ABSTRACT
OBJECTIVE: To evaluate otolithic functions in patients with residual dizziness after successful canalith repositioning procedures (CRPs) for unilateral posterior canal benign paroxysmal positional vertigo (BPPV), and to investigate possible risk factors. METHODS: This case-control observational study included healthy controls and patients with residual dizziness after improvement following CRP for BPPV. All participants were subjected to full history taking, otoscopy, audiological basic evaluation, Dix-Hallpike test to search for posterior canal BPPV, residual dizziness screening, and vestibular evoked myogenic potential (VEMP) testing. Between-group differences were assessed and possible factors associated with residual dizziness were identified by univariate analysis. RESULTS: A total of 50 patients with residual dizziness (mean age, 56.53 ± 7.46 years [29 female: 21 male]) and 50 healthy controls (mean age, 58.13 ± 7.57 years [20 female: 30 male]) were included. A significant difference in VEMP latencies was found between the patient and control group (delayed in the patient group), with no significant between-group difference in amplitude in both ears. Aging, female sex, long duration of BPPV, number of CRPs, cervical VEMP and ocular VEMP abnormalities, and winter onset, were significantly associated with the risk of residual dizziness. CONCLUSIONS: Residual dizziness is a frequent sequel of BPPV that may relate to otolithic dysfunction. VEMP changes were revealed in the form of delayed latencies.
Subject(s)
Benign Paroxysmal Positional Vertigo , Dizziness , Otolithic Membrane , Vestibular Evoked Myogenic Potentials , Humans , Female , Male , Middle Aged , Benign Paroxysmal Positional Vertigo/physiopathology , Benign Paroxysmal Positional Vertigo/diagnosis , Benign Paroxysmal Positional Vertigo/therapy , Otolithic Membrane/physiopathology , Case-Control Studies , Dizziness/physiopathology , Dizziness/etiology , Vestibular Evoked Myogenic Potentials/physiology , Aged , Patient Positioning/methodsABSTRACT
OBJECTIVES: Vestibular evoked myogenic potentials (VEMPs) are useful for studying the disturbances along nerve pathways implicated in the transmission of neurological information from otolithic organs related to vestibular function. This study aims to determine the differences in VEMPs in patients affected with benign paroxysmal positional vertigo (BPPV). METHODS: We recruited 36 patients, 9 diagnosed with recurrent BPPV (rBPPV), 9 with only one episode of vertigo (iBPPV), and 18 as a control group. We performed cervical and ocular VEMPs (cVEMPs and oVEMPs). RESULTS: We observed differences in asymmetry ratio, which was 41.82% in cVEMPs in iBPPV and 68.27% in oVEMPs in rBPPV, while no asymmetry was found in control cases. Also, there was a lack of both VEMP responses in 22.2% of cases and an absence of cVEMP in 11.1% in iBPPV; in rBPPV, 11.1 % presented no responses in cVEMPs or oVEMPs, 22.2% showed no oVEMP, and 11.1% showed no cVEMP. These values were normal in the control group. CONCLUSION: The value of VEMPs in BPPV demonstrates the implication of vestibular damage, mainly utricle damage. For better sensitivity in detecting otolith abnormalities, we should perform oVEMPs and cVEMPs in recurrent BPPV and early stages of BPPV.
Subject(s)
Benign Paroxysmal Positional Vertigo , Vestibular Evoked Myogenic Potentials , Humans , Vestibular Evoked Myogenic Potentials/physiology , Benign Paroxysmal Positional Vertigo/diagnosis , Benign Paroxysmal Positional Vertigo/physiopathology , Female , Male , Middle Aged , Adult , Aged , Recurrence , Case-Control Studies , Otolithic Membrane/physiopathologyABSTRACT
BACKGROUND: Benign paroxysmal positional vertigo is classified into five subtypes according to the features of positional nystagmus: lateral canalolithiasis, lateral light cupula, lateral heavy cupula, posterior canalolithiasis and posterior heavy cupula. OBJECTIVES: The first aim of the study was to clarify whether the lateral canal type or posterior canal type was more common. The second aim of the study was to assess the aetiology of benign paroxysmal positional vertigo by investigating the onset time of each subtype. METHODS: The subjects were 512 consecutive patients with benign paroxysmal positional vertigo. The patients were prospectively aggregated, and interviews were used to evaluate onset time. RESULTS: The lateral canal type (55.5 per cent) was more common than the posterior canal type (44.5 per cent). Time of awakening was the most common onset time in every subtype. CONCLUSION: The incidence of lateral canal type is higher than that of posterior canal type. The aetiology of benign paroxysmal positional vertigo is closely related to sleep.
Subject(s)
Benign Paroxysmal Positional Vertigo/classification , Benign Paroxysmal Positional Vertigo/diagnosis , Nystagmus, Physiologic/physiology , Otolithic Membrane/physiopathology , Arousal/physiology , Benign Paroxysmal Positional Vertigo/epidemiology , Benign Paroxysmal Positional Vertigo/etiology , Female , Humans , Incidence , Interviews as Topic , Male , Middle Aged , Prospective Studies , Semicircular Canals/physiopathology , Sleep/physiology , Time Factors , Vestibular Function Tests/methodsABSTRACT
OBJECTIVE: To describe a case of benign paroxysmal positional vertigo (BPPV) resulting in reversible horizontal semicircular canalith jam successfully treated with horizontal canal occlusion. A brief literature review of similar cases was performed. METHODS: Case report and literature review. RESULTS: A 68-year-old female presented with apogeotropic positional nystagmus, attributed to reversible horizontal canalith jam mimicking cupulolithiasis that was refractory to tailored repositioning maneuvers across months. She was unable to work due to the severity of her symptoms. She underwent surgical occlusion of the affected canal with immediate resolution of her symptoms. A literature review revealed similar cases of canalith jam mimicking cupulolithiasis. CONCLUSIONS: Reversible canalith jam, in which particles moving with horizontal head position alternate between obstructing the semicircular canal and resting on the cupula, can mimic signs of cupulolithiasis. This variant of BPPV can be effectively managed with surgical canal occlusion should symptoms fail to resolve after tailored repositioning maneuvers.
Subject(s)
Benign Paroxysmal Positional Vertigo , Labyrinthitis , Otolithic Membrane , Semicircular Canals , Vestibular Diseases/diagnosis , Aged , Benign Paroxysmal Positional Vertigo/diagnosis , Benign Paroxysmal Positional Vertigo/etiology , Benign Paroxysmal Positional Vertigo/physiopathology , Benign Paroxysmal Positional Vertigo/surgery , Diagnosis, Differential , Diagnostic Techniques, Otological , Female , Humans , Labyrinthitis/diagnosis , Labyrinthitis/physiopathology , Labyrinthitis/surgery , Lithiasis/diagnosis , Otolithic Membrane/pathology , Otolithic Membrane/physiopathology , Otologic Surgical Procedures/methods , Semicircular Canals/pathology , Semicircular Canals/surgery , Treatment OutcomeABSTRACT
Importance: Video-oculography (VOG) goggles have been integrated into the assessment of semicircular canal function in patients with vestibular disorders. However, a similar bedside VOG method for testing otolith function is lacking. Objective: To evaluate the use of VOG-based measurement of ocular counter-roll (vOCR) as a clinical test of otolith function. Design, Setting, and Participants: A case-control study was conducted to compare vOCR measurement among patients at various stages of unilateral loss of vestibular function with healthy controls. The receiver operating characteristic curve method was used to determine the diagnostic accuracy of the vOCR test in detecting loss of otolith function. Participants were recruited at a tertiary center including the Johns Hopkins outpatient clinic and Johns Hopkins Hospital, Baltimore, Maryland. Participants included 56 individuals with acute (≤4 weeks after surgery), subacute (4 weeks-6 months after surgery), and chronic (>6 months after surgery) unilateral vestibular loss as well as healthy controls. A simple bedside maneuver with en bloc, 30° lateral tilt of the head and trunk was used for vOCR measurement. The study was conducted from February 2, 2017, to March 10, 2019. Intervention: In each participant vOCR was measured during static tilts of the head and trunk en bloc. Main Outcomes and Measures: The vOCR measurements and diagnostic accuracy of vOCR in detecting patients with loss of vestibular function from healthy controls. Results: Of the 56 participants, 28 (50.0%) were men; mean (SD) age was 53.5 (11.4) years. The mean (SD) time of acute unilateral vestibular loss was 9 (7) days (range, 2-17 days) in the acute group, 61 (39) days (range, 28-172 days) in the subacute group, and 985 (1066) days (range 185-4200 days) in the chronic group. The vOCR test showed reduction on the side of vestibular loss, and the deficit was greater in patients with acute and subacute vestibular loss than in patients with chronic loss and healthy controls (acute vs chronic: -1.81°; 95% CI, -3.45° to -0.17°; acute vs control: -3.18°; 95% CI, -4.83° to -1.54°; subacute vs chronic: -0.63°; 95% CI, -2.28° to 1.01°; subacute vs control: -2.01°; 95% CI, -3.65° to -0.36°; acute vs subacute: -1.17°; 95% CI, -2.88° to 0.52°; and chronic vs control: -1.37°; 95% CI, -2.96° to 0.21°). The asymmetry in vOCR between the side of vestibular loss and healthy side was significantly higher in patients with acute vs chronic loss (0.28; 95% CI, 0.06-0.51). Overall, the performance of the vOCR test in discriminating between patients with vestibular loss and healthy controls was 0.83 (area under the receiver operating characteristic curve). The best vOCR threshold to detect vestibular loss at the 30° tilt was 4.5°, with a sensitivity of 80% (95% CI, 0.62%-0.88%) and specificity of 82% (95% CI, 0.57%-1.00%). Conclusions and Relevance: The findings of this case-control study suggest that the vOCR test can be performed with a simple bedside maneuver and may be used to detect or track loss of otolith function.
Subject(s)
Otolithic Membrane/physiopathology , Vestibular Diseases/diagnosis , Vestibular Diseases/physiopathology , Vestibular Function Tests/methods , Case-Control Studies , Female , Head Movements , Humans , Male , Middle AgedABSTRACT
BACKGROUND: The graviceptive otolith function can be measured using subjective visual horizontal (SVH) testing. Nevertheless, more research efforts are required to understand the essential variables affecting SVH. OBJECTIVE: The aim of the present study was to determine the effects of type of visual image and gender on subjective visual horizontal (SVH) perception among healthy adults. MATERIALS AND METHODS: In this comparative study, 50 healthy young adults were enrolled. While in an upright body position, they were required to report their perception of horizontality for two types of visual images (solid line and arrow pattern) using a computerized SVH device. RESULTS: The arrow pattern produced significantly bigger SVH angles than the solid line (p < .001). In contrast, no significant influence of gender was found on SVH results (p = .743), Based on the statistical outcomes, the preliminary normative data for SVH were established. CONCLUSIONS AND SIGNIFICANCE: The arrow pattern (a more complex visual image) produced bigger SVH deviations than the simple solid line image. In contrast, the horizontality perception does not appear to be affected by gender. The preliminary normative SVH data gathered from the present study can be beneficial for clinical and future research applications.
Subject(s)
Otolithic Membrane/physiopathology , Space Perception/physiology , Vestibular Function Tests/methods , Vestibule, Labyrinth/physiopathology , Visual Perception/physiology , Female , Healthy Volunteers , Humans , Male , Sex Factors , Young AdultABSTRACT
OBJECTIVE: Motion sickness (MS) is a familiar condition to scuba divers. The purpose of this study was to compare otolith organ function of scuba divers who have MS to those without MS. METHOD: Video-oculography (VOG) goggles were used to measure video ocular counter-roll (vOCR) in 50 healthy scuba divers with no vestibular pathology. Divers with MS (n = 30) had Graybiel motion sickness (GMS) scores of ≥1 point, and divers without MS (n = 20) had GMS scores of 0. Divers with MS also completed the Motion Sickness Susceptibility Questionnaire short form (MSSQs). For all divers, otolith-ocular function of both ears was tested separately via vOCR testing, which was performed during 30° head tilt. An R-L side asymmetry ratio for vOCR values (%OCRA) was compared to divers' static OCR. RESULTS: MSSQs and %OCRA scores differed significantly (p<0.01and p<0.001, respectively) between divers with MS and divers without MS. Their %OCRA scores and severity of MS were significantly correlated. Female divers were more susceptible to MS. ROC analysis for %OCRA revealed that the AUC for divers with MS and divers without MS was 0.8967 (95% CI, 0.8114 to 0.9819), the specificity was 1.000, and the sensitivity was 0.700, with a cutoff value of 45.946. CONCLUSION: Physiological differences between R-L otolith organ function could affect the severity and susceptibility to MS. Female hormones may also increase susceptibility to MS. Thus, MS may be a physiological phenomenon induced by functional ear differences in the absence of pathology. As MS is caused by multiple factors, otolaryngologists need to consider various causative factors beyond those related to otolith organ function in scuba divers with MS.
Subject(s)
Diving/physiology , Eye Movements/physiology , Motion Sickness/physiopathology , Otolithic Membrane/physiology , Reflex, Vestibulo-Ocular/physiology , Adult , Female , Humans , Male , Middle Aged , Motion Sickness/etiology , Otolithic Membrane/physiopathology , ROC CurveABSTRACT
OBJECTIVES: Obstructive sleep apnea (OSA) is a common sleep disorder, which is associated with recurrent oxygen desaturation during sleep. It has already been shown that nocturnal hypoxia may lead to cochlear dysfunction in patients with OSA. Less is known whether hypoxia during sleep also impacts vestibular function in those patients. Thus, the aim of the presented study was to assess a potential vestibulotoxic effect of nightly desaturations with hypoxia in patients with OSA by investigating a possible correlation between respiratory parameters and vestibular function tests. METHODS: A total of 56 patients were included in the study and underwent a fully attended cardiorespiratory polysomnography (PSG). Vestibular function was assessed using video head impulse test to evaluate horizontal semicircular canal function and cervical vestibular evoked myogenic potentials (cVEMPs) and ocular vestibular evoked myogenic potentials (oVEMPs) to measure otolith function. Descriptive data analysis was conducted and correlation analysis between selected PSG parameters and the results of vestibular testing was performed using Kendall τ coefficient. RESULTS: A significant correlation between vestibular function and respiratory polysomnographic parameters could not be demonstrated in the study (P > .05) but cVEMP and oVEMP results showed a trend toward a correlation with oxygen desaturation indices and apnea-hypopnea index. Additionally, otolith hypofunction was more prevalent in patients with hypertension as well as OSA. CONCLUSION: The results of our study show that there is no significant correlation between vestibular function and sleep apnea parameters, although otolith dysfunction might be more prevalent in patients with OSA and hypertension.
Subject(s)
Hypoxia/physiopathology , Otolithic Membrane/physiopathology , Sleep Apnea, Obstructive/complications , Adult , Age Distribution , Aged , Aged, 80 and over , Ear, Inner , Female , Head Impulse Test , Humans , Hypoxia/etiology , Male , Middle Aged , Polysomnography , Sleep Apnea, Obstructive/physiopathology , Vestibular Diseases/physiopathology , Vestibular Evoked Myogenic Potentials/physiologyABSTRACT
BACKGROUND: Only a few studies in the literature demonstrate the effect of vestibular rehabilitation (VR) on all vestibular receptor organs. Furthermore, very little evidence of the effect of VR on isolated otolith dysfunction (IOD) is available. OBJECTIVE: The study aimed to investigate the effect of VR on all vestibular receptor organs in patients with different types of unilateral vestibular hypofunction (UVH). METHODS: We enrolled 80 patients with three different types of UVH; combined and isolated loss of semicircular canal and otolith organ function. All patients performed a 12-week customized program of VR and received a full battery of vestibular function tests, before and after the VR. The DHI and SF-36 were performed before, after 6 weeks, and 12 weeks of the VR. RESULTS: Parameters of the caloric test, video head impulse test, ocular and cervical vestibular evoked myogenic potentials were significantly improved after VR. A total of 59 (74%) patients fully recovered, with no significant difference in recovery regarding the type (pâ=â0.13) and stage of UVH (pâ=â0.13). All patients reported significantly lower disability and a better quality of life after the VR based on the DHI and SF-36 score. CONCLUSIONS: Vestibular rehabilitation has a positive effect on the recovery of all vestibular receptor organs and it should be used in patients with IOD.
Subject(s)
Exercise Therapy/methods , Otolithic Membrane/physiology , Recovery of Function/physiology , Semicircular Canals/physiology , Vestibular Diseases/rehabilitation , Vestibule, Labyrinth/physiology , Adult , Caloric Tests/methods , Caloric Tests/psychology , Female , Humans , Male , Middle Aged , Otolithic Membrane/physiopathology , Quality of Life/psychology , Semicircular Canals/physiopathology , Vestibular Diseases/physiopathology , Vestibular Diseases/psychology , Vestibular Evoked Myogenic Potentials/physiology , Vestibular Function Tests/methods , Young AdultABSTRACT
OBJECTIVE: To separate vestibular neuritis (VN) from posteriorcirculation stroke (PCS) using quantitative tests of canal and otolith function. METHODS: Video Head-Impulse tests (vHIT) were used to assess all three semicircular canal pairs; vestibulo-ocular reflex (VOR) gain and saccade metrics were examined. Cervical and ocular-Vestibular-Evoked Myogenic Potentials (c- and oVEMP) and Subjective Visual Horizontal (SVH) were used to assess otolith function. RESULTS: For controls (n = 40), PCS (n = 22), and VN (n = 22), mean horizontal-canal VOR-gains were 0.96 ± 0.1, 0.85 ± 0.3 and 0.40 ± 0.2, refixation-saccade prevalence was 71.9 ± 41, 90.7 ± 57, 209.2 ± 62 per 100 impulses and cumulative-saccade amplitudes were 0.9 ± 0.4°, 2.4 ± 2.2°, 8.0 ± 3.5°. Abnormality-rates for cVEMP, oVEMP and SVH were 38%, 9%, 72% for PCS, and 43%, 50%, 91% for VN. A gain ≤0.68, refixation-saccade prevalence of ≥135% and cumulative-saccade amplitudes ≥5.3° separated VN from PCS with sensitivities of 95.5%, 95.5%, and 81.8%, and specificities of 68.2%, 86.4% and 95.5%. VOR-gain and saccade prevalence when combined, separated VN from PCS with a sensitivity and specificity of 90.9%. Abnormal oVEMP asymmetry-ratios were of low sensitivity (50%) but high specificity (90.9%) for separating VN from PCS. CONCLUSION: vHIT provided the best separation of VN from PCS. VOR-gain, refixation-saccade prevalence and amplitude were effective discriminators of VN from PCS. SIGNIFICANCE: vHIT and oVEMP could assist early identification of the aetiology of Acute Vestibular Syndrome in the Emergency Room.
Subject(s)
Head Impulse Test/methods , Stroke/diagnosis , Vestibular Neuronitis/diagnosis , Diagnosis, Differential , Head Impulse Test/standards , Humans , Otolithic Membrane/physiopathology , Reflex, Vestibulo-Ocular , Sensitivity and Specificity , Stroke/physiopathology , Vestibular Evoked Myogenic Potentials , Vestibular Neuronitis/physiopathologyABSTRACT
Benign paroxysmal positional vertigo (BPPV) represents the most common form of positional vertigo. It is caused by dislodged otoconia that freely float in the semicircular canals (canalolithiasis) or attach to the cupula (cupulolithiasis). A cupulolithiasis-type (or a heavy cupula-type) of BPPV implicating the lateral semicircular canal (LSCC) exhibits persistent ageotropic direction-changing positional nystagmus (DCPN) in a head-roll test. However, in some cases, unlike any type of BPPV, persistent geotropic DCPN cannot be explained by any mechanisms of BPPV, and don't fit the current classifications. Recently, the notion of light cupula has been introduced to refer to the persistent geotropic DCPN. In this study, we looked at the clinical features of light cuplula and discussed the possible mechanisms and therapeutic strategies of the condition. The notion of light cupula is a helpful addition to the theory of peripheral positional vertigo and nystagmus.
Subject(s)
Benign Paroxysmal Positional Vertigo/physiopathology , Nystagmus, Physiologic/physiology , Otolithic Membrane/physiopathology , Semicircular Canals/physiopathology , HumansABSTRACT
Objectives: To examine the effects of unilateral cochlear implantation on the balance system for adult patients with bilateral severe to profound sensory neural hearing loss. Methods: 7 CI candidates. The function of the sacculus, utricle, and three semi-circular canals (SCCs) was assessed separately using air conduction cervical vestibular evoked myogenic potentials (VEMP), vibration ocular VEMP and the video head impulse test (vHIT) respectively on each side, pre- and post-operatively. Results: The Otoliths appear more affected by implantation than SCCs. In 3 of 7 cases VEMP was affected by implantation. In 2 cases this was associated with short-term dizziness. Discussion: Differential assessment of vestibular end organ function may elucidate how cochlear implantation affects the vestibular system. As many CI candidates have some vestibular function, pre-implant vestibular assessment may help to inform which side of implantation may best preserve that function if other audiology and surgical considerations are equal. Post-implant assessment with VEMP may help to predict short-term dizziness. More work with a larger sample will be needed to make the case for routine clinical assessment. Conclusions: There is potential benefit of conducting multimodal vestibularassessment pre and post cochlear implantation. The otoliths appear more affected by implantation than the SCC.
Subject(s)
Cochlear Implantation/adverse effects , Dizziness/diagnosis , Hearing Loss, Sensorineural/surgery , Postoperative Complications/diagnosis , Vestibular Diseases/diagnosis , Adolescent , Adult , Cochlear Implantation/methods , Dizziness/etiology , Female , Hearing Loss, Sensorineural/physiopathology , Humans , Male , Middle Aged , Otolithic Membrane/physiopathology , Postoperative Complications/etiology , Treatment Outcome , Vestibular Diseases/etiology , Vestibular Evoked Myogenic Potentials , Vestibular Function Tests , Young AdultABSTRACT
The accurate differentiation of the subtypes of benign paroxysmal positional vertigo (BPPV) can significantly improve the efficacy of repositioning maneuver in its treatment and thus reduce unnecessary clinical tests and inappropriate medications. In this study, attempts have been made towards developing approaches of causality modeling and diagnostic reasoning about the uncertainties that can arise from medical information. A dynamic uncertain causality graph-based differential diagnosis model for BPPV including 354 variables and 885 causality arcs is constructed. New algorithms are also proposed for differential diagnosis through logical and probabilistic inference, with an emphasis on solving the problems of intricate and confounding disease factors, incomplete clinical observations, and insufficient sample data. This study further uses vertigo cases to test the performance of the proposed method in clinical practice. The results point to high accuracy, a satisfactory discriminatory ability for BPPV, and favorable robustness regarding incomplete medical information. The underlying pathological mechanisms and causality semantics are verified using compact graphical representation and reasoning process, which enhance the interpretability of the diagnosis conclusions.
Subject(s)
Algorithms , Benign Paroxysmal Positional Vertigo/diagnosis , Diagnosis, Computer-Assisted/methods , Benign Paroxysmal Positional Vertigo/classification , Benign Paroxysmal Positional Vertigo/therapy , Causality , Computational Biology , Computer Graphics , Diagnosis, Computer-Assisted/statistics & numerical data , Diagnosis, Differential , Humans , Models, Biological , Otolithic Membrane/physiopathology , Patient Positioning , Semicircular Canals/physiopathology , UncertaintyABSTRACT
The 'Bow and Lean Test' (BLT) was developed for proper diagnosis of horizontal semicircular canal benign paroxysmal positional vertigo (HSC-BPPV). Occasionally, down- and/or up-beating vertical nystagmus is observed during the BLT. This study analyzed patients who exhibited vertical nystagmus in the BLT to comprehend the clinical significance of this sign. Of 2872 patients with vertigo between 2010 and 2015, 225 patients who showed vertical nystagmus in the BLT were enrolled. All patterns of vertical nystagmus were described based on their types of BPPV. After performing therapeutic maneuvers for BPPV, remnant symptoms in the BLT findings were investigated. Of the 225 patients with vertical nystagmus, 163 were posterior semicircular canal BPPV (PSC-BPPV). Down-beating in the bowing position and no nystagmus in the leaning position ('Down/-') was the most common type (190 of 225 patients). In addition, the nystagmus occurred in the form of '-/Up', 'Down/Up', and '-/Down'. The pattern of vertical nystagmus may be related to the position of otoconia in the canals. The location of the otoconia enables the diagnosis of hidden PSC-BPPV. Even after treatment for BPPV, patients with vertical nystagmus in the BLT tended to complain remnant vertigo symptoms (44.8% vs. 23.9%, P = 0.022, in PSC-BPPV; 70.0% vs. 24.0%, P = 0.020, in HSC-BPPV). We thought that they actually had hidden PSC-BPPV and the otoconial debris may still in the PSC; this untreated PSC-BPPV might cause the remnant symptoms. In conclusion, vertical nystagmus in the BLT may indicate the presence of PSC-BPPV. Moreover, vertical nystagmus during the BLT may occur in patients with hidden PSC-BPPV who complain of remnant vertigo symptoms. Vertical nystagmus shown in the BLT may not include the possibility of central vertigo.
Subject(s)
Benign Paroxysmal Positional Vertigo/diagnosis , Canaliculitis/diagnosis , Nystagmus, Pathologic/diagnosis , Benign Paroxysmal Positional Vertigo/physiopathology , Canaliculitis/physiopathology , Dizziness/physiopathology , Female , Humans , Male , Nystagmus, Pathologic/physiopathology , Otolithic Membrane/physiopathology , Posture/physiology , Semicircular Canals/physiopathology , Semicircular Ducts/physiopathologyABSTRACT
Major earthquakes occasionally cause vertiginous attacks or persistent dizziness, which may be related to the effects of autonomic stress on equilibrium function and/or psychological factors. We present the case of a 73-year-old woman who suffered from persistent dizziness for 1 year, during which she lived in a house tilted by the great 2011 Tohoku earthquake. An electronystagmogram demonstrated leftward horizontal and downbeat nystagmus in the sitting and supine positions with eyes closed. Caloric testing and cervical vestibular-evoked myogenic potentials showed normal responses in both ears. Posturography indicated no involvement of psychological factors or autonomic stress. After moving into a new apartment, both the dizziness and nystagmus completely disappeared within 10 weeks. We speculate that the gravity-related linear acceleration with vertical and horizontal components in the tilted house may have chronically stimulated the otoliths, inducing the symptoms and nystagmus via the velocity storage mechanism.
Subject(s)
Dizziness/etiology , Earthquakes , Gravitation , Nystagmus, Pathologic/etiology , Otolithic Membrane/physiopathology , Aged , Electronystagmography , Female , Humans , Supine PositionABSTRACT
OBJECTIVES/HYPOTHESIS: We conducted this study to assess the effects of unilateral cochlear implantation (CI) on otolith function by observing the changes in ocular vestibular evoked myogenic potential (oVEMP) and cervical vestibular evoked myogenic potential (cVEMP) in children. STUDY DESIGN: Prospective case series. METHODS: The oVEMP and cVEMP elicited by air-conducted sound in 35 children were analyzed preoperatively and at 5 days, 1 month, and 2 months after surgery. RESULTS: Before CI, the response rates of oVEMPs and cVEMPs were 81.4% and 91.4%, respectively. In the implanted side, oVEMPs and cVEMPs were reduced by 37.1% and 68.6%, respectively, 5 days after CI. One month after CI, oVEMPs and cVEMPs were 34.6% and 72%, respectively, with the device switched off, and 50% and 73.1%, respectively, with the device switched on. Two months after CI, the oVEMPs and cVEMPs were 36% and 80%, respectively, when the implant was turned off, and 70.8% and 75%, respectively, when the implant was turned on. CONCLUSIONS: The study confirmed the value of VEMP testing in the clinical setting and that absent VEMPs could indicate impairment of otolith function after CI. LEVEL OF EVIDENCE: 4 Laryngoscope, 2020.
Subject(s)
Cochlear Implantation , Otolithic Membrane/physiopathology , Vestibular Evoked Myogenic Potentials , Child , Child, Preschool , Female , Humans , Male , Prospective StudiesABSTRACT
Abnormal formation of otoconia, the biominerals of the inner ear, results in balance disorders. The inertial mass of otoconia activates the underlying mechanosensory hair cells in response to change in head position primarily during linear and rotational acceleration. Otoconia associate exclusively with the two gravity receptors, the utricle and saccule. The cristae sensory epithelium is associated with an extracellular gelatinous matrix known as cupula, equivalent to otoconia. During head rotation, the inertia of endolymphatic fluids within the semicircular canals deflects the cupula of the corresponding crista and activates the underlying mechanosensory hair cells. It is believed that detached free-floating otoconia particles travel ectopically to the semicircular canal and cristae and are the culprit for benign paroxysmal positional vertigo (BPPV). The Slc26a4 mouse mutant harbors a missense mutation in pendrin. This mutation leads to impaired transport activity of pendrin and to defects in otoconia composition and distribution. All Slc26a4 loop/loop homozygous mutant mice are profoundly deaf but show inconsistent vestibular deficiency. A panel of behavioral tests was utilized in order to generate a scoring method for vestibular function. A pathological finding of displaced otoconia was identified consistently in the inner ears of mutant mice with severe vestibular dysfunction. In this work, we present a mouse model with a genetic predisposition for ectopic otoconia with a clinical correlation to BPPV. This unique mouse model can serve as a platform for further investigation of BPPV pathophysiology, and for developing novel treatment approaches in a live animal model.
Subject(s)
Benign Paroxysmal Positional Vertigo/genetics , Otolithic Membrane/metabolism , Sulfate Transporters/genetics , Animals , Benign Paroxysmal Positional Vertigo/physiopathology , Female , Genetic Predisposition to Disease , Homozygote , Male , Mice , Mutation , Otolithic Membrane/physiopathology , Sulfate Transporters/metabolismABSTRACT
PURPOSE OF REVIEW: To examine the recent literature concerning the neural basis and clinical evidence for the response of the labyrinth to sound and vibration: vestibular-evoked myogenic potentials (VEMPs) and vibration-induced nystagmus (VIN). RECENT FINDINGS: There are two streams of information from each otolith - a sustained stream (afferents with regular resting activity, signalling gravity and low-frequency linear accelerations) and a transient stream (afferents with irregular resting activity) signalling onset of linear acceleration, and sound and vibration. These irregular neurons are synchronized to each cycle of the stimulus. Neurons in the transient stream are tested by presenting sounds or vibration (500âHz) and using surface electrodes to measure myogenic potentials from muscles activated by otolithic stimuli (VEMPs). 100âHz vibration activates irregular canal afferents and causes a stimulus-locked VIN in patients with asymmetric canal function. These new tests of the transient system have one big advantage over older tests of the sustained system - they reliably show the effect of long-term unilateral vestibular loss. SUMMARY: The new physiological and anatomical evidence shows how sound and vibration activate otolith and canal receptors and so provides the scientific foundation for VEMPs and VIN, which are important tools for diagnosing vestibular disorders. VIDEO ABSTRACT: http://links.lww.com/CONR/A47.
Subject(s)
Otolithic Membrane/physiopathology , Vestibular Diseases/diagnosis , Vestibular Evoked Myogenic Potentials/physiology , Vestibule, Labyrinth/physiopathology , Acoustic Stimulation , Humans , Neurons/physiology , Vestibular Diseases/physiopathology , VibrationABSTRACT
INTRODUCTION: Bilateral vestibulopathy is an important cause of imbalance that is misdiagnosed. The clinical management of patients with bilateral vestibular loss remains difficult as there is no clear evidence for an effective treatment. In this paper, we try to analyze the effect of chronic electrical stimulation and adaptation to electrical stimulation of the vestibular system in humans when stimulating the otolith organ with a constant pulse train to mitigate imbalance due to bilateral vestibular dysfunction (BVD). METHODS: We included 2 patients in our study with BVD according to Criteria Consensus of the Classification Committee of the Bárány Society. Both cases were implanted by using a full-band straight electrode to stimulate the otoliths organs and simultaneously for the cochlear stimulation we use a perimodiolar electrode. RESULTS: In both cases Vestibular and clinical test (video head impulse test, videonistagmography cervical vestibular evoked myogenic potentials, cVEMP and oVEMP), subjective visual vertical test, computerized dynamic posturography, dynamic gait index, Time UP and Go test and dizziness handicap index) were performed. Posture and gait metrics reveal important improvement if compare with preoperartive situation. Oscillopsia, unsteadiness, independence and quality of life improved to almost normal situation. DISCUSSION/CONCLUSION: Prosthetic implantation of the otolith organ in humans is technically feasible. Electrical stimulation might have potential effects on balance and this is stable after 1 year follow-up. This research provides new possibilities for the development of vestibular implants to improve gravito-inertial acceleration sensation, in this case by the otoliths stimulation.