Abnormal cVEMP Research Articles

Changes in Vestibular Symptoms and Function After Cochlear Implantation: Relevant Factors and Correlations With Residual Hearing.

ObjectivesThe aim of this study was to evaluate vestibular function loss after cochlear implantation (CI) and the relationship between vestibular function and hearing changes.MethodsSeventy-five patients with CI were enrolled and divided into those with normal preoperative caloric function (group I) and those with a normal preoperative waveform in cervical vestibular evoked myogenic potential (c-VEMP) testing (group II). The relationship between hearing and changes in the vestibular system was analyzed preoperatively and at 3 and 6 months postoperatively.ResultsIn group I, unilateral weakness on the implanted side was detected in five (7.7%) and eight (12.3%) patients at 3 and 6 months post-CI, respectively. By 3 months post-CI, the total slow-phase velocity (SPV; warm and cold stimulations) was significantly different between the implanted and non-implanted sides (P=0.011), and the shift in total SPV from pre- to post-CI was significantly correlated with the average hearing threshold at 6 months post-CI. In group II, an abnormal c-VEMP was detected on the implanted side in six patients (16.2%) at 3 months post-CI, and in six patients (16.2%) at 6 months post-CI. Significant changes were noticed in the P1 and N1 amplitude at 3 months postCI (P=0.027 and P=0.019, respectively).ConclusionVestibular function and residual hearing function should be afforded equal and simultaneous consideration in terms of preservation.

Evaluation of utricular and saccular function in BPPV patients: The role of VEMP in diagnosis

Aim: The pathological cause of Benign Paroxysmal Positional Vertigo (BPPV) is the degeneration of the otolith organs (utricle and sacculus). Vestibular Evoked Myogenic Potentials (VEMP) assess the functions of the otolith organs. The objective of this research was to evaluate the otolith organ functions of patients with unilateral idiopathic BPPV (canalolithiasis of the posterior and lateral semicircular canals) by cVEMP and oVEMP tests. Material and Methods: The study prospectively included 35 patients with BPPV (canalolithiasis of the posterior and lateral semicircular canals) and 30 healthy individuals. Bilateral cVEMP and oVEMP tests were administered to all participants. Participants were divided into three groups: control, BPPV-affected ear, and unaffected ear.Results: In our study, cVEMP and oVEMP abnormalities were statistically significantly different both between the affected and unaffected ear groups and between the affected ear and control groups. There were statistically significant differences in the cVEMP and oVEMP amplitude values both between the affected and unaffected ear groups and between the affected ear and control groups. Also, the asymmetry ratios of the cVEMP and oVEMP tests were statistically significantly different between the case group and the control group. The cVEMP and oVEMP wave latencies (p1, n1, p1-n1) were not statistically significantly different among the BPPV-affected ear, unaffected ear, and control groups. The results of measurements were not statistically significantly different between the posterior and lateral canal involvement subgroups of BPPV patients.Conclusion: Abnormal cVEMP and oVEMP test results, which are observed more frequently in patients with BPPV compared to the control group, indicate utricular and saccular degeneration. Higher oVEMP abnormality ratios compared to those of cVEMP in BPPV patients suggest that utricular dysfunction may be more common than saccular dysfunction.

Towards a new staging of Ménière's disease: a vestibular approach.

SUMMARYMénière’s disease (MD) is characterised by intermittent episodes of vertigo, fluctuating sensorineural hearing loss, tinnitus and aural pressure. Histopathologically, endolymphatic hydrops are seen initially in the cochlear duct and saccule, and with progression of the disease subsequent involvement of the utricle and semicircular canals occurs. The aims of this study are: 1) to assess the function of the saccule, utricle and three semicircular canals using cervical vestibular evoked myogenic potential (cVEMP), ocular VEMP (oVEMP) and video head impulse test (vHIT) in Ménière’s patients, and 2) to correlate the findings with the different stages of MD. Forty patients diagnosed with unilateral definite MD according to the AAO-HNS (1995) criteria were tested. They were divided into four subgroups according to the stage of MD using the average of 500, 1000, 2000 and 3000 Hz pure tone thresholds of the worst documented audiogram during the 6-month interval before examination. A control group of 40 healthy age-matched adults was equally divided into four corresponding subgroups according to their pure tone average. 500 and 1000 Hz tone burst air conduction cVEMP and oVEMP tests, bithermal caloric test and video HIT for all semicircular canals were recorded for both groups. The results of this study showed that the highest prevalence of abnormalities in Ménière’s patients were seen in the PTA (85%), followed by cVEMP (72.5%) and oVEMP (67.5%). Caloric test abnormalities followed with a lower prevalence of 32.5%. The vHIT presented the lowest prevalence of abnormalities with 20% in the lateral canal, 7.5% in the anterior and 5% in the posterior. This pattern of abnormality agrees with the histopathological pattern of hydrops formation in the vestibular system. The findings of the current study suggest that with the advancement in the stage of MD, abnormal cVEMP, oVEMP, caloric and vHIT responses occur following the histopathological evidence of progression of the disease from the saccule up to the semicircular canals. Based on these findings, the authors suggest a new staging scheme for MD.

Clinical value of vestibular-evoked myogenic potential tests in patients with sudden sensorineural hearing loss

BackgroundThis study aims to investigate the clinical value of two kinds of vestibular-evoked myogenic potentials in patients with sudden sensorineural hearing loss (SSNHL).MethodsA total of 82 patients were divided into two groups: vertigo group and non-vertigo group. All patients underwent examinations for pure tone hearing thresholds, middle ear analysis, the videonystagmography, caloric tests, and vestibular-evoked myogenic potentials elicited from the sternocleidomastoid and extraocular muscle. In addition, 30 healthy subjects were selected as the control group.ResultsFor the 30 healthy subjects, the average latency of p13 and n23 of the cervical vestibular evoked myogenic potentials (cVEMPs) were 13.13 ± 2.89 ms and 23.51 ± 3.25 ms, respectively, and the bilateral amplitude asymmetry rate ranged within 0.05–0.31. The average latency of n10 of the ocular vestibular evoked myogenic potentials (oVEMPs) was 10.13 ± 0.48 ms. The average amplitude of the n10-p15-wave was 5.58 ± 0.65 μV. Among the 35 vertigo patients with SSNHL, 27 patients had normal cVEMP and oVEMP examination results, five patients had abnormal oVEMP examination results, and five patients had abnormal cVEMP examination results. The latency and amplifier of oVEMPs and cVEMPs were within the normal range in 47 SSNHL patients without vertigo. The chi-square value was 5.647, the P-value was equal to 0.017, and the difference was statistically significant at a confidence interval of 95%.ConclusionsOVEMPs and cVEMPs can be used evaluate the vestibular nerve function of SSNHL patients with vertigo.

Vestibular testing in children with severe-to-profound hearing loss

Many studies showed that children with sensorineural hearing loss (SNHL) have possible vestibular affection which is related to the severity of cochlear pathology. Objectivesthis work is designed to evaluate vestibular function in children with congenital severe to profound SNHL and correlate the degree of hearing loss with the results of vestibular tests. Methods: this work included 52 children divided into two groups; control group consisted of 20 normal hearing children with no vestibular complaints, and study group consisted of 32 children with congenital severe to profound SNHL. All children were submitted to basic audiologic evaluation, combined vestibular evoked myogenic potentials, sinusoidal harmonic acceleration test (SHA) of rotatory chair test. Resultsall children in the control group had normal oVEMP and cVEMPs results while abnormal cVEMPs and oVEMPs results were found in 89% and 96.9% of the tested ears of the study group respectively. Sinusoidal harmonic acceleration test results were normal in control group with significant reduction in gain, phase lead and higher level of asymmetry in 50% of the children in study group. There was a significant relation between the degree of hearing loss and the cVEMPs, oVEMPs abnormalities, while SHA test results showed no such relationship. ConclusionThere is an evident vestibular abnormalities in children with severe to profound sensorineural hearing loss as revealed by the rotatory chair testing and VEMPs recordings. Vestibular assessment is very important in such group as it has an impact on their rehabilitation plan.

An app-based diary for vestibular disorders: The DizzyQuest

The otolith-collic and otolith-ocular reflexes of patients who experienced episodic tilting or translational sensations in the pitch plane without any other vestibular symptoms were assessed using cervical vestibular evoked myogenic potentials (cVEMP) and ocular vestibular evoked myogenic potentials (oVEMP). Eleven patients (4 men and 7 women, mean age = 40.4) were enrolled. All of the patients complained of episodic tilting or translational sensations in the pitch plane. Patients with a medical history of rotatory vertigo, loss of consciousness, head trauma, or symptoms of central nervous dysfunction or proprioceptive dysfunction and those who had been definitely diagnosed with a disease that causes disequilibrium were excluded. All 11 patients underwent cVEMP and caloric tests. Ten patients participated in the oVEMP tests. Seven of the 11 patients exhibited unilateral cVEMP absences, two displayed bilateral cVEMP absences, one demonstrated unilaterally decreased cVEMP, and one displayed normal cVEMP. Concerning oVEMP, 2 of the 10 patients showed unilateral oVEMP absences, 2 displayed bilateral oVEMP absences, 2 exhibited unilaterally decreased oVEMP, and 4 displayed normal oVEMP. All patients exhibited normal bilateral caloric responses. These findings were distinct from the results obtained for patients who experienced episodic lateral tilting sensations in previous studies. While most of the latter patients exhibited abnormal oVEMP, the patients in the present study tended to display abnormal cVEMP. These results suggest that patients with episodic tilting or translational sensations in the pitch plane suffer from saccular dysfunction. We propose “idiopathic otolithic vertigo” as a clinical entity and suggest that it is caused by idiopathic saccular dysfunction and/or utricular dysfunction.

Otolith dysfunction in recurrent benign paroxysmal positional vertigo after mild traumatic brain injury

Background: The pathogenesis of recurrence of traumatic benign paroxysmal positional vertigo (BPPV) is poorly understood by far.Objectives: To evaluate the value of secondary otolith dysfunction using vestibular evoked myogenic potential (VEMP) test in the pathogenesis of recurrence of BPPV after mild traumatic brain injury (mTBI).Material and methods: We reviewed 42 patients with BPPV after mTBI. According to recurrence, patients were divided into two groups. Both cervical VEMP (cVEMP) and ocular VEMP (oVEMP) tests were performed on all of them.Results: We detected abnormal cVEMP responses in four (26.7%) patients in the recurrent BPPV group after mTBI and five (18.5%) patients in the non-recurrent BPPV group after mTBI, and there was no significant difference between both groups. We detected abnormal oVMEP responses in nine (60.0%) patients in the recurrent BPPV group after mTBI and six (22.2%) patients in the non-recurrent BPPV group after mTBI, and there was a significant difference between both groups.Conclusions and significance: Our study shows that oVEMP abnormalities in recurrent BPPV group after mTBI are significantly higher than those in non-recurrent BPPV group after mTBI. Therefore, we can conclude that secondary utricular dysfunction may be a potential pathogenesis of recurrence of traumatic BPPV.

Cervical vestibular evoked myogenic potential and video head impulse test findings in benign paroxysmal positional vertigo

Background Benign paroxysmal positional vertigo (BPPV) is the most common cause of vertigo. Approximately 20% of all dizziness is due to BPPV. Objective To assess the peripheral vestibular function in a group of patients with BPPV versus group of normal population by using the cervical vestibular evoked myogenic potential (cVEMP) and video head impulse test (vHIT). Materials and methods This is a comparative cross-sectional study. A total of 60 individuals [20 apparently healthy controls (40 ears) and 40 patients with BPPV, who initially were diagnosed by Dix–Hallpike test/supine roll test], were included in the study. All participants gave their written consent before participation in the study. The control as well as the study group was subjected to basic audiological evaluation and vestibular evaluation. Results Regarding the vHIT, there was a statistically significant difference between control and study groups regarding the left vertical canal gain and the asymmetry (P Conclusion Significant abnormal cVEMP in BPPV may indicate saccular involvement in the BPPV pathophysiology, which needs more research to prove or disprove it. Abnormal vHIT gain and asymmetry of the left vertical canal only needs more research in a large sample size.

Lermoyez syndrome revisited: 100-year mystery

Objective: This study revisited seven patients with Lermoyez syndrome over the past 25 years using an inner ear test battery to elucidate its mechanism. Methods: From 1992 to 2017, we have experienced 4096 patients with Meniere’s disease (MD) and seven patients (5 males and 2 females, 8 ears) with Lermoyez syndrome. Two of the Lermoyez patients were elderly, aged 71 and 85 years. An inner ear test battery comprising audiometry, ocular and cervical vestibular-evoked myogenic potential (oVEMP and cVEMP) tests, and caloric test were performed. Results: Significant improvement of mean hearing levels (MHLs) was identified at low and middle frequencies after vertiginous attack, but not at high frequencies. Inner ear deficits in Lermoyez patients ran from abnormal hearing (100%) to abnormal cVEMP (43%), caloric (38%) and oVEMP (0) tests, exhibiting a significantly declining sequence. This declining sequence differed from that in MD. Conclusions: Lermoyez syndrome is extremely rare, with prevalence relative to MD of 0.2%. The mechanism is considered as blockage in the ductus reuniens caused by dislodged saccular otoconia. Aging and trauma are two precipitating factors for the dislodged saccular otoconia, which may explain why Lermoyez syndrome occurs most frequently in males and some elderly.

Comparison of cervical vestibular evoked potentials evoked by air-conducted sound and bone-conducted vibration in vestibular Schwannoma patients

Objective: The vestibular evoked myogenic potential (VEMP) is associated with otolithic afferents and can be used to evaluate the function of the saccule and utricle. In this study, we compared cervical VEMP evoked by stimulation with Air-conducted sound (ACS) and bone-conducted vibration (BCV) to the forehead and investigated whether BCV can be used as a substitute for ACS.Methods: Data were obtained from 33 patients with vestibular schwannoma. Vestibular examinations were performed preoperatively. VEMP was obtained upon stimulation with ACS (ACS cVEMP) and BCV to the forehead using a minishaker (BCV cVEMP). Vestibular function was also analyzed using the caloric test and ocular VEMP (oVEMP) testing. oVEMP was measured using bone-conductive vibration to the forehead. The results of BCV cVEMP, ACS cVEMP, and oVEMP were compared by the caloric test.Results: Rates of patients with abnormal ACS cVEMP, BCV cVEMP, oVEMP, and caloric test results were 78.8%, 75.8%, 78.8%, and 69.7%, respectively. BCV cVEMP did not correlate with ACS cVEMP, but correlated with oVEMP and caloric test results.Conclusion: BCV cVEMP did not correlate with ACS cVEMP. Therefore, BCV cVEMP cannot be used as a substitute for ACS cVEMP.

Pediatric Meniere's disease

ObjectiveThis study adopted an inner ear test battery comprising audiometry, and ocular vestibular evoked myogenic potential (oVEMP), cervical VEMP (cVEMP), and caloric tests to investigate the sequence of inner ear deficits in pediatric Meniere's disease (MD). MethodsFrom 2005 to 2016, a total of 24 MD children aged <15 years old underwent otoscopy, CT scan, blood test, and an inner ear test battery. Nine subjects were males and 15 were females, with mean age of 12 years. Right ear was affected in 3 patients, left ear in 5 patients, and both ears in 16 patients (67%). Eight (33%) of the 24 MD children had positive family history. ResultsInner ear deficits in MD children ran from abnormal hearing (25%) to abnormal cVEMP (20%), oVEMP (13%), and caloric (12%) tests, exhibiting a significantly declining sequence from the cochlea, to the saccule, utricle and semicircular canals. Analysis between the laterality and family history revealed a significantly positive correlation. ConclusionPediatric MD is rare, accounting for 2.3% prevalence in MD patients. The inner ear deficits in pediatric MD showed a significantly declining sequence from the cochlea, to the saccule, utricle and semicircular canals, mimicking the sequence in adult MD. One-third MD children had positive family history, which may explain the high rate of bilateral affliction and symmetrical hearing levels on both ears.

Study of the relationship between cVEMP and ABR 500 Hz

ObjectiveTo evaluate the possible contribution of the saccular projections in generation ABR 500 Hz at high intensity by investigating the relationship between cVEMP and ABR 500 Hz in normal subjects and those with unilateral saccular dysfunction. SubjectsTwenty dizzy adults with unilateral affected cVEMP compared to twenty healthy subjects. MethodsAll subjects were subjected to basic audiological evaluation (pure tone audiometry, speech audiometry and immittancemetry), cVEMP and ABR using 500 Hz tone burst at 90 dB nHL. The dizzy patients within the study group were subjected to VNG to exclude another vestibular affection. The resultsWe found that patient’s abnormal cVEMPs response mostly had prolonged ABR 500 Hz wave V latency, whereas unaffected ears presented with normal findings. ConclusionUsing ABR 500 Hz in the battery approach tests of vestibular assessment can produce valuable data for judgment on the site of a lesion.

Abnormal Cervical Vestibular-Evoked Myogenic Potentials Predict Evolution of Isolated Recurrent Vertigo into Meniere's Disease.

Vestibular-evoked myogenic potentials (VEMPs) can be abnormal in patients with idiopathic recurrent spontaneous vertigo. We aimed to determine whether abnormal cervical vestibular-evoked myogenic potentials (cVEMPs) can predict evolution of isolated recurrent vertigo into Meniere's disease (MD). We had followed up 146 patients with isolated recurrent vertigo and an evaluation of cVEMPs for 0-142 months [median = 6, interquartile range (IQR) = 0-29] at the Dizziness Clinic of Seoul National University Bundang Hospital from June 2003 to May 2014. We defined the variables associated with a progression into MD and calculated cumulative progression rates. Among the 94 patients with recurrent vertigo and abnormal cVEMPs, 18 (18/94, 19%) showed an evolution into MD while only 2 of the 50 (4%) patients with normal cVEMPs evolved into MD during the follow-up (p = 0.01). The interval between onset of vertigo and development of cochlear symptoms ranged from 1 month to 13.6 years (median = 3 years, IQR = 0.5-4.5 years). Overall, pure tone audiometry (PTA) threshold at 0.25 kHz [hazard ratio (HR) = 1.1, 95% confidence interval (CI) = 1.0-1.2] and abnormalities of cVEMPs (HR = 5.6, 95% CI = 1.3-25.5) were found to be significantly associated with a later conversion into MD. The cumulative progression rate was 12% (95% CI = 5-18) at 1 year, 18% (8-26) at 2 years, and 22% (11-32) at 3 years. Abnormal cVEMPs may be an indicator for evolution of isolated recurrent vertigo into MD. Patients with isolated recurrent vertigo may be better managed conforming to MD when cVEMPs are abnormal.

Effects of Peripheral Vestibular Dysfunction on Dynamic Postural Stability Measured by the Functional Reach Test and Timed Up and Go Test.

To investigate the influence of vestibular function on dynamic postural stability assessed by the functional reach test (FRT) and the timed up and go test (TUG). Retrospective study. Tertiary referral center. The FRT and TUG were performed in 399 patients with dizziness. The effects of peripheral vestibular dysfunction assessed by the caloric test and cervical vestibular evoked myogenic potentials (cVEMPs) to air-conducted sound (500 Hz, tone burst) on the results of FRT and TUG were analyzed. Neither FRT nor TUG scores showed significant differences in relation to the results of the caloric test ( P > .3). The FRT scores in patients who showed abnormal cVEMP responses on both sides were significantly smaller than those in patients who showed normal cVEMP responses ( P < .01). The TUG scores in patients who showed abnormal cVEMP responses on both sides were significantly greater than those in patients who showed normal cVEMP responses ( P < .05). The vestibulo-spinal reflex mediated by the saccule and its afferents is one of the factors that influence the maintenance of dynamic postural stability as measured by FRT and TUG.

Otolith Dysfunction in Persons With Both Diabetes and Benign Paroxysmal Positional Vertigo.

Vestibular dysfunction is a well-recognized complication of type 2 diabetes (DM) that may contribute to increased fall risk. The prevalence of benign paroxysmal positional vertigo (BPPV) is higher in people with DM. The impact of DM on the otolith organs of the vestibular system in people with BPPV is unknown. The purpose of this study was to analyze otolith function using vestibular-evoked myogenic potential (VEMP) tests in people with DM and concurrent BPPV (BPPV + DM), and to examine the relationships between VEMP variables and diabetes-related variables. Prospective, cross-sectional study. Tertiary academic medical center. Participants 40 to 65 years were recruited in four groups: controls (n = 20), people with DM (n = 19), BPPV (n = 18), and BPPV + DM (n = 14). Saccule and utricle function were examined using cervical VEMP (cVEMP) and ocular VEMP (oVEMP), respectively. Diabetes-related variables such as HbA1c, duration of diabetes, and presence of sensory impairment due to diabetes were collected. The frequency of abnormal cVEMP responses was higher in the DM (p = 0.005), BPPV (p = 0.003), and BPPV + DM (p <0.001) groups compared with controls. In the participants with diabetes, higher HbA1c levels were correlated with prolonged P1 (p = 0.03) and N1 latencies (p = 0.03). The frequency of abnormal oVEMP responses was not different between groups (p = 0.2). Although BPPV and DM may independently affect utricle and saccule function, they do not seem to have a distinct cumulative effect.

Saccular Dysfunction in Low-Frequency Age-Related Sensorineural Hearing Loss

Objective: To estimate the relationship between saccular dysfunction and low frequency age-related sensorineural hearing loss (a-SNHL). Methods: In this case-control study, sixty old men volunteers evaluated met inclusion criteria. They presented to the audiology department of Hamadan University of medical sciences (Hamadan, Iran). After history taking, all of audiological tests done on same. Results: The comparison of the mean latencies and the mean peak-to-peak amplitudes of the cVEMPs in two groups had significant differences (P &lt; 0.05). The control group with mild high tone hearing loss (normal pure tone thresholds in low to mid frequencies) had normal cVEMPs findings. The case subjects with flat audiogram had abnormal cVEMPs results. Conclusion: Sound sensitivity of the saccule tended to decline when a-SNHL in low frequencies increased. The weakening in cochlear and saccular function of aging may reveal the mechanical failure of both structures, which include the insufficiency of physical properties of the cochlea and the otolithic organ.

The influence of vestibular evoked myogenic potential and vestibular caloric test on the prognosis of sudden deafness

Objective: To explore the effect of vestibular evoked myogenic potential and vestibular caloric test on the prognosis of sudden deafness. Method:One hundred and seven patients with sudden deafness were enrolled in this study, the vestibular evoked myogenic potential(cVEMP ) and vestibular caloric test were evaluated(113 ears). Based upon the results of the tests, patients were divided into cVEMP normal and abnormal groups, vestibular caloric test normal and abnormal groups. The treatment effects were then compared between groups.Result: In seventytwo ears with normal cVEMP, the treatment of 42 ears is effective(58.33%); in fortyone ears with abnormal cVEMP the treatment of 12 ears is effective(29.27%); the difference in the treatment efficiency was significant between the two groups. In sixtyseven ears with normal caloric test, the treatment of 40 ears was effective(59.70%); and in fortysix ears with abnormal caloric test, the treatment of 14 ears is effective(30.43%); the difference in the treatment efficiency between the two groups was significant. Additionally, the treatment of 21 ears with both abnormal cVEMP and caloric test showed ineffective, while the treatment of 28 ears with normal cVEMP and caloric test was effective, which showed significant differences. Conclusion:The prognosis of sudden deafness in patients with normal cVEMP and caloric test is better than the patients with abnormal cVEMP and caloric test, indicating that the results of cVEMP and caloric test can be used to help determine the prognosis of sudden deafness in clinical treatment.

Secondary Endolymphatic Hydrops After Acoustic Trauma.

This study applied an inner ear test battery in patients with secondary hydrops after acoustic trauma to assess the inner ear deficits. Retrospective study. University hospital. Twenty patients with secondary hydrops after acoustic trauma were assigned to Group A. The interval between noise exposure and the testing time varied from 1 month to 3 years (median 3 months). Another 20 patients without progressive hearing loss for at least 3 years after acoustic trauma were assigned to Group B. There were no significant differences between the two groups in terms of age, sex, laterality, and noise source. Before treatment, all patients received audiometry, and caloric, ocular vestibular-evoked myogenic potential (VEMP), and cervical VEMP (cVEMP) tests. Percentages of abnormal mean hearing level (MHL), cVEMP test, oVEMP test, and caloric test were 75%, 75%, 61%, and 43% in Group A, and 35%, 57%, 61%, and 39% in Group B, respectively. Both groups exhibited a significantly declining sequence in inner ear function. Comparison of the abnormalities in the inner ear test battery between Groups A and B revealed a significant difference in percentages of abnormal MHL, but not in those of abnormal cVEMP, oVEMP, and caloric tests. Secondary hydrops after acoustic trauma occurs mainly on the cochlear part, but less on the vestibular part probably because previous acoustic trauma, i.e., firearms have severely damaged the vestibular partition.

Vestibular function disorders and potential mechanisms in irradiation nasopharyngeal carcinoma patients

Conclusions: Vestibular function disorders were widespread among nasopharyngeal carcinoma (NPC) patients. The radiation doses to the inner ears were associated with the incidence of vestibular function disorders, but the correlations were mild. The inflammatory responses and possible resolution obstacles of inflammation participated in persistent vestibular function disorders after irradiation. Objectives: To investigate the incidence of vestibular function disorders in NPC patients after irradiation and potential mechanisms. Methods: Patients who received radical intensity-modulated radiotherapy for their NPC were recruited. The serum levels of IL-6 and IL-17 were detected by ELISA method. Vestibular evoked myogenic potential (VEMP) tests were used to evaluate vestibular function and correlation analyses were used to analyze the potential mechanisms of vestibular function disorders. Results: Thirty-eight patients were included. The incidences of abnormal ocular VEMP (oVEMP) and cervical VEMP (cVEMP) were 65.79% and 80.26% at the time of completion of radiotherapy, and 61.84% and 71.05% at 3 months after radiotherapy. The mean and maximum radiation doses to the inner ears were both significantly associated with abnormal oVEMP and cVEMP (p < 0.05, all), but the correlations were all mild. The serum levels of IL-6 and IL-17 were both significantly associated with abnormal oVEMP and cVEMP after irradiation (p < 0.05, all).

Band limited chirp stimulation in vestibular evoked myogenic potentials.

Air conducted vestibular evoked myogenic potentials (VEMP) can be elicited by various low frequency and intense sound stimuli, mainly clicks or short tone bursts (STB). Chirp stimuli are increasingly used in diagnostic audiological evaluations as an effective means to obtain acoustically evoked responses in narrowed or extended frequency ranges. We hypothesized in this study that band limited chirp stimulation, which covers the main sensitivity range of sound sensitive otolithic afferents (around 500Hz), might be useful for application in cervical and ocular VEMP to air conduction. For this purpose we designed a chirp stimulus ranging 250-1000Hz (up chirp). The chirp stimulus was delivered with a stimulus intensity of 100dB nHL in normal subjects (n=10) and patients with otolith involvement (vestibular neuritis) (n=6). Amplitudes of the designed chirp ("CW-VEMP-chirp, 250-1000Hz") were compared with amplitudes of VEMPs evoked by click stimuli (0.1ms) and a short tone burst (STB, 1-2-1, 8ms, 500Hz). CVEMPs and oVEMPs were detectable in 9 of 10 normal individuals. Statistical evaluation in healthy patients revealed significantly larger cVEMP and oVEMP amplitudes for CW-VEMP-chirp (250-1000Hz) stimuli. CVEMP amplitudes evoked by CW-VEMP-chirp (250-1000Hz) showed a high stability in comparison with click and STB stimulation. CW-VEMP-chirp (250-1000Hz) showed abnormal cVEMP and oVEMP amplitudes in patients with vestibular neuritis, with the same properties as click and STB stimulated VEMPs. We conclude that the designed CW-VEMP-chirp (250-1000Hz) is an effective stimulus which can be further used in VEMP diagnostic. Since a chirp stimulus can be easily varied in its properties, in particular with regard to frequency, this might be a promising tool for further investigations.