Vestibular Follow-up Program for Congenital Cytomegalovirus Based on 6 Years of Longitudinal Data Collection.

OBJECTIVES: Congenital cytomegalovirus (cCMV), the leading nongenetic cause of pediatric sensorineural hearing loss, can also affect vestibular function. Literature findings suggest clinical presentation of vestibular loss in cCMV to be as variable as the hearing loss. Still, probably due to the considerable additional burden it entails for both patients and diagnostic centers, longitudinal vestibular follow-up in cCMV is not well-established in clinical practice. Therefore, this study aims to propose an evidence-based vestibular follow-up program with proper balance between its feasibility and sensitivity. DESIGN: In this longitudinal cohort study, 185 cCMV-patients (mean age 3.2 years, SD 1.6 years, range 0.5-6.7 years) were included. Vestibular follow-up data were obtained through lateral video head impulse test (vHIT) and cervical vestibular evoked myogenic potential (cVEMP) evaluations around the ages of 6 months, 1 year, and 2 years. Around 3 and 4.5 years of age, data from vertical vHIT and ocular vestibular evoked myogenic potentials (oVEMP) were also collected. RESULTS: At birth, 55.1% (102/185) of patients were asymptomatic and 44.9% (83/185) were symptomatic. The mean duration of follow-up for all patients was 20.8 (SD 16.3) months (mean number of follow-up assessments: 3.2, SD 1.5). Vestibular loss occurred at some point during follow-up in 16.8% (31/185) of all patients. Six percent (10/164) of patients with normal vestibular function at first assessment developed delayed-onset vestibular loss; 80.0% (8/10) of these within the first 2 years of life. Vestibular deterioration was reported both in patients who had been treated with postnatal antiviral therapy and untreated patients. At final evaluation, both the semicircular and the otolith system were impaired in the majority of vestibular-impaired ears (29/36, 80.6%). Dysfunctions limited to the semicircular system or the otolith system were reported in 4 (4/36, 11.1%) and 3 (3/36, 8.3%) ears, respectively. The occurrence of vestibular loss was highest in patients with first trimester seroconversion (16/59, 27.1%) or with an unknown timing of seroconversion (13/71, 18.3%), patients with sensorineural hearing loss (16/31, 51.6%), and patients with periventricular cysts on magnetic resonance imaging (MRI) (7/11, 63.6%). CONCLUSIONS: Longitudinal vestibular follow-up, most intensively during the first 2 years of life, is recommended in cCMV-patients with vestibular risk factors (first trimester or unknown timing of seroconversion; sensorineural hearing loss; periventricular cysts on MRI). If those risk factors can be ruled out, a single evaluation early in life (around 6 months of age) might be sufficient. Both semicircular and otolith system evaluation should be part of the follow-up program, as partial losses were reported.

Predicting Early Vestibular and Motor Function in Congenital Cytomegalovirus Infection.

OBJECTIVES: Congenital cytomegalovirus (cCMV) can affect vestibular function, which is an important cornerstone for early motor development. This study aims to identify risk factors for early vestibular dysfunction with severe repercussions on the motor outcome. METHODS: This prospective cohort study included 169 cCMV-patients with complete vestibular assessment (lateral video Head Impulse Test and cervical Vestibular Evoked Myogenic Potentials) before the age of 18 months (mean 8.9, standard deviation 3.27 months). Motor results using the Alberta Infant Motor Scale were collected in 152 of these patients. Logistic and linear regression models were applied to identify risk factors for the vestibular and motor outcomes, respectively. RESULTS: The odds of developing early vestibular dysfunction were 6 times higher in patients presenting with hearing loss at birth compared to those born with normal hearing (p = .002). Within the latter group, significant predictors for vestibular dysfunction were (delayed-onset) hearing impairment at the time of vestibular testing (p = .003) and the presence of periventricular cysts on magnetic resonance imaging (p = .005). Remarkably, none of the patients infected during the third trimester of pregnancy (n = 14) developed early vestibular dysfunction. On average, vestibular-impaired patients had a z-score on the Alberta Infant Motor Scale that was 1.17 points lower than patients without vestibular deficit (p < .001). CONCLUSION: Early vestibular loss can have a significant adverse effect on motor development. Hearing and cranial imaging findings could facilitate the widespread implementation of a (targeted) vestibular assessment approach in the cCMV-population. LEVEL OF EVIDENCE: 3 Laryngoscope, 133:1757-1765, 2023.

Vestibular Infant Screening-Flanders: What is the Most Appropriate Vestibular Screening Tool in Hearing-Impaired Children?

OBJECTIVES: As children with sensorineural hearing loss have an increased risk for vestibular impairment, the Vestibular Infant Screening-Flanders project implemented a vestibular screening by means of cervical vestibular evoked myogenic potentials (cVEMP) at the age of 6 months for each child with hearing loss in Flanders (Belgium). Given that vestibular deficits can affect the child's development, this vestibular screening should allow early detection and intervention. However, less is currently known about which screening tool would be the most ideal and how vestibular impairment can evolve. Therefore, this study aimed to determine the most appropriate tool to screen for vestibular deficits, to assess the necessity of vestibular follow-up, and to set clinical guidelines for vestibular screening in children with hearing loss. DESIGN: In total, 71 children with congenital or early-onset sensorineural hearing loss were enrolled (mean age at first appointment = 6.7 months). Follow-up was provided at 6 months, 1, 2, and 3 years of age. Below three years of age, the video Head Impulse Test (vHIT) of the horizontal semicircular canals (SCC), the cVEMP, and the rotatory test at 0.16, 0.04, and 0.01 Hz were applied. At 3 years of age, the vHIT of the vertical SCC and ocular vestibular evoked myogenic potentials (oVEMP) were added. To evaluate early motor development, the Alberta Infant Motor Scale (AIMS) results at 6 months and 1-year old were included. RESULTS: At 6 months of age, the highest success rate was obtained with the cVEMP (90.0%) compared to the vHIT (70.0%) and the rotatory test (34.3-72.9%). Overall, vestibular deficits were found in 20.0% of the children, consisting of 13.9% with both SCC and otolith deficits (bilateral: 9.3%, unilateral: 4.6%), and 6.1% with unilateral isolated SCC (4.6%) or otolith (1.5%) deficits. Thus, vestibular deficits would not have been detected in 4.6% of the children by only using the cVEMP, whereas 1.5% would have been missed when only using the vHIT. Although vestibular deficits were more frequently found in severe to profound hearing loss (28.6%), characteristics of vestibular function were highly dependent on the underlying etiology. The AIMS results showed significantly weaker early motor development in children with bilateral vestibular deficits ( p = 0.001), but could not differentiate children with bilateral normal vestibular function from those with unilateral vestibular deficits ( p > 0.05). Progressive or delayed-onset vestibular dysfunction was only found in a few cases (age range: 12-36 months), in which the hearing loss was mainly caused by congenital cytomegalovirus (cCMV). CONCLUSIONS: The cVEMP is the most feasible screening tool to assess vestibular function in 6-months-old children with hearing loss. Although the majority of children with vestibular deficits are detected with the cVEMP, the vHIT seems even more sensitive as isolated SCC deficits are associated with specific etiologies of hearing loss. As a result, the cVEMP is an appropriate vestibular screening tool, which is advised at least in severe to profound hearing loss, but certain etiologies require the addition of the vHIT (i.e., cCMV, meningitis, cochleovestibular anomalies with or without syndromic hearing loss).

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.

Three Years of Vestibular Infant Screening in Infants With Sensorineural Hearing Loss.

OBJECTIVES: Although vestibular deficits are more prevalent in hearing-impaired children and can affect their development on many levels, a pediatric vestibular assessment is still uncommon in clinical practice. Since early detection may allow for timely intervention, this pioneer project has implemented a basic vestibular screening test for each six-month-old hearing-impaired infant in Flanders, Belgium. This study aims to report the vestibular screening results over a period of three years and to define the most important risk factors for abnormal vestibular screening results. METHODS: Cervical Vestibular Evoked Myogenic Potentials with bone-conduction were used as a vestibular screening tool in all reference centers affiliated to the Universal Newborn Hearing Screening Program in Flanders. From June 2018 until June 2021, 254 infants (mean age: 7.4 months, standard deviation: 2.4 months) with sensorineural hearing loss were included. RESULTS: Overall, abnormal vestibular screening results were found in 13.8% (35 of 254) of the infants. The most important group at risk for abnormal vestibular screening results were infants with unilateral or bilateral severe to profound sensorineural hearing loss (20.8%, 32 of 154) (P < .001, odds ratio = 9.16). Moreover, abnormal vestibular screening results were more prevalent in infants with hearing loss caused by meningitis (66.7%, 2 of 3), syndromes (28.6%, 8 of 28), congenital cytomegalovirus infection (20.0%, 8 of 40), and cochleovestibular anomalies (19.2%, 5 of 26). CONCLUSIONS: The vestibular screening results in infants with sensorineural hearing loss indicate the highest risk for vestibular deficits in severe to profound hearing loss, and certain underlying etiologies of hearing loss, such as meningitis, syndromes, congenital cytomegalovirus, and cochleovestibular anomalies.

Changes in Vestibular Function Following Pediatric Cochlear Implantation: a Prospective Study.

OBJECTIVES: Given the close interconnection between the auditory and vestibular end organs, the increasingly broad application of (bilateral) cochlear implantation (CI) in children raises concern about its impact on the vestibular function. Unfortunately, literature on this matter is inconclusive and subject to several limitations. Therefore, this study aimed to elucidate the impact of pediatric CI on the vestibular function in a large sample of children, representative for the current CI population. DESIGN: Fifty hearing-impaired children followed in the Ghent University Hospital were included in this prospective study. Twenty-seven patients underwent unilateral CI, and 23 were bilaterally implanted (9 sequentially, 14 simultaneously), adding up to 73 implanted ears. Children's median age at first implantation was 29 (range 8 to 194) months. Vestibular assessment was scheduled on average 2.8 months (SD: 3.6) before and 4.6 (SD: 4.0) months after implantation and consisted of video Head Impulse Testing of the lateral semicircular canals, rotatory testing (0.16, 0.04, and 0.01 Hz) and cervical vestibular evoked myogenic potential (cVEMP) testing with bone conduction stimulation. Caloric testing was added in children older than 3 years of age. RESULTS: Overall, group analysis in our sample of 73 CI-ears did not reveal any significant impact on the vestibular function, except for a significantly shortened ipsilateral N1 latency of the cVEMP responses (p = 0.027) after CI. Complete ipsilateral loss of function after implantation was seen in 5% (3/54) of all CI-ears on the video head impulse testing, in 0% (0/10) on the caloric test and in 2% (1/52) on the cVEMP, notably all patients deafened by a congenital cytomegalovirus infection. CONCLUSIONS: The impact of CI on the vestibular function in our dataset was limited. Therefore, the many advantages of simultaneous bilateral implantation may outweigh the risk for vestibular damage postoperatively. However, the impact on the vestibular function may be dependent on various factors (e.g., etiology of the hearing loss), and the clinical outcome is still difficult to predict. Vestibular assessment remains thus an important aspect in the pediatric CI population; first because the vestibular function should be considered in the decision-making process on (simultaneous or sequential bilateral) CI and second because it is essential to reveal a possible additional sensory deficit, allowing an opportunity for rehabilitation to improve the overall outcome of these children.

Vestibular Function in Children With a Congenital Cytomegalovirus Infection: 3 Years of Follow-Up.

OBJECTIVES: Congenital cytomegalovirus (cCMV) infection is the most common nongenetic cause of sensorineural hearing loss in children. Due to the close anatomical relationship between the auditory and the vestibular sensory organs, cCMV can also be an important cause of vestibular loss. However, the prevalence and nature of cCMV-induced vestibular impairment is still underexplored. The aim of this study was to investigate the occurrence and characteristics of vestibular loss in a large group of cCMV-infected children, representative of the overall cCMV-population. DESIGN: Ninety-three children (41 boys, 52 girls) with a confirmed diagnosis of cCMV were enrolled in this prospective longitudinal study. They were born at the Ghent University Hospital or referred from another hospital for multidisciplinary follow-up in the context of cCMV. The test protocol consisted of regular vestibular follow-up around the ages of 6 months, 1 year, 2 years, and 3 years with the video Head Impulse Test, the rotatory test, and the cervical Vestibular Evoked Myogenic Potential test. RESULTS: On average, the 93 patients (52 asymptomatic, 41 symptomatic) were followed for 10.2 months (SD: 10.1 mo) and had 2.2 examinations (SD: 1.1). Seventeen (18%) patients had sensorineural hearing loss (7 unilateral, 10 bilateral). Vestibular loss was detected in 13 (14%) patients (7 unilateral, 6 bilateral). There was a significant association between the occurrence of hearing loss and the presence of vestibular loss (p < 0.001), with 59% (10/17) vestibular losses in the group of hearing-impaired children compared to 4% (3/76) in the group of normal-hearing subjects. In the majority of the cases with a vestibular dysfunction (85%, 11/13), both the semicircular canal system and the otolith system were affected. The remaining subjects (15%, 2/13) had an isolated semicircular canal dysfunction. Sixty-one patients already had at least one follow-up examination. Deterioration of the vestibular function was detected in 6 of them (10%, 6/61). CONCLUSIONS: cCMV can impair not only the auditory but also the vestibular function. Similar to the hearing loss, vestibular loss in cCMV can be highly variable. It can be unilateral or bilateral, limited or extensive, stable or progressive, and early or delayed in onset. As the vestibular function can deteriorate over time and even normal-hearing subjects can be affected, vestibular evaluation should be part of the standard otolaryngology follow-up in all children with cCMV.

Vestibular Infant Screening (VIS)-Flanders: results after 1.5 years of vestibular screening in hearing-impaired children.

Due to the close anatomical relationship between the auditory and vestibular end organs, hearing-impaired children have a higher risk for vestibular dysfunction, which can affect their (motor) development. Unfortunately, vestibular dysfunction often goes unnoticed, as vestibular assessment in these children is not standard of care nowadays. To timely detect vestibular dysfunction, the Vestibular Infant Screening-Flanders (VIS-Flanders) project has implemented a basic vestibular screening test for hearing-impaired infants in Flanders (Belgium) with a participation rate of 86.7% during the first year and a half. The cervical Vestibular Evoked Myogenic Potentials (cVEMP) test was applied as vestibular screening tool to map the occurrence of vestibular (mainly saccular) dysfunction in this population. At the age of 6 months, 184 infants were screened. No refers on vestibular screening were observed in infants with permanent conductive hearing loss. In infants with permanent sensorineural hearing loss, a cVEMP refer rate of 9.5% was observed. Failure was significantly more common in infants with severe-profound compared to those with mild-moderate sensorineural hearing loss (risk ratio = 9.8). Since this is the first regional study with a large sample size and successful participation rate, the VIS-Flanders project aims to set an example for other regions worldwide.

Vestibular Infant Screening - Flanders: The implementation of a standard vestibular screening protocol for hearing-impaired children in Flanders.

OBJECTIVES: The Vestibular Infant Screening - Flanders (VIS-Flanders) project aims to implement and refine a vestibular screening protocol for all children with neonatal hearing loss in Flanders (Belgium) to limit the impact of a vestibular dysfunction on the motor, cognitive and psychosocial development of hearing-impaired children. METHODS: Each child with a confirmed neonatal hearing loss in Flanders will undergo a vestibular screening at the age of 6 months in the reference centers involved in the neonatal hearing screening program. The cervical Vestibular Evoked Myogenic Potential (cVEMP) test will be used as a screening tool. The test is short, child-friendly, feasible at a young age and highly correlated with motor and balance performance. The results of an extensive follow-up protocol at the Ghent University Hospital will enable further refinement of the screening protocol. RESULTS: Data collection in all reference centers has started since June 2018. This paper outlines the rationale for the screening and the set-up of this four-year project. CONCLUSIONS: Current available literature strongly favors vestibular assessment in congenitally hearing-impaired children. A standard vestibular screening for these children should lead to early identification of vestibular deficits and subsequent prompt referral for further motor assessment and rehabilitation, in order to limit the impact of a vestibular dysfunction in developing children and improve their quality of life.