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

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 ƞ² = 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.

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.

Paediatric vestibular assessment in French cochlear implant centres: Challenges and improvement areas

OBJECTIVE

Survey of paediatric vestibular activity in all 30 French paediatric cochlear implant (CI) centres to identify challenges and areas of improvement.

METHOD

All 30 French CI centres answered a 29-question questionnaire about their paediatric vestibular activity, equipment, and management in different clinical situations (e.g. vestibular assessment before a cochlear implantation or in cases of vertigo) at different ages.

RESULTS

Eighteen CI centres had dedicated paediatric vestibular clinics and 12 did not. Minimum age required for vestibular testing was 3 years in eight centres. Four vestibular tests stood out: caloric tests, video Head Impulse Test (vHIT), rotating chair, vestibular evoked myogenic potentials (VEMP). Depending on the centre's experience, the use of vestibular tests in clinical routine was very heterogeneous. Expert centres mostly used vHIT and cervical VEMP (in bone conduction) for assessments before the first cochlear implantation in 1-year-old children. Dizziness assessment in 4-year children was based on the use of vHIT, cervical VEMP on bone conduction, rotatory test, and caloric test. Ocular VEMP was rarely used.

CONCLUSIONS

Paediatric vestibular assessment requires specific expertise compared to adults. Due to a lack of specialised human resources, some centres may be unable to follow French paediatric CI guidelines. International recommendations could help standardise paediatric vestibular management and public health policies should be discussed to improve training and access for children.

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.