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1.
J Neurotrauma ; 38(16): 2291-2300, 2021 08 15.
Article in English | MEDLINE | ID: mdl-33752455

ABSTRACT

Combat sports pose a risk for accumulative injuries to the nervous system, yet fighters have remained an understudied population. Here, our purpose was to determine whether repetitive blows to the head have an effect on vestibular balance reflexes in combat sports athletes. We compared lower-limb muscle responses evoked with electrical vestibular stimuluation (EVS) between fighters (boxing/muay thai) and non-fighter controls. Each participant received stochastic vestibular stimulation (0-25 Hz, ±3 mA) over their mastoid processes while they stood relaxed with their head to the left or right. Surface electromyography was recorded from the medial gastrocnemius and soleus muscles bilaterally. Short and medium latency response (SLR/MLR) peaks were significantly delayed in the fighter group compared to controls. SLR and MLR peak amplitudes were also significantly lower in fighters. Fighter-estimated cumulative repetitive head impact (RHI) events demonstrated strong positive correlations with the timing of SLR and MLR peaks. Cumulative RHI events also negatively correlated with peak MLR amplitude and response gain at frequencies above 5 Hz. Our results provide evidence of a progressive vestibular impairment in combat sports athletes, potentially resulting from blows to the head accumulated in sparring practice and competitive bouts throughout their careers. Taken together, EVS-based vestibular assessments may provide a valuable clinical diagnostic tool and help better inform "return-to-play" and career-length decisions for not only combat sports athletes, but potentially other populations at risk of RHIs.


Subject(s)
Boxing/injuries , Craniocerebral Trauma/physiopathology , Martial Arts/injuries , Postural Balance/physiology , Vestibular Evoked Myogenic Potentials/physiology , Vestibule, Labyrinth/physiopathology , Adult , Case-Control Studies , Electric Stimulation , Female , Humans , Lower Extremity , Male , Middle Aged , Muscle, Skeletal/physiopathology , Reaction Time , Young Adult
2.
Am J Otolaryngol ; 41(6): 102609, 2020.
Article in English | MEDLINE | ID: mdl-32615473

ABSTRACT

PURPOSE: This study investigated the feasibility of acceptance and commitment therapy for persistent postural-perceptual dizziness and preliminarily verified the long-term effectiveness of the therapy. MATERIALS AND METHODS: This study implemented the within-group pre-post comparison design. We enrolled 27 adult patients who met the criteria of persistent postural-perceptual dizziness. They underwent a treatment program including acceptance and commitment therapy combined with vestibular rehabilitation once a week for a total of six sessions. The primary outcome was changes in the Dizziness Handicap Inventory score 6 months posttreatment. RESULTS: All 27 patients completed the acceptance and commitment therapy + vestibular rehabilitation program, and 25 patients (92.6%) could be followed for 6 months posttreatment. For 27 participants, the scores from pretreatment to 6 months posttreatment significantly declined (P < .001), and the Dizziness Handicap Inventory effect size was 1.11 (95% confidence interval = 0.80-1.42). At 6 months posttreatment, 11 patients (40.7%) achieved remission (the score ≤ 14), 16 (59.3%) achieved treatment response (reduction in the score ≥ 18), and 20 (74.1%) achieved remission and/or treatment response. CONCLUSIONS: Acceptance and commitment therapy is feasible for persistent postural-perceptual dizziness and might have long-term effectiveness. However, a randomized controlled trial is warranted.


Subject(s)
Acceptance and Commitment Therapy/methods , Dizziness/rehabilitation , Dizziness/therapy , Neurological Rehabilitation/methods , Pilot Projects , Vestibular Diseases/rehabilitation , Vestibular Diseases/therapy , Vestibule, Labyrinth/physiopathology , Dizziness/etiology , Feasibility Studies , Humans , Motion Perception/physiology , Postural Balance/physiology , Time Factors , Treatment Outcome , Vestibular Diseases/complications
3.
Audiol Neurootol ; 25(1-2): 6-24, 2020.
Article in English | MEDLINE | ID: mdl-31533097

ABSTRACT

BACKGROUND: In patients with bilateral vestibulopathy, the regular treatment options, such as medication, surgery, and/or vestibular rehabilitation, do not always suffice. Therefore, the focus in this field of vestibular research shifted to electrical vestibular stimulation (EVS) and the development of a system capable of artificially restoring the vestibular function. Key Message: Currently, three approaches are being investigated: vestibular co-stimulation with a cochlear implant (CI), EVS with a vestibular implant (VI), and galvanic vestibular stimulation (GVS). All three applications show promising results but due to conceptual differences and the experimental state, a consensus on which application is the most ideal for which type of patient is still missing. SUMMARY: Vestibular co-stimulation with a CI is based on "spread of excitation," which is a phenomenon that occurs when the currents from the CI spread to the surrounding structures and stimulate them. It has been shown that CI activation can indeed result in stimulation of the vestibular structures. Therefore, the question was raised whether vestibular co-stimulation can be functionally used in patients with bilateral vestibulopathy. A more direct vestibular stimulation method can be accomplished by implantation and activation of a VI. The concept of the VI is based on the technology and principles of the CI. Different VI prototypes are currently being evaluated regarding feasibility and functionality. So far, all of them were capable of activating different types of vestibular reflexes. A third stimulation method is GVS, which requires the use of surface electrodes instead of an implanted electrode array. However, as the currents are sent through the skull from one mastoid to the other, GVS is rather unspecific. It should be mentioned though, that the reported spread of excitation in both CI and VI use also seems to induce a more unspecific stimulation. Although all three applications of EVS were shown to be effective, it has yet to be defined which option is more desirable based on applicability and efficiency. It is possible and even likely that there is a place for all three approaches, given the diversity of the patient population who serves to gain from such technologies.


Subject(s)
Electric Stimulation Therapy , Vestibular Diseases/therapy , Vestibule, Labyrinth/physiopathology , Cochlear Implantation , Electrodes, Implanted , Humans , Reflex, Vestibulo-Ocular/physiology , Vestibular Diseases/physiopathology
4.
Curr Opin Neurol ; 33(1): 126-135, 2020 02.
Article in English | MEDLINE | ID: mdl-31789675

ABSTRACT

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 (500 Hz) and using surface electrodes to measure myogenic potentials from muscles activated by otolithic stimuli (VEMPs). 100 Hz 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 , Vibration
5.
Audiol Neurootol ; 25(1-2): 79-90, 2020.
Article in English | MEDLINE | ID: mdl-31801137

ABSTRACT

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.


Subject(s)
Bilateral Vestibulopathy/therapy , Electric Stimulation Therapy , Hearing Loss, Sensorineural/therapy , Otolithic Membrane/physiopathology , Adult , Bilateral Vestibulopathy/physiopathology , Gait/physiology , Head Impulse Test , Hearing Loss, Sensorineural/physiopathology , Humans , Male , Middle Aged , Postural Balance/physiology , Quality of Life , Time and Motion Studies , Vestibular Evoked Myogenic Potentials/physiology , Vestibule, Labyrinth/physiopathology
6.
Audiol Neurootol ; 25(1-2): 91-95, 2020.
Article in English | MEDLINE | ID: mdl-31661687

ABSTRACT

INTRODUCTION: The vestibular implant could become a clinically useful device in the near future. This study investigated the feasibility of restoring the high-frequency dynamic visual acuity (DVA) with a vestibular implant, using the functional Head Impulse Test (fHIT). METHODS: A 72-year-old female, with bilateral vestibulopathy and fitted with a modified cochlear implant incorporating three vestibular electrodes (MED-EL, Innsbruck, Austria), was available for this study. Electrical stimulation was delivered with the electrode close to the lateral ampullary nerve in the left ear. The high-frequency DVA in the horizontal plane was tested with the fHIT. After training, the patient underwent six trials of fHIT, each with a different setting of the vestibular implant: (1) System OFF before stimulation; (2) System ON, baseline stimulation; (3) System ON, reversed stimulation; (4) System ON, positive stimulation; (5) System OFF, without delay after stimulation offset; and (6) System OFF, 25 min delay after stimulation offset. The percentage of correct fHIT scores for right and left head impulses were compared between trials. RESULTS: Vestibular implant stimulation improved the high-frequency DVA compared to no stimulation. This improvement was significant for "System ON, baseline stimulation" (p = 0.02) and "System ON, positive stimulation" (p < 0.001). fHIT scores changed from 19 to 44% (no stimulation) to maximum 75-94% (System ON, positive stimulation). CONCLUSION: The vestibular implant seems capable of improving the high-frequency DVA. This functional benefit of the vestibular implant illustrates again the feasibility of this device for clinical use in the near future.


Subject(s)
Bilateral Vestibulopathy/therapy , Cochlear Implants , Electric Stimulation Therapy , Vestibule, Labyrinth/physiopathology , Visual Acuity/physiology , Aged , Austria , Bilateral Vestibulopathy/physiopathology , Female , Head Impulse Test , Humans , Treatment Outcome , Vestibular Nerve/physiopathology
7.
Eur Arch Otorhinolaryngol ; 276(7): 1951-1959, 2019 Jul.
Article in English | MEDLINE | ID: mdl-31053967

ABSTRACT

PURPOSE: Although the cochlear implantation procedure does not interfere with vestibular structures directly, both the vestibulum and the cochlea share the same inner ear fluid space, and this fluid may be responsible for transferring possibly damaging forces from one to the other. The purpose of the study is to assess postoperative vestibular function after partial deafness treatment-electro-acoustic stimulation (PDT-EAS) cochlear implantation. METHODS: Fifty-five patients were included in the study (30 females, 25 males, age 11-80, mean 41.8 ± 19.35). cVEMP and oVEMP were performed preoperatively and 1-3 months after cochlear implantation. Caloric and vHIT tests were conducted preoperatively and 4-6 months after cochlear implantation. RESULTS: Our study shows that, based on a wide range of electrodes, use of PDT-EAS is protective in terms of preserving vestibular function. It gives a rate of saccular damage of 15.79%, utricular damage of 19.04%, and a horizontal semicircular canal response reduction of 15.79%. CONCLUSIONS: PDT-EAS is protective in terms of preserving vestibular function. Nevertheless, it should be emphasized that the risk of vestibular damage cannot be totally eliminated even when hearing preservation techniques are adopted.


Subject(s)
Acoustic Stimulation/methods , Cochlea/physiopathology , Cochlear Implantation , Deafness/surgery , Postoperative Complications , Vestibule, Labyrinth/physiopathology , Adult , Cochlear Implantation/adverse effects , Cochlear Implantation/methods , Deafness/diagnosis , Deafness/physiopathology , Female , Hearing Tests/methods , Humans , Male , Middle Aged , Postoperative Complications/diagnosis , Postoperative Complications/physiopathology , Prospective Studies , Recovery of Function , Treatment Outcome
8.
Int J Audiol ; 58(1): 21-28, 2019 01.
Article in English | MEDLINE | ID: mdl-30382796

ABSTRACT

OBJECTIVE: The study aimed at examining the usefulness of inter-frequency amplitude ratio (IFAR) of ocular vestibular evoked myogenic potential (oVEMP) in identifying Meniere's disease (MD) and differentiating it from benign paroxysmal positional vertigo (BPPV). DESIGN: A case-control design was used with a double blind approach. Phase 1 included 70 healthy individuals and 36 individuals each with MD and BPPV and Phase 2 included 20 individuals each with MD and BPPV. The age range of the participants in both phases was 15-50 years. All participants underwent oVEMP testing using 500 and 1000 Hz tone bursts and IFAR was obtained. RESULTS: The results in phase 1 revealed significantly higher IFARs in Meniere's disease than BPPV and healthy individuals (p < 0.001). An optimum criterion point of IFAR ≥1.11 for diagnosing MD was found which yielded 80% sensitivity and 98% specificity. The results in phase 2 demonstrated 85% correct identification of MD and 95% correct rejection of BPPV as non-MD. CONCLUSIONS: IFAR of oVEMP appears highly sensitive and specific parameter for identifying MD and a clinically valid tool for differentiating MD from BPPV.


Subject(s)
Benign Paroxysmal Positional Vertigo/diagnosis , Meniere Disease/diagnosis , Vestibular Evoked Myogenic Potentials , Vestibular Function Tests/methods , Vestibule, Labyrinth/physiopathology , Acoustic Stimulation , Adolescent , Adult , Audiometry, Pure-Tone , Benign Paroxysmal Positional Vertigo/physiopathology , Case-Control Studies , Diagnosis, Differential , Double-Blind Method , Female , Humans , Male , Meniere Disease/physiopathology , Middle Aged , Predictive Value of Tests , Reproducibility of Results , Young Adult
9.
Brain Stimul ; 11(4): 709-715, 2018.
Article in English | MEDLINE | ID: mdl-29563049

ABSTRACT

BACKGROUND: Galvanic vestibular stimulation delivered as zero-mean current noise (noisy GVS) has been shown to improve static and dynamic postural stability probably by enhancing vestibular information. OBJECTIVE: /Hypothesis: To examine the effect of an imperceptible level of noisy GVS on dynamic locomotion in normal subjects as well as in patients with bilateral vestibulopathy. METHODS: Walking performance of 19 healthy subjects and 12 patients with bilateral vestibulopathy at their preferred speed was examined during application of noisy GVS with an amplitude ranging from 0 to 1000 µA. The gait velocity, stride length and stride time were analyzed. RESULTS: Noisy GVS had significant effects on gait velocity, stride length and stride time in healthy subjects as well as in patients with bilateral vestibulopathy (p < 0.05). The optimal amplitude of noisy GVS improved gait velocity by 10.9 ±â€¯1.2%, stride length by 5.7 ±â€¯1.2% and stride time by 4.6 ±â€¯7% (p < 0.0001) compared to the control session in healthy subjects. The optimal stimulus improved gait velocity by 12.8 ±â€¯1.3%, stride length by 8.3 ±â€¯1.1% and stride time by 3.7 ±â€¯7% (p < 0.0001) in patients with bilateral vestibulopathy. The improved values of these parameters of locomotion by noisy GVS in the patients were not significantly different from those in healthy subjects in the control condition (p > 0.4). CONCLUSION: Noisy GVS is effective in improving gait performance in healthy subjects as well as in patients with bilateral vestibulopathy.


Subject(s)
Bilateral Vestibulopathy/therapy , Electric Stimulation Therapy/methods , Walking Speed , Adult , Bilateral Vestibulopathy/physiopathology , Case-Control Studies , Electric Stimulation Therapy/adverse effects , Female , Humans , Male , Postural Balance , Signal-To-Noise Ratio , Vestibule, Labyrinth/physiopathology
10.
Audiol Neurootol ; 23(6): 335-344, 2018.
Article in English | MEDLINE | ID: mdl-30677753

ABSTRACT

BACKGROUND: The cervical vestibular evoked myogenic potential (cVEMP) test measures saccular and inferior vestibular nerve function. The cVEMP can be elicited with different frequency stimuli and interpreted using a variety of metrics. Patients with superior semicircular canal dehiscence (SCD) syndrome generally have lower cVEMP thresholds and larger amplitudes, although there is overlap with healthy subjects. The aim of this study was to evaluate which metric and frequency best differentiate healthy ears from SCD ears using cVEMP. METHODS: Twenty-one patients with SCD and 23 age-matched controls were prospectively included and underwent cVEMP testing at 500, 750, 1,000 and 2,000 Hz. Sound level functions were obtained at all frequencies to acquire threshold and to calculate normalized peak-to-peak amplitude (VEMPn) and VEMP inhibition depth (VEMPid). Third window indicator (TWI) metrics were calculated by subtracting the 250-Hz air-bone gap from the ipsilateral cVEMP threshold at each frequency. Ears of SCD patients were divided into three groups based on CT imaging: dehiscent, thin or unaffected. The ears of healthy age-matched control subjects constituted a fourth group. RESULTS: Comparing metrics at all frequencies revealed that 2,000-Hz stimuli were most effective in differentiating SCD from normal ears. ROC analysis indicated that for both 2,000-Hz cVEMP threshold and for 2,000-Hz TWI, 100% specificity could be achieved with a sensitivity of 92.0%. With 2,000-Hz VEMPn and VEMPid at the highest sound level, 100% specificity could be achieved with a sensitivity of 96.0%. CONCLUSION: The best diagnostic accuracy of cVEMP in SCD patients can be achieved with 2,000-Hz tone burst stimuli, regardless of which metric is used.


Subject(s)
Acoustic Stimulation/methods , Labyrinth Diseases/diagnosis , Semicircular Canals/physiopathology , Vestibular Evoked Myogenic Potentials/physiology , Vestibule, Labyrinth/physiopathology , Adult , Aged , Audiometry, Pure-Tone , Female , Humans , Labyrinth Diseases/physiopathology , Male , Middle Aged , Neural Inhibition/physiology , Prospective Studies , Reference Values , Saccule and Utricle/physiopathology , Sound Spectrography , Vestibular Nerve/physiopathology
11.
Clin Neurophysiol ; 128(8): 1513-1518, 2017 08.
Article in English | MEDLINE | ID: mdl-28667933

ABSTRACT

OBJECTIVE: To analyze and summarize the effect of bilateral large vestibular aqueducts in peripheral vestibular organ function. METHODS: Eighteen patients with bilateral large vestibular aqueduct syndrome (LVAS; Study Group) and 18 healthy volunteers (Control Group) were investigated using audiometry, caloric test, sensory organization test (SOT), and vestibular-evoked myogenic potential (VEMP) tests. RESULTS: All 18 patients (36 ears) exhibited sensorineural hearing loss. For cervical VEMP (cVEMP), the Study Group showed lower thresholds (Study Group vs. CONTROL GROUP: 71.4vs. 75.3dBnHL; p=0.006), N1 latencies (24.1vs. 25.2ms; p=0.026) and shorter P1 (15.3vs. 16.6ms; p=0.003), and higher amplitudes (400.7vs. 247.2µV; p<0.001) than the Control Group. For ocular VEMP (oVEMP), the Study Group had lower thresholds (79.3vs. 81.8dBnHL; p=0.046) and higher amplitudes (40.6vs. 14.4µV; p<0.001) than the Control Group. Fourteen of 16 patients (87.5%) who completed caloric tests had abnormal results, and 10 of 18 patients (55.6%) exhibited abnormal results in SOTs. CONCLUSIONS: The hyperfunction of vestibular test in otolithic organs and the hypofunction of vestibular test in semicircular canals, as well as the dysfunction in the balance test were demonstrated in patients with LVAS. SIGNIFICANCE: Our findings can help clinicians gain a better understanding of the characteristics of vestibular organ function in patients with LVAS, which can facilitate optimal targeted treatment.


Subject(s)
Vestibular Aqueduct/diagnostic imaging , Vestibular Aqueduct/physiopathology , Vestibular Diseases/diagnostic imaging , Vestibular Diseases/physiopathology , Vestibular Evoked Myogenic Potentials/physiology , Vestibular Function Tests/methods , Acoustic Stimulation/methods , Adolescent , Adult , Child , Electromyography/methods , Female , Hearing Loss, Sensorineural/diagnostic imaging , Hearing Loss, Sensorineural/physiopathology , Humans , Male , Retrospective Studies , Vestibular Function Tests/standards , Vestibule, Labyrinth/diagnostic imaging , Vestibule, Labyrinth/physiopathology , Young Adult
12.
J Laryngol Otol ; 131(4): 334-340, 2017 Apr.
Article in English | MEDLINE | ID: mdl-28244847

ABSTRACT

OBJECTIVE: This study aimed to evaluate the presence of the N3 potential (acoustically evoked short latency negative response) in profound sensorineural hearing loss, its association with the cervical vestibular evoked myogenic potential and the relationship between both potentials and loss of auditory function. METHODS: Otological examinations of 66 ears from 50 patients aged from 4 to 36 years were performed, and the vestibular evoked myogenic potential and auditory brainstem response were measured. RESULTS: The N3 potential was recorded in 36 out of 66 ears (55 per cent) and a vestibular evoked myogenic potential was recorded in 34 (52 per cent). The N3 potential was recorded in 23 out of 34 ears (68 per cent) with a vestibular evoked myogenic potential response and absent in 19 out of 32 ears (59 per cent) without a vestibular evoked myogenic potential response. The presence of an N3 potential was significantly associated with a vestibular evoked myogenic potential response (p = 0.028), but there was no significant difference in the latency or amplitude of the N3 potential in either the presence or absence of a vestibular evoked myogenic potential. CONCLUSION: The presence of an N3 potential in profound sensorineural hearing loss with good or poor vestibular function can be explained by the contribution of the efferent cochlear pathway through olivocochlear fibres that join the inferior vestibular nerve. This theory is supported by its early latency and reversed polarity, which is masked in normal hearing by auditory brainstem response waves.


Subject(s)
Cochlea/innervation , Evoked Potentials/physiology , Hearing Loss, Sensorineural/physiopathology , Vestibular Evoked Myogenic Potentials/physiology , Vestibular Nerve/physiopathology , Acoustic Stimulation , Adolescent , Adult , Audiometry, Evoked Response , Child , Child, Preschool , Cochlea/physiopathology , Cross-Sectional Studies , Efferent Pathways/physiology , Female , Humans , Male , Reaction Time , Vestibular Function Tests , Vestibule, Labyrinth/physiopathology , Young Adult
13.
Eur Arch Otorhinolaryngol ; 274(1): 85-93, 2017 Jan.
Article in English | MEDLINE | ID: mdl-27422626

ABSTRACT

To determine whether vestibular evoked myogenic potential (VEMP) measurements that combine the VEMP 500/1000 Hz frequency tuning ratio and the inter-aural asymmetry ratio can reliably detect unilateral Meniere's disease ears as compared to healthy controls. Forty-two consecutive patients with certain unilateral Meniere's disease (as confirmed using a locally enhanced inner ear MRI (LEIM)) were assessed. Cervical vestibular evoked myogenic potentials (cVEMP) and ocular vestibular evoked myogenic potentials (oVEMP) were recorded at 500 and 1000 Hz. The VEMP amplitudes, asymmetry ratios, and the 500/1000 Hz amplitude ratios were compared with those of 21 age-matched healthy controls. A multi-frequency VEMPs score that combined: (1) the cVEMP 500/1000 Hz amplitude ratio, (2) the oVEMP 500/1000 Hz amplitude ratio, (3) the 500 Hz cVEMP asymmetry ratio, (4) the 1000 Hz cVEMP asymmetry ratio, produced a ROC curve with an area under the curve (AUC) of 0.814. The inclusion of audiology data further improved the result to 0.906. This score can be used to discriminate with a good degree of clinical accuracy between Meniere's ears (unilateral) and those of healthy controls. Multi-frequency VEMP analysis offers a simple, cost-effective solution to the diagnostic difficulties presented by Meniere's disease.


Subject(s)
Meniere Disease/diagnosis , Vestibular Evoked Myogenic Potentials/physiology , Vestibule, Labyrinth/physiopathology , Acoustic Stimulation , Adult , Aged , Female , Humans , Magnetic Resonance Imaging , Male , Meniere Disease/physiopathology , Middle Aged , ROC Curve , Vestibule, Labyrinth/diagnostic imaging
14.
Laryngoscope ; 127(2): E75-E81, 2017 02.
Article in English | MEDLINE | ID: mdl-27291637

ABSTRACT

OBJECTIVES/HYPOTHESIS: To determine if vestibular potentials could be elicited with electrical stimulation from cochlear implants. STUDY DESIGN: Prospective cohort study. METHODS: Vestibular responsiveness to electrical stimulation from cochlear implants was assessed via vestibular evoked myogenic potential (VEMP) testing in 53 pediatric and young adult patients. RESULTS: Thirty-one participants (58%) showed at least one vestibular potential in response to acoustic stimulation; 33 (62%) had an electrically evoked vestibular response. A cervical VEMP (cVEMP) was present in 45 of the 96 tested ears (47%) in response to acoustic stimulation, and in 34 ears (35%) with electrical stimulation. An ocular VEMP (oVEMP) was elicited acoustically in 25 ears (26%) and electrically in 34 (35%) ears. In the ears with absent responses to acoustic stimuli, electrically evoked cVEMPs and oVEMPs were present in 14 (27%) and 18 (25%) ears, respectively. Electric VEMPs demonstrated shorter latencies than acoustic VEMPs (P < .01). Whereas an increased prevalence of VEMPs was seen at high stimulation levels (P < .01), there was no difference between prevalence proportions with basal (electrode 3) or apical (electrode 20) stimulation (P > .05). CONCLUSIONS: VEMPs can be elicited with electrical stimulation in a proportion of children with cochlear implants, demonstrating current spread from the cochlea to the vestibular system. The presence of electric VEMPs in acoustically nonresponsive ears, along with the shorter latencies of electrically driven VEMPs, suggests that electrical current can bypass the otoliths and directly stimulate vestibular neural elements. LEVEL OF EVIDENCE: 4. Laryngoscope, 2016 127:E75-E81, 2017.


Subject(s)
Acoustic Stimulation , Cochlear Implants , Electric Stimulation , Vestibular Evoked Myogenic Potentials/physiology , Adolescent , Adult , Child , Cohort Studies , Electromyography , Humans , Prospective Studies , Signal Processing, Computer-Assisted , Vestibule, Labyrinth/physiopathology , Young Adult
15.
Hear Res ; 335: 18-24, 2016 05.
Article in English | MEDLINE | ID: mdl-26873525

ABSTRACT

Single-sided deafness patients are now being considered candidates to receive a cochlear implant. With this, many people who have undergone a unilateral vestibular labyrinthectomy for the treatment of chronic vertigo are now being considered for cochlear implantation. There is still some concern regarding the potential efficacy of cochlear implants in these patients, where factors such as cochlear fibrosis or nerve degeneration following unilateral vestibular labyrinthectomy may preclude their use. Here, we have performed a unilateral vestibular labyrinthectomy in normally hearing guinea pigs, and allowed them to recover for either 6 weeks, or 10 months, before assessing morphological and functional changes related to cochlear implantation. Light sheet fluorescence microscopy was used to assess gross morphology throughout the entire ear. Whole nerve responses to acoustic, vibrational, or electrical stimuli were used as functional measures. Mild cellular infiltration was observed at 6 weeks, and to a lesser extent at 10 months after labyrinthectomy. Following labyrinthectomy, cochlear sensitivity to high-frequency acoustic tone-bursts was reduced by 16 ± 4 dB, vestibular sensitivity was almost entirely abolished, and electrical sensitivity was only mildly reduced. These results support recent clinical findings that patients who have received a vestibular labyrinthectomy may still benefit from a cochlear implant.


Subject(s)
Acoustic Stimulation , Cochlear Implants , Cochlear Nerve/pathology , Electric Stimulation , Vestibule, Labyrinth/surgery , Acoustics , Animals , Cochlea/physiopathology , Cochlear Implantation , Cochlear Nerve/physiopathology , Female , Guinea Pigs , Hearing , Hearing Loss, Sensorineural/physiopathology , Humans , Male , Microscopy, Fluorescence , Vestibule, Labyrinth/physiopathology
16.
Eur Arch Otorhinolaryngol ; 273(10): 2953-7, 2016 Oct.
Article in English | MEDLINE | ID: mdl-26742904

ABSTRACT

Ankylosing spondylitis (AS) is a chronic systemic inflammatory disease with unknown etiology. Although sacroiliac joint involvement is the classic sign along with the formed immune mediators, it may result in immune-mediated inner ear disease and may cause damage to the audiovestibular system. Vestibular evoked myogenic potentials (VEMP) is a clinical reflex test used in the diagnosis of vestibular diseases and is performed by recording and evaluating the muscle potentials resulting from the stimulation of the vestibular system with different stimuli. The aim of this study is to evaluate the cervical VEMP test results in AS patients without vestibular symptoms. Thirty-three patients with AS and a control group of 30 healthy volunteers with similar demographic characteristics were evaluated in the study. VEMP wave latency, P13-N23 wave amplitude, and VEMP asymmetry ratio (VAR) values were compared between the groups. The relationship between clinical and laboratory findings of the AS patients and VEMP data were also investigated. Compared with healthy people, this study shows the response rate of patients with ankylosing spondylitis was reduced in the VEMP test, and P13-N23 wave amplitude showed a decrease in AS patients who had VEMP response (p < 0.001). There was no correlation between the clinical and laboratory findings and VEMP findings in patients with ankylosing spondylitis. The data obtained from this study suggest that AS may lead to decreased sensitivity of the vestibular system.


Subject(s)
Labyrinth Diseases/etiology , Spondylitis, Ankylosing/physiopathology , Vestibular Evoked Myogenic Potentials/physiology , Vestibule, Labyrinth/physiopathology , Acoustic Stimulation/methods , Adult , Cross-Sectional Studies , Female , Humans , Labyrinth Diseases/diagnosis , Labyrinth Diseases/physiopathology , Male , Middle Aged , Spondylitis, Ankylosing/complications , Spondylitis, Ankylosing/diagnosis , Young Adult
18.
Neurology ; 86(2): 134-40, 2016 Jan 12.
Article in English | MEDLINE | ID: mdl-26659130

ABSTRACT

OBJECTIVE: To determine whether there are distinct thalamic regions statistically associated with either contraversive or ipsiversive disturbance of verticality perception measured by subjective visual vertical (SVV). METHODS: We used modern statistical lesion behavior mapping on a sample of 37 stroke patients with isolated thalamic lesions to clarify which thalamic regions are involved in graviceptive otolith processing and whether there are distinct regions associated with contraversive or ipsiversive SVV deviation. RESULTS: We found 2 distinct systems of graviceptive processing within the thalamus. Contraversive tilt of SVV was associated with lesions to the nuclei dorsomedialis, intralamellaris, centrales thalami, posterior thalami, ventrooralis internus, ventrointermedii, ventrocaudales and superior parts of the nuclei parafascicularis thalami. The regions associated with ipsiversive tilt of SVV were located in more inferior regions, involving structures such as the nuclei endymalis thalami, inferior parts of the nuclei parafascicularis thalami, and also small parts of the junction zone of the nuclei ruber tegmenti and brachium conjunctivum. CONCLUSIONS: Our data indicate that there are 2 anatomically distinct graviceptive signal processing mechanisms within the vestibular network in humans that lead, when damaged, to a vestibular tone imbalance either to the contraversive or to the ipsiversive side.


Subject(s)
Brain Mapping , Functional Laterality/physiology , Nerve Net/physiopathology , Space Perception/physiology , Thalamus/physiopathology , Vestibule, Labyrinth/physiopathology , Adult , Aged , Female , Humans , Male , Middle Aged , Stroke/diagnosis , Stroke/physiopathology
19.
J Neurol Sci ; 359(1-2): 197-201, 2015 Dec 15.
Article in English | MEDLINE | ID: mdl-26671112

ABSTRACT

OBJECTIVE: To investigate the correlation of the vestibular evoked myogenic potential (VEMP) score with Timed 25-Foot Walk (T25FW), 9-Hole Peg Test (9HPT), Paced Auditory Serial Addition Test (PASAT) and EDSS in patients with multiple sclerosis (MS). METHODS: This prospective, cross sectional study included 52 patients with clinically isolated syndrome (CIS). Cervical VEMP (cVEMP) and ocular VEMP (oVEMP), analyzed in the form of the cVEMP, oVEMP and VEMP scores, T25FW, 9HPT, PASAT and Expanded Disability Status Scale (EDSS) were performed. RESULTS: The only predictor of walking impairment in this study was general disability as measured by the EDSS, after controlling for age, gender, PASAT and EDSS the effect of VEMP score was non-significant (p=0.419). 9HPT of the dominant hand did not correlate with the oVEMP score (rs=0.258, p=0.065), however after controlling for age, gender, PASAT and EDSS, the effect of the oVEMP score on 9HPT of the dominant hand was statistically significant (p=0.017). After controlling for age, gender and oVEMP score, the effect of the PASAT on 9HPT variable for the non-dominant hand was statistically significant (p=0.001). CONCLUSION: We found possible effects of brainstem dysfunction on walking impairment, however they were not seen after correction for EDSS and cognitive dysfunction. On the other hand, dominant hand function seems to be influenced by upper brainstem dysfunction measured with oVEMP, while cognitive dysfunction is related to non-dominant hand function.


Subject(s)
Gait Disorders, Neurologic/etiology , Multiple Sclerosis/complications , Upper Extremity/physiopathology , Vestibular Evoked Myogenic Potentials/physiology , Walking/physiology , Acoustic Stimulation , Adult , Cross-Sectional Studies , Electroencephalography , Female , Humans , Male , Prospective Studies , Severity of Illness Index , Statistics as Topic , Vestibule, Labyrinth/physiopathology , Young Adult
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