness after benign paroxysmal positional vertigo.

OBJECTIVES: We aimed to evaluate the clinical implications of magnetic resonance imaging (MRI) findings in patients with benign paroxysmal positional vertigo (BPPV). METHODS: A total of 120 patients diagnosed with BPPV completed MRI at the emergency room between December 2012 and June 2015 and met our criteria for inclusion in this study. Epidemiologic characteristics, the results of audio-vestibular testing, and MRI findings were retrospectively analyzed. RESULTS: The most common findings were white matter hyperintensities (70.0%), sinusitis (34.2%), and brain atrophy (25.0%). There were no significant differences in MRI findings or epidemiologic characteristics according to BPPV subtype (p>0.05). A multiple regression analysis revealed that BPPV recurrence (odds ratio, 6.88; 95% confidence interval, 1.67-34.48; p=0.009) and brain atrophy (odds ratio, 4.39; 95% confidence interval, 1.11-21.28; p=0.036) were positively associated with dizziness lasting longer than 3months. CONCLUSION: Brain atrophy was independently associated with long-lasting dizziness after BPPV. Although the mechanism is unclear, brain atrophy may have relevance to otoneurotologic disease-related changes in brain structure.

[Otoconia : Current aspects of research]. / Otokonien : Aktuelle Aspekte aus der Forschung.

Otoconia are calcite-based nanocomposites containing >90 % calcite and <10 % organic material. The mean size is approximately 10 µm. The external structure of all otoconia in the utricle and saccule is similar, with a cylindrical bulbous body with a slightly hexagonal contour. The internal structure consists of a composite with varying volume thickness, dense branching structures (branches) and less dense surrounding areas (bellies). Intact otoconia can be clearly identified only by scanning electron microscopy. In the case of morphological changes (e.g. due to "degeneration") the origin of even very small particles of otoconia can be assigned using physical and chemical analytical methods. The inorganic component of otoconia (calcite) is extremely sensitive to chemical influences, which leads to morphological alterations. A "degeneration" of otoconia can be objectively accomplished in vitro by alterations in pH, electrolyte imbalance and by the influence of complex formation. These three main processes then lead to irreversible morphological alterations. Artificial (biomimetic) otoconia serve as a suitable model system for detailed investigation of growth and degenerative processes.