Vestibular evoked myogenic potentials in children

Subjective visual vertical/horizontal and video head impulse test in dyslexic children

Different studies have tried to establish a relationship between dyslexia and the vestibular system function. Subjective Visual Vertical/Horizontal (SVV and SVH) and Video Head Impulse Test (VHIT) are useful for studying the vestibular system and can be easily performed in children. Our aim was to evaluate the vestibular function in dyslexic children by SVV/SVH and VHIT. We enrolled 18 dyslexic children (10M/8F; mean age 10.7 ± 2.3 years; range 7-14 years) and 18 age-matched children with typical development of learning abilities. All children performed VHIT, SVV and SVH. We found normal gain and symmetry of vestibulo-ocular-reflex both in dyslexic and typically developing children. Fifteen out of 18 dyslexic children (83.3%) showed a difference of at least one amongst SVV or SVH. The mean value of SVV was 2.3° and the mean value of SVH was 2.6°. Statistical analysis showed a significant difference between typically developing and dyslexic children for both SVV and SVH. We confirm a relationship between dyslexia and the alteration of SVV and SVH. Our results could be related to the pathogenetic hypothesis of a visual processing impairment related to a dysfunction of the magnocellular pathway or to a general deficit related to a multimodal cortical network.

A Clinical Framework for Video Head Impulse Testing and Vestibular Evoked Myogenic Potential Assessments in Primary School-Aged Children

OBJECTIVES

This study aimed to offer normative data and age trends of an age-appropriate vestibular test protocol in a large group (n = 140) of school-aged children (6 to 13 years old) as well as to provide a practical and clinical framework for accurate performance and interpretation of vestibular test results in this specific age group.

DESIGN

The typically developing participants (mean age of 9.51 ± 2.04 years) were recruited to provide a representative group of 20 children for each of the seven age groups that were composed of children aged from 6 to 13 years in 1-year intervals. Each age group consisted of 10 boys and 10 girls. The protocol comprises the video head impulse test, and cervical and ocular vestibular evoked myogenic potential assessments to provide a child-friendly, noninvasive, short, and portable test battery, which is equally applicable in the hospital and office-practice, and which provides information on the integrity of all five parts of the peripheral vestibular system.

RESULTS

The study demonstrates that all included tests and methods, with an overall test duration of 25 min 12 sec ± 5 min 10 sec, were feasible to perform in primary school-aged children, taking into account some practical adaptations. Concerning the video head impulse test, no clinically relevant sex and age effects were noted. However, t tests revealed significant differences for the mean gain of the horizontal (right > left; t [139] = 14.563; p < 0.001) and posterior semicircular canals (left > right; t [139] = -4.823; p < 0.001) between both sides. For the cVEMP assessment, no laterality differences were observed for any of the parameters, but a significantly shorter N1 latencies in the youngest age categories (<8 years), compared with the oldest groups were observed [ F (6,118) = 8.336; p < 0.001; partial ƞ ² = 0.298]. For all oVEMP parameters, no laterality, sex, or age differences were seen. On the basis of the presented normative data, cutoff criteria were proposed with accompanying clinical recommendations to perform vestibular function testing in this target population.

CONCLUSIONS

This is the first study in a large group of school-aged children offering normative data and age trends of an age-appropriate vestibular test protocol that evaluates the integrity of all parts of the peripheral vestibular organ. The reported normative values and clinical cutoff values will enable appropriate and age-specific interpretation of clinical and scientific results. Moreover, in combination with extensive history taking, and additional vestibular testing (e.g., rotatory chair test, caloric testing) when needed, the results of this study may support clinicians in the diagnosis of side-specific and location-specific vestibular deficits, which is required for accurate counseling and referral for further follow-up and/or intervention.

Validity of Italian adaptation of the Vanderbilt Paediatric Dizziness Handicap Inventory

Objective

The paediatric caregiver version of the Dizziness Handicap Inventory (DHI-PC) questionnaire is a useful Quality of Life (QoL) evaluation instrument for children experiencing dizziness, vertigo or unsteadiness. Its English version has been validated for use with a paediatric population between 5 and 12 years of age. The aim of this work is to validate the DHI-PC into Italian for both patient assessment and appropriate rehabilitative treatment planning.

Materials and methods

Cross-cultural adaptation of the DHI-PC was performed using standard techniques. Items of the original questionnaire were translated into Italian by two bilingual investigators. Two native English speakers carried out a back translation of the new version that was compared with the original to check that they had the same semantic value. A pre-final version was obtained by an expert committee and was applied in a pilot test.

Results

A total of 42 patient caregivers completed the final adapted questionnaire twice with an interval of 2 weeks. Internal consistency was excellent, with Cronbach's alpha = 0.95.

Conclusions

Our study showed evidence that the Italian version of DHI-PC is a valid and reliable tool to quantify the degree of dizziness handicap and its application is recommended.

Establishing cervical vestibular evoked myogenic potential (cVEMP) normative data in Singapore school-aged children

OBJECTIVES

The Cervical Vestibular Evoked Myogenic Potential (cVEMP) is often employed in routine clinical practice as part of the vestibular test battery assessments. However, there is currently no well-established paediatric cVEMP normative data in Singapore. Additionally, limited literature has examined the relationship between neck length and cVEMP parameters. The main aims of this study are to 1) establish cVEMP normative data from Singaporean school-aged children aged 6-12 years old, and 2) examine if there is a significant correlation between neck length and cVEMP parameters.

METHODS

31 healthy children participated in this study. Every participant was screened to ensure that they had normal auditory and vestibular profiles before completing the cVEMP procedure, which involved 500 Hz tone burst through insertphones and head elevation from supine position as the method of neck contraction.

RESULTS

The response rate in 62 ears was 98.4% at 95 dBnHL and 100% at 100 dBnHL. The mean P1 and N1 latencies were 13.96 ± 1.17 m s and 21.50 ± 1.66 m s, with a mean corrected P1-N1 amplitude of 0.88 ± 0.34, and mean asymmetry ratio of 13 ± 10%. Median threshold was 80 dBnHL. Significant positive correlation between neck length and both P1, N1 latencies, and significant negative correlation between neck length and corrected P1-N1 amplitude were observed.

CONCLUSIONS

cVEMP paediatric normative data has been established for Singaporean school-aged children. The study also confirmed that neck length did have a significant influence on both latencies and corrected amplitude.

Pediatric Vestibular Assessment: Clinical Framework

OBJECTIVES

Although vestibular deficits can have severe repercussions on the early motor development in children, vestibular assessment in young children has not yet been routinely integrated in clinical practice and clear diagnostic criteria to detect early vestibular deficits are lacking. In young children, specific adjustments of the test protocol are needed, and normative data are age-dependent as the vestibular pathways mature through childhood. Therefore, this study aims to demonstrate the feasibility of an extensive age-dependent vestibular test battery, to provide pediatric normative data with the concurrent age trends, and to offer a clinical framework for pediatric vestibular testing.

DESIGN

This normative study included 133 healthy children below the age of 4 years (mean: 22 mo, standard deviation: 12.3 mo, range: 5-47 mo) without history of hearing loss or vestibular symptoms. Children were divided into four age categories: 38 children younger than 1 year old, 37 one-year olds, 33 two-year olds, and 25 three-year olds. Children younger than 3 years of age were examined with the video Head Impulse Test (vHIT) of the horizontal semicircular canals, cervical vestibular evoked myogenic potentials (cVEMP) with bone conduction stimuli, and the rotatory test at 0.16, 0.04, and 0.01 Hz. In 3-year old children, the vHIT of the vertical semicircular canals and ocular vestibular evoked myogenic potentials (oVEMP) using a minishaker were added to the protocol.

RESULTS

The horizontal vHIT appeared to be the most feasible test across age categories, except for children younger than 1-year old in which the success rate was the highest for the cVEMP. Success rates of the rotatory test varied the most across age categories. Age trends were found for the vHIT as the mean vestibulo-ocular reflex (VOR) gain increased significantly with age (r = 0.446, p < 0.001). Concerning the cVEMP, a significant increase with age was found for latency P1 (r = 0.420, p < 0.001), rectified interpeak amplitude P1-N1 (r = 0.574, p < 0.001), and averaged electromyographic (EMG) activity (r = 0.430, p < 0.001), whereas age trends for the latency N1 were less pronounced (r = 0.264, p = 0.004). Overall, the response parameters of the rotatory test did not show significant age effects ( p > 0.01), except for the phase at 0.01 Hz (r = 0.578, p < 0.001). Based on the reported success rates and age-dependent normative vestibular data, straightforward cutoff criteria were proposed (vHIT VOR gain < 0.7, cVEMP rectified interpeak amplitude < 1.3, oVEMP interpeak amplitude < 10 µV) with accompanying clinical recommendations to diagnose early vestibular impairment.

CONCLUSIONS

In this large cohort of typically developing children below the age of 4 years, the vHIT and cVEMP were the most feasible vestibular tests. Moreover, the age-dependent normative vestibular data could specify age trends in this group of young children. Finally, based on the current results and clinical experience of more than ten years at the Ghent University Hospital (Belgium), a clinical framework to diagnose early vestibular deficits in young patients is proposed.

Effects of acoustic stimulation intensity on air-conducted vestibular evoked myogenic potential in children

Objective

To investigate the effects of acoustic stimulation intensity on ocular and cervical vestibular evoked myogenic potential (oVEMP and cVEMP) responses elicited by air-conducted sound (ACS) in healthy children.

Methods

Thirteen healthy children aged 4–10 years and 20 healthy adults aged 20-40 years with normal hearing and tympanometry were enrolled in this study. All subjects received oVEMP and cVEMP tests under different acoustic stimulation intensities (131, 126, 121, 116, 111 and 106 dB SPL). Mean n1 latency, p1 latency, interpeak latency, amplitude and response rate were investigated and analyzed.

Results

As the acoustic stimulation intensity decreased, for oVEMP, the response rate of children decreased from 100% (131, 126 and 121 dB SPL) to 57.69% (116 dB SPL), 26.92% (111 dB SPL) and 11.54% (106 dB SPL). The response rate of adults decreased from 100% (131 and 126 dB SPL) to 95% (121 dB SPL), 55% (116 dB SPL), 12.5% (111 dB SPL) and 2.5% (106 dB SPL). There were lower n1 latency, p1 latency and higher amplitude in children when comparing by acoustic stimulation intensities (p < 0.05). Regarding cVEMP, the response rate of children decreased from 100% (131, 126 and 121 dB SPL) to 88.46% (116 dB SPL), 53.85% (111 dB SPL) and 26.92% (106 dB SPL). The response rate of adults decreased from 100% (131 and 126 dB SPL) to 95% (121 dB SPL), 85% (116 dB SPL), 37.5% (111 dB SPL) and 7.5% (106 dB SPL). A statistically significant difference was found in amplitude at different acoustic stimulation intensities in both children and adults (p < 0.05). When stimulated by 131 dB SPL acoustic stimulation, there were lower n1 latency, p1 latency and higher amplitude in children in oVEMP and cVEMP compared with adults (p < 0.05).

Conclusion

The response rate and amplitude of oVEMP and cVEMP in children and adults presented significant differences with a decrease in acoustic stimulation intensity. In this study, using 121 dB SPL for children and 126 dB SPL for adults during VEMP test could be regarded as safer stimulation intensities and thus reduced sound exposure.

Vestibular function in children with cochlear implant: Impact and evaluation

Over the last 30 years, cochlear implant (CI) has been dedicated to improving the rehabilitation of hearing impairments. However, CI has shown potential detrimental effects on vestibular function. For children, due to atypical symptoms and difficulty in cooperating with vestibular function tests, systematic and objective assessments of vestibular function with CI have been conducted sparsely. This review focuses on the impact of vestibular function in children with CI and summarized the evaluation of vestibular function in children. In addition, some recommended strategies are summarized and proposed.

Cervical Vestibular-Evoked Myogenic Potentials and Balance Testing in Children with Down Syndrome

Introduction  Vestibular otolith function plays a major role in balance control. Objective  To investigate the saccular and balance functions of children with Down syndrome (DS). Methods  In total, 15 children with DS aged between 9 and 11 years were included. An age- and gender-matched control group (CG) composed of 15 normal participants was also included. The subjects with DS had trisomy 21, without hearing or organic problems, and they had independence in stance. The saccular function among the children with DS and among the controls was tested using air-conduction cervical vestibular-evoked myogenic potentials (cVEMPs). In addition, the static and dynamic balance statuses were evaluated using the following assessments; the Pediatric Balance Scale (PBS), the modified Clinical Test of Sensory Interaction on Balance (mCTSIB), the Romberg test, and the Timed Up and Go (TUG) test. Results  In the present study, the results of the saccular function test showed that there was a significant difference between children with and without DS ( p  < 0.05). The DS subjects had significantly earlier N1 latancy and lower amplitude of the cVEMPs (< 70 μV) compared with the control subjects. The static-dynamic balance ability was statistically and significantly different in children with DS compared with the controls ( p  < 0.05). Conclusion  These results revealed that saccular function seems to be affected in DS subjects. The dysfunction in static and dynamic balance abilities of the children with DS may be attributed to vestibular dysfunction as well as low gross motor skills. This knowledge should be taken into account when assessing motor performance in those subjects. Additional larger studies testing other dimensions of the vestibular system in children with DS are needed.

Saccular function evolution related to cochlear implantation in hearing impaired children

Vestibular sensorial input is essential for psychomotor development of the very small children. In consequence, possible vestibular impairment induced by cochlear implantation in deaf children could affect the balance and walking learning process. Some of cochlear implanted children can present congenital vestibular deficit. The anatomical and embryological relation between auditory and vestibular system explains why congenital neurosensorial hearing loss may associate vestibular impairment. The cochlear implant surgery presents a vestibular lesion risk. Bilateral vestibulopathy, as it appears in early childhood, has a poor prognosis for the psychomotor and cognitive development. Even probably rare, bilateral vestibulopathy induced by simultaneous bilateral cochlear implantation can delay the acquisition of motor skills. This pathology can be avoided by an appropriate surgical indication related to the vestibular preoperative status. This study reports the vestibular saccular functional modifications after the cochlear implantation in children. The cervical vestibular evoked myogenic potentials (cVEMPs) were performed in children before and after the cochlear implantation. Since previous studies report different vestibular impairment related to the portelectrode insertion approach, another objective of our study was to assess the saccular postoperative status depending of the insertion by cochleostomy (CO) or through the round window (RW). We performed cVEMPs for 80 patients (135 cochlear implanted ears) before and after cochlear implantation. We have detected preoperative saccular areflexia in 33 (24.4%) ears. In the group of 102 (75.6%) ears with preoperative normal saccular function, 72 (70.6%) ears preserved the cVEMP response after the surgery, while in 30 (29.4%) ears the cVEMP response was lost. Reporting our findings to the portelectrode insertion method, we found normal saccular function in 73.3% of the cochlear implanted ears by RW surgical approach and in 68.42% ears by CO approach. These results suggest that the RW portelectrode insertion is the recommended strategy in order to avoid the saccular vestibular impairment.

cVEMPs and oVEMPs normative data in Malaysian preschool and primary school-aged children

OBJECTIVE

Vestibular assessments in children are essential for the early identification of vestibular and balance dysfunctions. Vestibular evoked myogenic potentials, cervical (cVEMPs) and ocular (oVEMPs) have been reported to be feasible and effective when assessing otolith function in children. The main aim of the study was to obtain normative data for cVEMPs and oVEMPs from preschool and primary school-aged Malaysian children.

METHODS

A group of 33 healthy children, aged from 5 years 9 months-12 years 4 months (mean ± SD = 8.83 ± 1.92 years), was recruited. Their otolith saccular function was assessed using 750 Hz tone burst for cVEMPs (with ER3A insert phone), while their utricular function was assessed using Brüel & Kjaer Mini-shaker Type 4810 (Naerum, Denmark) for oVEMPs.

RESULTS

For cVEMPs, the mean value of P13 latency, N23 latency, P13-N23 interamplitude and asymmetry ratio were 12.62 ± 1.38 ms, 19.85 ± 1.95 ms, 92.47 ± 50.35 μV and 14.03 ± 9.75%, respectively. For oVEMPs, the mean value of N10 latency, P15 latency, N10-P15 interamplitude and asymmetry ratio were 9.23 ± 1.07 ms, 14.41 ± 1.04 ms, 10.32 ± 5.65 μV and 15.84 ± 11.49%, respectively. Two-way ANOVA analysis found that ear laterality and gender had no significant effect on all cVEMPs and oVEMPs parameters. No significant correlation was found between age and all VEMPs parameters.

CONCLUSIONS

The normative data for cVEMPs and oVEMPs obtained in this study can be used as a guide by health professionals to assess saccular and utricular functions among children age from 5 to 12 years of age.

Bone Conduction Vibration Vestibular Evoked Myogenic Potential (VEMP) Testing: Reliability in Children, Adolescents, and Young Adults

OBJECTIVES

Bone conduction vibration (BCV) vestibular evoked myogenic potentials (VEMP) are clinically desirable in children for multiple reasons. However, no accepted standard exists for stimulus type and the reliability of BCV devices has not been investigated in children. The objective of the current study was to determine which BCV VEMP method (B-71, impulse hammer, or Mini-shaker) yields the highest response rates and reliability in a group of adults, adolescents, and children. It was hypothesized that the Mini-shaker would yield the highest response rates and reliability because it provides frequency specificity, higher output levels without distortion, and the most consistent force output as compared to the impulse hammer and B-71.

DESIGN

Participants included 10 child (ages 5 to 10), 11 adolescent (ages 11 to 18), and 11 young adult (ages 23 to 39) normal controls. Cervical VEMP (cVEMP) and ocular VEMP (oVEMP) were measured in response to suprathreshold air-conducted, 500 Hz tone bursts and 3 types of BCV (B-71, impulse hammer, and Mini-shaker) across 2 test sessions to assess reliability.

RESULTS

For cVEMP, response rates were 100% for all methods in all groups with the exception of the adult group in response to the impulse hammer (95%). For oVEMP, response rates varied by group and BCV method. For cVEMP, reliability was highest in adults using the Mini-shaker, in adolescents using the impulse hammer, and in children using the B-71. For oVEMP, reliability was highest in adults using the Mini-shaker, in adolescents using the Mini-shaker or impulse hammer, and in children using the impulse hammer. Age positively correlated with air-conducted oVEMP amplitude, but not cVEMP amplitude or cVEMP corrected amplitude. Age negatively correlated with all BCV VEMP amplitudes with the exception of cVEMP corrected amplitude in response to the Mini-shaker.

CONCLUSIONS

All BCV methods resulted in consistent cVEMP responses (response rates 95 to 100%) with at least moderate reliability (intraclass correlation coefficient ≥ 0.5) for all groups. Similarly, all BCV methods resulted in consistent oVEMP responses (89 to 100%) with at least moderate reliability (intraclass correlation coefficient ≥ 0.5) except for the B-71 in adults.

Effects of Rhinoplasty on Labyrinthine Function

BACKGROUND

Rhinoplasty is a common surgical procedure that is requested and accepted by patients for cosmetic and functional reasons. Osteotomies are performed on nasal bone, maxillary crest, or vomer to fix the deviations of the nasal dorsum or septum. During the percussion of the osteotomes with the surgical mallet, the vibration energy diffuses to the cranium. Auditory and vestibular systems may be affected by these vibrations.

OBJECTIVES

To assess the effects of rhinoplasty, in which osteotomies were performed using a hammer, on the audiovestibular system.

METHODS

Thirty adults who underwent rhinoplasty were included in the study group. Ten age and gender matched adults who had nasal surgery without surgical mallet or osteotome served as the control group. The patients in both groups were assessed using pure tone audiometry, tympanometry, distortion product otoacoustic emission testing, and vestibular-evoked myogenic potential, as well as video head impulse tests (vHIT) before the operation and 1 week after the operation.

RESULTS

On auditory assessment, there was no significant difference between the study and control groups regarding pure tone thresholds at frequencies of 250 Hz to 8 kHz (P > 0.05) as well as otoacoustic emissions. The vestibular assessment performed by using vestibular-evoked myogenic potential and vHIT did not reveal a statistically significant difference between the groups, before surgery or after surgery (P > 0.05).

CONCLUSIONS

Rhinoplasty appears to be a safe operation in terms of audiovestibular functions, and osteotomy, in which a hammer is usually used, does not have an impact on hearing or balance functions of the ear.

LEVEL OF EVIDENCE 2

Cervical Vestibular-Evoked Myogenic Potentials in Sedated Toddlers

Introduction  Cervical vestibular-evoked myogenic potentials (cVEMPs) are difficult to test in toddlers who cannot follow instructions or stay calm.

Objective  Due to the growing need for vestibular testing in very young children as a part of a delayed walking assessment battery, this study aimed to provide a solution to this problem by recording the cVEMPs in toddlers during sedation.

Method  The cVEMPs measures were assessed in 30 toddlers aged 12 to 36 months with normal motor milestones. They were sedated with chloral hydrate. Then, the head was retracted ∼ 30° backward with a pillow under the shoulders, and turned 45° contralateral to the side of stimulation to put the sternocleidomastoid (SCM) muscle in a state of tension.

Results  The P13 and N23 waves of the cVEMPs were recordable in all sedated toddlers. The cVEMPs measures resulted in the following: P13 latency of 17.5 ± 1.41 milliseconds, N23 latency of 25.58 ± 2.02 milliseconds, and peak-to-peak amplitude of 15.39 ± 3.45 µV. One-sample t -test revealed statistically significant longer latencies and smaller amplitude of the toddlers' cVEMPs relative to the normative data for adults.

Conclusions  The difficulty of cVEMPs testing in toddlers can be overcome by sedating them and attaining a position that contracts the SCM muscle. However, the toddlers' recordings revealed delayed latencies and smaller amplitudes than those of adults.

Vestibular pathology in children with enlarged vestibular aqueduct

OBJECTIVES/HYPOTHESIS

To establish the prevalence of abnormal vestibular test findings in children with enlarged vestibular aqueduct (EVA) and determine if these findings correlate with clinical symptoms, radiographic findings (EVA size and laterality), audiometric findings, and genetic testing in these patients.

STUDY DESIGN

Prospective cohort.

METHODS

Patients 3 to 12 years of age with hearing loss and imaging findings consistent with EVA treated at our tertiary care institution were sequentially enrolled from 2009 to 2011. The following six outcome measurements were analyzed: audiometric findings, EVA laterality, temporal bone measurements, genetic testing, vestibular testing (cervical-evoked myogenic potentials, posturography, rotational chair, and calorics), and vestibular symptoms.

RESULTS

Twenty-seven patients with EVA (mean age 9.2 years, 48% female) were enrolled in and completed the study. Vertigo was reported in six patients. Twenty-four of 27 (89%) had at least one abnormal vestibular test result. Midpoint and operculum size correlated with directional preponderance (P = .042 and P = .032, respectively). Also, high-frequency pure tone average (HFPTA) correlated with unilateral weakness (P = .002). Walking at a later age correlated with abnormal posturography results. There was no correlation between EVA laterality and vestibular test findings.

CONCLUSION

We found a high rate of vestibular pathology in children with EVA; however, the prevalence of abnormal vestibular test findings in this patient population was not correlated with vestibular symptoms. Enlarged vestibular aqueduct size, HFPTA, and walking at a later age were correlated with abnormal vestibular test findings. In view of these results, it may be prudent to consider vestibular testing in children with these clinical characteristics.

LEVEL OF EVIDENCE

2b. Laryngoscope, 126:2344-2350, 2016.

Vestibular-evoked myogenic potentials

The vestibular-evoked myogenic potential (VEMP) is a short-latency potential evoked through activation of vestibular receptors using sound or vibration. It is generated by modulated electromyographic signals either from the sternocleidomastoid muscle for the cervical VEMP (cVEMP) or the inferior oblique muscle for the ocular VEMP (oVEMP). These reflexes appear to originate from the otolith organs and thus complement existing methods of vestibular assessment, which are mainly based upon canal function. This review considers the basis, methodology, and current applications of the cVEMP and oVEMP in the assessment and diagnosis of vestibular disorders, both peripheral and central.

Clinical uses of cervical vestibular-evoked myogenic potential testing in pediatric patients

To demonstrate the feasibility and clinical significance of cervical vestibular-evoked myogenic potential (cVEMP) test in pediatric patients.Retrospective review study was conducted in a pediatric tertiary care facility. A total of 278 patients were identified with adequate data, including medical notes, results of cVEMP, and imaging studies.Among the total of 278 pediatric patients, only 3 children were not able to finish the cVEMP test successfully. In about 90% of the cases, the cVEMP test was requested to investigate a patient's hearing loss and/or vestibular complaints. Over 90% of the cVEMP tests were ordered by specialists such as pediatric otolaryngologists or otologists. Obtained cVEMP results provided useful information in clinical diagnosis and management in all cases.It is feasible to conduct cVEMP testing in children, including infants, and cVEMP testing can provide valuable information in the diagnosis and management of hearing loss and vestibular impairment. This simple and noninvasive test should be embraced by pediatric professionals.

International guidelines for the clinical application of cervical vestibular evoked myogenic potentials: an expert consensus report

BACKGROUND

Cervical vestibular evoked myogenic potentials (cVEMPs) are electromyogram responses evoked by high-level acoustic stimuli recorded from the tonically contracting sternocleidomastoid (SCM) muscle, and have been accepted as a measure of saccular and inferior vestibular nerve function. As more laboratories are publishing cVEMP data, there is a wider range of recording methods and interpretation, which may be confusing and limit comparisons across laboratories.

OBJECTIVE

To recommend minimum requirements and guidelines for the recording and interpretation of cVEMPs in the clinic and for diagnostic purposes.

MATERIAL AND METHODS

We have avoided proposing a single methodology, as clinical use of cVEMPs is evolving and questions still exist about its underlying physiology and its measurement. The development of guidelines by a panel of international experts may provide direction for accurate recording and interpretation.

RESULTS

cVEMPs can be evoked using air-conducted (AC) sound or bone conducted (BC) vibration. The technical demands of galvanic stimulation have limited its application. For AC stimulation, the most effective frequencies are between 400 and 800 Hz below safe peak intensity levels (e.g. 140 dB peak SPL). The highpass filter should be between 5 and 30 Hz, the lowpass filter between 1000 and 3000 Hz, and the amplifier gain between 2500 and 5000. The number of sweeps averaged should be between 100 and 250 per run. Raw amplitude correction by the level of background SCM activity narrows the range of normal values. There are few publications in children with consistent results.

CONCLUSION

The present recommendations outline basic terminology and standard methods. Because research is ongoing, new methodologies may be included in future guidelines.

Role of cervical vestibular evoked myogenic potential response in identifying vestibular dysfunction

Objectives:

To analyse cervical vestibular evoked myogenic potential response parameters in normal volunteers and vertiginous patients.

Subjects and methods:

A prospective study of 50 normal subjects and 50 patients with vertigo was conducted at Chiang Mai University Hospital, Thailand. Cervical vestibular evoked myogenic potential responses were measured using air-conducted, 500-Hz, tone-burst stimuli with subjects in a sitting position with their head turned toward the contralateral shoulder.

Results:

The mean ± standard deviation age and male:female ratio in the normal (44.0 ± 9.3 years; 12:38) and vertigo groups (44.7 ± 9.8 years; 17:33) were not significantly different. The prevalence of absent responses in the normal (14 per cent) and vertigo ears (46 per cent) differed significantly (p < 0.0001). Other cervical vestibular evoked myogenic potential parameters (i.e. response threshold, P1 and N1 latency, P1–N1 interlatency and interamplitude, inter-ear difference in P1 threshold, and asymmetry ratio) showed no inter-group differences.

Conclusion:

The absence of a cervical vestibular evoked myogenic potential response is useful in the identification of vestibular dysfunction. However, patients should undergo a comprehensive battery of other vestibular tests to supplement their cervical vestibular evoked myogenic potential response findings.

Vestibular evoked myogenic potentials in children affected by myelomeningocele

PURPOSE

The aim of the present study is to establish if the vestibular evoked myogenic potentials (VEMPs) could be used as a clinical test for the evaluation of vestibular function in children affected by myelomeningocele (MMC).

MATERIALS AND METHODS

Fifteen children, aged between 3 and 17 years, who had been affected by MMC were investigated. Data obtained from these children were compared with normal data from healthy children of the same age. Electromyographic activity of sternocleidomastoid muscle was recorded, while children were laid supine and asked to raise their head off the bed in order to activate their neck flexors bilaterally. The saccular receptors were acoustically stimulated with a logon of 500 Hz at an intensity of 130 dB peSPL presented monaurally through earphones. In each recording, we analyzed latencies and amplitudes of the p13-and n23 waves and the amplitude ratio between the two ears.

RESULTS

VEMPs were detected to be normal in 13 patients. In particular, the mean p13 and mean n23 latencies were 15.7 (±1.4) and 21.7 (±1.1) ms, respectively; the mean amplitude value was 84.7 (±36.6), while the mean amplitude ratio was 17.4 (±12). A comparison of latencies and amplitude ratios between the children and healthy control group did not reveal any significant difference. On the contrary, a comparison of amplitude values between the two groups showed significant differences.

CONCLUSION

In conclusion, vestibulocollic reflex is normal in patients affected by MMC, and VEMPs could represent a valid and noninvasive technique eligible to investigate the vestibular functions in these children.

Vestibular evoked myogenic potentials in children with sensorineural hearing loss

OBJECTIVE OF THE STUDY

To assess the saccular function using the vestibular evoked myogenic potential (VEMP) test in children with severe to profound sensorineural hearing loss.

METHODS

15 children (12 males and 3 females) with severe to profound sensorineural hearing loss in the age range of 4-12 years constituted the study group. 10 children (6 males and 4 females) with normal hearing constituted the control group. All the children were evaluated for saccular function by using the vestibular evoked myogenic potentials (VEMP).

RESULTS

For study group the mean P1 and N1 latencies values were 15.12ms and 23.86ms, respectively. For control group the mean P1 and N1 latencies were 15.39ms and 23.68ms. The comparison of mean P1 and N1 latencies values between study and control groups revealed no significant difference (p>0.05). Furthermore, the mean amplitude values of VEMP responses for study and control groups were 75.78μV and 160.51μV, respectively. The comparison mean amplitude values between study and control groups revealed statistically significant difference (p<0.05). Out of 15 children in the study group 2 children had the absent VEMP response in both the ears.

CONCLUSION

Because the vestibular function plays an important role in gross motor development in children, audiologists and otologist should recognize and understand the vestibular dysfunction in hearing impaired children and be prepared to undertake appropriate evaluations. However, additional research is needed on a larger sample size to determine the value of routine vestibular evaluation in children with sensorineural hearing loss and its potential benefit on the clinical outcome of these patients along with VEMP testing.

Comparison of tone burst versus logon stimulation for vestibular evoked myogenic potentials

The following study has been carried out to compare the effectiveness of logon and tone burst acoustic stimulation to elicit vestibular evoked myogenic potential (VEMP) responses. The methods and the subjects include 31 healthy adult volunteers (62 ears) who were enrolled in this study. Two different acoustic stimuli, logon (L-VEMP) and tone burst (T-VEMP), were used to elicit VEMP responses in each subject. Bilateral recordings with simultaneous binaural acoustic stimulations were used during VEMP recordings. During the recording period, the subjects were in supine position with their head elevated. The results observed were that the response rate of p1n1 wave was 91.9% for L-VEMP and 88.7% for T-VEMP. The response rate of n2p2 wave was 80.6% for L-VEMP, and 75.8% for T-VEMP. There were no significant differences between the two groups with respect to the latencies of p1, n1, n2 and p2, p1n1 and n2p2 interval, and p1n1 and n2p2 amplitude. The conclusion was that there was no difference between logon and tone burst stimulation with respect to VEMP response rates and VEMP parameters. Therefore, they are not superior to each other.

The effect of saccular function on static balance ability of profound hearing-impaired children

OBJECTIVE

Researches have shown that in clinical practice, balance disorders in children with congenital or early acquired severe to profound hearing loss are probable. The purposes of present study were to specify the percentage of vestibular evoked myogenic potential (VEMP) and an acoustically evoked, short latency negative response (ASNR) recordings and the relation between their presence and static balance ability and postural control of children with profound sensorineural hearing loss (SNHL).

METHODS

Thirty children with profound SNHL, with an average age of 6.93 years, underwent the VEMP and auditory brainstem response (ABR) tests. Both VEMP and ABR were recorded at the threshold level through air-conduction stimulation via an insert receiver. The static balance performance of the hearing-impaired children was tested with six exercises and compared with that of 30 age- and sex-matched normal-hearing children as controls.

RESULTS

VEMP was recorded in 53.3% of ears and ASNR in 40.0%. VEMP was revealed in all ears with ASNR, and a significant correlation was shown between their presence (p=0.005) and also between the ASNR wave latency and P1 (p=0.0001) and N1 (p=0.004) wave amplitude of VEMP. There was a significant correlation between the presence of VEMP and ASNR with the performance of the children in two static balance skills, namely standing on one leg with eyes open on a line and the same practice on the balance beam (p≤0.008).

CONCLUSION

There was a close relation between the presence of VEMP and ASNR. Additionally, when ASNR was present, the recording of VEMP could be expected. Successful performance in the static balance exercises with reduced vestibular and somatosensory inputs increased the possibility of the recording of ASNR and VEMP.

Comparison of head rotation versus head elevation methods for vestibular evoked myogenic potentials by using logon stimulus

OBJECTIVES

To compare vestibular evoked myogenic potentials (VEMP) between two different methods, head rotation (HR) with unilateral recording and head elevation (HE) with bilateral simultaneous recording.

SUBJECTS AND METHODS

Twenty-eight healthy children (56 ears) were involved in the study. The subjects were tested in two different positions: head rotation (HR) method and head elevation (HE) method. Right- and left-side recordings were made separately in HR method and simultaneously in HE method. Logon type stimulus with 120dB Hl intensity was used to trigger VEMPs in both methods.

RESULTS

The response rate was 80.4% for HR method and 89.3% for HE method (p>0.05). There was no significant difference between the two groups with respect to P1 latency, N1 latency, and P1-N1 interval. The mean P1-N1 amplitude of HE method was higher than HR method (p<0.05). There were very strong positive correlations between two methods regarding N1 latency and P1-N1 interval (r: 0.849 and 0.841, respectively).

CONCLUSION

Bilateral simultaneous VEMP recording in head elevation position by using logon stimulus is a practical way to evaluate vestibulocollic reflex in children and it gives superior results than unilateral recording with head rotation position.

The effects of logon versus click on vestibular evoked myogenic potentials

CONCLUSION

Logon is superior to click to trigger larger and more consistent vestibular evoked myogenic potentials (VEMPs).

OBJECTIVES

To record and compare the parameters of VEMPs evoked by bone- and air-conducted logon (l-VEMPs) and click (c-VEMPs).

SUBJECTS AND METHODS

Air- and bone-conducted l-VEMPs and c-VEMPs were recorded in 28 normal ears with an Amplaid MK12 (Amplaid, Milan) equipment.

RESULTS

VEMPs response rate was 100% with both air-conducted logon and click, while l-VEMPs showed a higher response rate (79%) in comparison with c-VEMPs (21%) with bone-conducted stimuli. A significant (p<0.05) increase of P1, N1 and P1-N1 amplitude and augmented P1 and N1 latencies were noticed in l-VEMPs with respect to c-VEMPs.

Clinical application of vestibular evoked myogenic potentials in healthy newborns

OBJECTIVE

Auditory and vestibular functions have critical importance in infancy because they may affect motor and mental development. We aimed to determine the normal values of the vestibular evoked myogenic potential (VEMP) parameters to provide a reference for further research regarding the early diagnosis of vestibular dysfunction in newborns.

METHODS

Twenty-four term newborns (12 girls, 12 boys), with birth weights greater than 2500 g and Apgar scores higher than 7 at 1 min, were studied. Tympanometry, auditory-evoked brainstem responses, transient-evoked otoacoustic emissions, and VEMP recordings were assessed in all subjects during fourth week after birth.

RESULTS

All newborns passed the audiologic evaluation, and biphasic waveforms of the VEMP were obtained in all 48 tested ears. Mean latencies of p13, n23, and p13-n23 intervals were 13.7+/-1.1, 20.5+/-1.6, and 7.1+/-2.1 ms, respectively. The mean amplitude value was 22.6+/-18.4 microV. There were no significant differences in latency values or amplitudes with regard to sex or side of ear tested in newborns.

CONCLUSIONS

VEMP may easily be used for early evaluation of vestibular dysfunction in newborns. Because results may differ owing to test techniques and age, every laboratory should have its own normal values.