Evaluation of ocular and cervical vestibular evoked myogenic potentials in a conductive hearing loss model

Objective:To investigate the effects of conductive hearing loss (CHL) on vestibular evoked myogenic potentials (VEMPs) using a simulated CHL model, and to provide the basis for future studies. Methods:Twenty-one healthy subjects were recruited in this study. We measured ocular VEMPs (oVEMPs) and cervical VEMPs (cVEMPs) in these subjects by air-conduction sound (ACS) stimulation. CHL was simulated later by blocking the right external auditory canal with a soundproof earplug to evaluate its impacts on VEMPs. Subjects' responses before simulated CHL served as the control, and were compared to their responses following simulated CHL. Results: oVEMPs following simulated CHL showed decreased response rate, elevated thresholds, attenuated amplitudes and prolonged N1 latencies compared with those before simulated CHL, and the differences were statistically significant. Similarly, cVEMPs following simulated CHL also showed decreased response rate, elevated thresholds and attenuated amplitudes, with prolonged P1 latencies compared with those before simulated CHL, although only differences in response rate, threshold and amplitude were significant. Conclusions:Conductive hearing loss affects the response rate and other response parameters in oVEMPs and cVEMPs.

Vestibular function for children with insulin dependent diabetes using cervical vestibular evoked myogenic potentials testing

BACKGROUND Healthy vestibular system adjusts balance during static and dynamic conditions.This is important for normal development(standing up and walking).Vestipulopathies(central and peripheral)are common complications of diabetes in adult population.Related studies are scare in children with type 1 diabetes(T1D).AIM To assess saccular function of otolith organ in children with T1D and predictors for its dysfunction.METHODS Cervical vestibular evoked myogenic potential(cVEMP)was used for objective evaluation.RESULTS The study included 40 patients(boys=15;girls=25).Patients had mean age of 13.63±1.50 years,duration of diabetes of 5.62±2.80 years,frequent attacks of diabetic ketoacidosis(55%)and hypoglycemia(30%),hyperlipidemia(20%),hypertension(12.5%)and peripheral neuropathy(40%).Dizziness was found in 10%.Compared to healthy children(n=25),patients had prolonged cVEMP P1 and N1 latencies and reduced P1-N1 amplitude.Bilateral cVEMP abnormalities were found in 60%(vs 25%for unilateral abnormalities).Higher frequencies and severe vestibulopathies were found with chronic diabetes of>5 years,hemoglobin A1c values>7%,frequent diabetic ketoacidosis and hypoglycemic attacks and presence of dizziness.Regression analyses showed that predictors for prolonged P1 latencies and reduced P1-N1 amplitudes were only chronic diabetes(>5 years){odds ratio(OR)=2.80[95%confidence interval(CI):1.80–5.33],P=0.01;OR=3.42(95%CI:2.82–6.81)}and its severity(hemoglobin A1c>7%)[OR=3.05(95%CI:2.55–6.82),P=0.01;OR=4.20(95%CI:3.55–8.50),P=0.001].CONCLUSION Dysfunction or injury of the saccular macula and its pathways is prevalent in children with T1D.Optimum glycemic control is important to prevent diabetes related vestipulopathies.

Clinical characteristics and analysis of vestibular-evoked myogenic potentials in patients with sudden sensorineural hearing loss in different ages

BACKGROUND Numerous studies have found that patients experiencing sudden sensorineural hearing loss(SSHL),with or without accompanying vertigo,often show impaired vestibular function.However,there is a dearth of studies analyzing vestibularevoked myogenic potentials(VEMPs)in SSHL patients across various age groups.AIM To investigate vestibular condition in SSHL patients across various age demographics.METHODS Clinical data of 84 SSHL patients were investigated retrospectively.Audiometry,cervical vestibular evoked myogenic potentials(c-VEMPs),and ocular vestibular evoked myogenic potentials(o-VEMPs)were conducted on these patients.Parameters assessed included the latencies of P1 and N1 waves,as well as the amplitudes of P1–N1 waves.Moreover,the study evaluated the influence of factors such as sex,affected side,configuration of hearing loss,and presence of accompanying vertigo.RESULTS Among the 84 SSHL patients,no significant differences were observed among the three groups in terms of gender,affected side,and the presence or absence of vertigo.Group II(aged 41–60 years)had the highest number of SSHL cases.The rates of absent o-VEMPs in the affected ears were 20.83%,31.58%,and 22.72%for the three age groups,respectively,with no statistically significant difference among them.The rates of absent c-VEMPs in the affected ears were 8.3%,34.21%,and 18.18%for the three age groups,respectively,with significant differences.In the unaffected ears,there were differences observed in the extraction rates of o-VEMPs in the unaffected ears among the age groups.In the three age groups,no significant differences were noted in the three age groups in the latencies of P1 and N1 waves or in the amplitude of N1–P1 waves for c-VEMPs and o-VEMPs,either on the affected side or on the unaffected side,across the three age groups.CONCLUSION The extraction rate of VEMPs is more valuable than parameters.Regardless of the presence of vertigo,vestibular organs are involved in SSHL.Notably,SSHL patients aged 41–60 appear more susceptible to damage to the inferior vestibular nerve and saccule.