Pediatric Bilateral Vestibular Hypofunction: A Review of 26 Cases

Abstract

Objective

Peripheral bilateral vestibular hypofunction (BVH) is a rare condition that is well‐studied in the adult population, whereas characterization in children has been limited. We report a pediatric cohort of patients with BVH at a multidisciplinary, tertiary care pediatric vestibular clinic.

Methods

A record review of 832 patients with balance‐related complaints in our center was conducted. Multidisciplinary evaluations in Otolaryngology, Physical Therapy (PT), and Audiology were reviewed for each subject, and data were entered into a REDCap database for further analysis.

Results

Twenty‐six individuals met diagnostic criteria for BVH. The cohort consisted of 17 females and nine males, with a mean age of 5.24 years (1.41–17.35; SD 3.97). Thirteen subjects had diagnoses of one or more concurrent neurodevelopmental syndromes. Sensorineural hearing loss (SNHL) was present in 21 (80.8%) subjects, of which 17 were profound in severity and 14 had undergone cochlear implant surgery. Seventeen (65.4%) children were able to complete vHIT testing, revealing reduced lateral semicircular canal (SCC) gains bilaterally in 11 cases. Twenty‐one (80.8%) patients received recommendation for PT services, of which 15 were for vestibular therapy specifically. Patients who completed their course of vestibular PT achieved improved functional goal outcomes and discharge from therapy in nine of 11 (81.8%) cases.

Conclusion

We present a case series of pediatric patients with bilateral vestibular hypofunction. BVH in this population is often associated with SNHL and comorbid congenital or neurodevelopmental diagnoses. Vestibular physical therapy may provide a significant improvement in quality of life for patients.

Level of Evidence

4 Laryngoscope, 135:2176–2181, 2025

We report a pediatric cohort of patients with peripheral bilateral vestibular hypofunction (BVH) at a multidisciplinary, tertiary care pediatric vestibular clinic. Patients frequently had history of sensorineural hearing loss and developmental delays, with associated vestibulo‐ocular reflex (VOR) impairments during testing. Vestibular physical therapy may provide a significant improvement in qualify of life for patients.

INTRODUCTION

An estimated 3.5 million children in the United States experience symptoms of dizziness and imbalance; however, the diagnosis of vestibular disorders in children is challenging. Children experiencing vestibular dysfunction may be unable to articulate their symptoms and participate effectively in vestibular testing.^{1, 2, 3} In the pediatric population, it has also been noted that diagnoses for the same clinical presentation vary depending on the type of provider seen and vestibular testing modalities available.^{1, 4} These obstacles make diagnosing pediatric vestibular disorders especially difficult, and less than half of children with imbalance receive a definitive diagnosis. ¹ This diagnostic gap underscores the need for investigation into specific etiologies of imbalance in children.

One such etiology is peripheral bilateral vestibular hypofunction (BVH), a rare but devastating chronic condition characterized by reduced or absent function of the peripheral vestibular system bilaterally.^{5, 6, 7, 8} Affected individuals experience a variety of symptoms, including severe imbalance, gait disruption, oscillopsia, compromised spatial orientation, and cognitive deficits.^{9, 10} BVH is often under‐ or misdiagnosed in adults, with estimates of incidence ranging from 28 to 85 cases per 100,000 adults.^{5, 6, 11} Though physical impairments can be debilitating, it is possible to compensate for loss of peripheral vestibular functioning by training individuals to utilize other visual and proprioceptive information.^{12, 13, 14, 15}

There has been significant academic interest in pediatric vestibular disorders, including diagnostic criteria, management, and considerations of vestibular assessment that are unique to this population.^{2, 16, 17, 18, 19} While BVH has been thoroughly described in the adult vestibular literature, its characteristics and manifestations in the pediatric population specifically have not been well studied. The purpose of this investigation is to report our experience with pediatric BVH at a multidisciplinary vestibular clinic at a tertiary care center, and to evaluate the incidence, clinical characteristics, and management of this entity.

MATERIALS AND METHODS

Study Design

This study was approved by the institutional review board of the Children's Hospital of Philadelphia. A retrospective chart review was performed in a multidisciplinary pediatric vestibular clinic at a tertiary care center. A total of 832 pediatric patients with balance‐related complaints were evaluated over a 5‐year period from 2017 to 2022. Medical records were reviewed, inclusive of relevant history, pediatric vestibular physical therapy evaluation, and audiovestibular testing results. Each patient underwent comprehensive vestibular testing according to their age and ability to participate. For the focus of this case series, we chose to highlight testing that evaluates the vestibulo‐ocular reflex (VOR), including video head impulse testing (vHIT) and rotary chair testing.

Definition of Bilateral Vestibular Hypofunction

There are a variety of definitions of BVH employed in the adult population, incorporating vestibular testing results, reported symptoms, and clinical presentation, but no gold standard testing for diagnosis currently exists.^{6, 11} Due to the variation of patient presentations and abilities to undergo involved testing at an initial visit, we defined BVH as meeting at least one of three criteria: (1) bilateral low gain on vHIT; (2) bilateral absent or impaired VORs on rotary chair testing; or (3) corrective saccades on head thrust (HT) testing during vestibular physical exam. All patients diagnosed with BVH according to these criteria were included in this review.

Statistical Analysis

Due to the small size of this cohort, statistical analyses provided in this report are descriptive and were conducted in Excel.

RESULTS

Of the 832 records evaluated, 26 subjects (3.12%) who met diagnostic criteria for BVH were identified (Table I). The cohort consisted of 17 females and nine males, with a mean age of 5.24 years (1.41–17.35; SD 3.97y). Thirteen of these children had diagnoses of one or more concurrent neurodevelopmental syndromes, including CHARGE syndrome (4), autism spectrum disorder (3), congenital cytomegalovirus infection (3), Waardenburg syndrome (1), Usher's syndrome (1), and Dandy–Walker malformation (1). One additional child presented with a constellation of findings concerning for an underlying syndrome and was undergoing extensive diagnostic workup at the time of this study. The four subjects with CHARGE syndrome each had inner ear abnormalities identifiable on imaging. Findings included absent superior or lateral semicircular canals (SCCs) bilaterally, dysplastic posterior SCCs, and right cochlear nerve aplasia with an absent left oval window. Twenty‐one subjects (80.8%) had sensorineural hearing loss (SNHL) in at least one ear, of which 17/21 (81%) were profound in severity and 15/21 (71.4%) individuals had bilateral SNHL. Hearing loss was associated with autosomal recessive MYO15A mutation in one patient. Fourteen patients underwent cochlear implant surgery, seven used hearing aids, and three children used ear‐level remote microphone systems. Two patients had normal hearing on evaluation and did not require any hearing technology.

TABLE I.

Demographics of Patient Population.

Demographics of BVH Patient Cohort (n = 26)
Age Group at Visit (N, %)
<3 years	10 (38.5%)
3–10 years	13 (50%)
>10 years	3 (11.5%)
Age (Mean, Range, SD)	5.24 (1.41–17.35, 3.97)
Sex (N, %)
Female	17 (65.4%)
Male	9 (34.6%)
Race/Ethnicity (N, %)
Caucasian Non‐Hispanic	14 (53.8%)
Caucasian Hispanic	2 (7.7%)
Black or African American	2 (7.7%)
Multiple Selections	2 (7.7%)
Asian (excluding Indian)	1 (3.8%)
Other	4 (15.4%)
Not Indicated	1 (3.8%)
Hearing Loss (N, %)
SNHL*	21 (80.8%)
Conductive	2 (7.7%)
Mixed	1 (3.8%)
Normal	2 (7.7%)
Developmental Motor Delay (N, %)	18 (69.2%)
Comorbid Diagnoses (N > 1, %)
Genetic Syndromes**	7 (26.9%)
Hypotonia	7 (26.9%)
Otitis Media	5 (19.2%)
Inner Ear Abnormalities	4 (15.4%)
Vertigo	3 (11.5%)
Vestibular Migraine	3 (11.5%)
Ataxia	3 (11.5%)
Autism	3 (11.5%)
CMV	3 (11.5%)
History of PT/OT Services (N, %)	18 (69.2%)
PT Recommended (N, %)	21 (80.8%)

^*Of patients with SNHL, 17/21 (81%) were of profound severity.

^**Genetic syndromes included CHARGE (N = 4), Waardenburg (N = 1), Usher's (N = 1), and ARC (N = 1).

Of the 26 children meeting BVH criteria at the time of our review, 17 (61.5%) were able to complete lateral vHIT testing, with nine also completing anterior and posterior canal vHIT testing. Average final gain values for the lateral SCCs were 0.48 on the left (SD 0.21, range 0.12–0.85), and 0.52 on the right (SD 0.30, range 0.08‐1). Reduced lateral gain was defined as a value less than 0.7 in accordance with audiology standard practice. Of these 17 patients, 11 (64.7%) exhibited reduced lateral gain bilaterally, meeting our criteria for BVH. Five patients (29.4%) exhibited normal gain in at least one direction. Of note, one patient's vHIT data were not saved due to an electronic error during evaluation. A breakdown of average lateral SCC vHIT data by individual latencies and mean gain values for all SCCs are included in Tables S1 and S2, respectively.

Nine patients were unable to complete vHIT testing at their vestibular clinic evaluation due to developmental level or goggle intolerance. Seven of these patients, in addition to the five patients with insufficient vHIT results, met our BVH criteria through abnormal rotary chair findings during evaluation. The remaining two patients, unable to tolerate rotary chair testing, were diagnosed solely via visible bilateral corrective saccades on HT physical examination. Of the nine patients who did not complete vHIT initially, only one completed a follow‐up appointment and vHIT testing, with confirmatory findings. Only five patients were able to complete vestibular evoked myogenic potential (VEMP) testing.

Two‐thirds of this cohort completed and performed poorly on developmental motor scales during initial evaluation. The Peabody Motor Development Scale (PDMS) was utilized most frequently, with 15 patients scoring on average at the 19th, 9th, and 13th percentiles for Stationary, Locomotive, and Object Manipulation domains, respectively (Table II). When patients did not complete motor scale testing, providers often cited a lack of ability to participate. Eighteen children had developmental motor delay (69.2%), 10 (38.5%) had hypotonia at the time of presentation, and two additional patients had documented histories of hypotonia that had resolved prior to evaluation. Eighteen (69.2%) patients were receiving physical therapy prior to presentation, however, only one subject had received vestibular‐focused physical therapy in the past.

TABLE II.

Quantifying Physical Therapy Evaluations.

Average Peabody Developmental Motor Scale (PDMS) Percentile Scores
	Stationary	Locomotive	Object Manipulation
Evaluation (N = 15)	19.1	9.1	13.27
Evaluation subset (N = 4)	7.3	2.3	4.6
PT discharge (N = 4)	19.5	6.3	12.3

Average initial evaluation scores were calculated for the full cohort (N = 15), as well as just the patients with available post‐PT assessments (N = 4), for comparison purposes.

Based on results of vestibular testing and the overall functional status of subjects, 21 (80.8%) received recommendation for PT services. Fifteen (71.4%) of these recommendations included formal vestibular physical therapy, and six (28.6%) were only for continuation of therapies in various settings, including school, Early Intervention (EI), and patients' primary PT/OT offices. Five patients did not receive a recommendation for PT services due to normal functional assessments (3), deemed fit for continuation of home exercise program (1), or deferred PT due to upcoming CI surgery (1). This final patient was eventually directed to continue EI‐based PT. Of note, one patient deemed fit for vestibular therapy was given home exercise program instructions as they lacked appropriate resources near their home, and another patient is currently undergoing PT for vestibular migraines prior to possible BVH‐focused therapy.

Success in vestibular physical therapy was based primarily on functional measures. Of 11 patients with available vestibular PT visit records, nine (81.8%) met their therapy goals and were discharged safely with significant functional improvements. Of the remaining two patients, one made mild improvement over four sessions and was lost to follow‐up, and one patient continues in therapy with minimal improvement. Common goals achieved in PT included: climbing stairs independently (N = 7, 63.6%), navigating uneven surfaces with reduced falls (N = 5, 45.5%), and improved running and jumping abilities (N = 5, 45.5%). Overall, only four patients with verified PT participation had a repeated PDMS score at the end of their treatment course. These specific individuals demonstrated a modest increase from average 7th, 2nd, and 4th percentiles for the three domains during evaluation to 9th, 6th, and 12th percentiles at PT discharge (Table II). One patient completed a repeat Bruininks‐Oseretsky Test (BOT‐2) assessment, increasing from the 8th percentile for coordination and 16th percentile for strength/agility during evaluation, to a 50th percentile gross motor score at PT discharge. Seven patients recommended for physical therapy did not pursue this option through an Epic EMR‐linked center and the impact of treatment, if received, is unknown. Each patient and family in the cohort were counseled regarding environmental safety measures such as minimizing uneven surfaces and low light conditions.

DISCUSSION

We report the first case series describing pediatric BVH in the literature, along with a limited evaluation of clinical outcomes in this rare condition. Pediatric BVH, like adult BVH, remains a rare cause of vestibular dysfunction and imbalance. BVH was identified in only 3.13% of all pediatric patients evaluated in a multidisciplinary vestibular clinic, and most of these patients presented in early childhood. In this cohort, half of cases were associated with at least one underlying syndrome and 17 (65.4%) children had concurrent profound SNHL.

Association With Sensorineural Hearing Loss

The association between SNHL and general vestibular dysfunction exhibited in this cohort is well‐documented in both the pediatric and adult literature.^{3, 20, 21, 22, 23, 24} The prevalence of vestibular impairment in children with SNHL is estimated to be 50–70% and correlates with both the degree of hearing loss and the etiology of SNHL.^{3, 23, 25} An association between SNHL and BVH in particular has been recognized in the adult population, with an estimated 34% of affected adults having concurrent hearing loss.^{6, 26} Our pediatric cohort demonstrated a much higher prevalence of SNHL with 65.4% of patients having concurrent profound SNHL in one or both ears. The preponderance of SNHL in our cohort may be related to the high proportion of subjects with congenital syndromes. Thus, in children with bilateral SNHL and concern for imbalance, clinicians should maintain a high index of suspicion for a co‐diagnosis of BVH. ²³

It is also important to note that 14 patients had at least one cochlear implant at the time of evaluation. While cochlear implantation has a documented association with vestibular disruption in children with SNHL, it has not been specifically associated with BVH.^{24, 27, 28} Furthermore, evidence supports a greater likelihood of vestibular impairment with more severe hearing loss, and our cohort experienced BVH symptoms prior to CI implantation.^{23, 29} Within our center specifically, we do not require a vestibular evaluation prior to CI implantation. While some CI patients did complete optional vestibular testing, all patients with history of CI who were identified on chart review to have BVH presented to our center for primary concern of imbalance or gross motor abnormalities, independent of CI evaluation. Our center has evaluated many children with SNHL who did not receive a diagnosis of BVH. No patients in our study were found to have BVH due to CI evaluation alone.

Association With Congenital Syndromes

In many cases, the etiology of BVH is elusive even after diagnosis. In the adult population, an estimated 20%–51% of cases of BVH remain idiopathic.^{6, 30} In the pediatric cohort studied, however, several subjects carried diagnoses of underlying genetic syndromes or other neurodevelopmental conditions. Some of these syndromes have been associated with vestibular dysfunction, although only some have been characterized as contributing to BVH.^{31, 32} Within our cohort, six subjects had congenital syndromes with known vestibular manifestations, including CHARGE syndrome, ARC syndrome, and Usher's syndrome. Similarly, congenital CMV infection has a known association with both SNHL and vestibular impairment and was diagnosed in three children in this cohort.^{33, 34} In contrast, two patients had genetic conditions not classically associated with a vestibular phenotype, including Waardenburg syndrome and autosomal recessive mutations in MYO15A.

The difficulty of diagnosing pediatric vestibular disorders is compounded in children with neurodevelopmental disorders or other congenital syndromes, as symptoms like posturomotor instability, poor fine motor skills, and delayed developmental milestones can overlap. ³¹ Though awareness of pediatric vestibular disorders is increasing, vestibular testing is not part of the standard evaluation for these disorders, and developmental delays or functional deficits may be attributed to their underlying condition without consideration of a vestibular etiology.^{3, 31, 32} While further study is required to the relative contribution of vestibular dysfunction to a child's overall clinical picture and functional status, identifying BVH in these children may provide opportunities for targeted therapies.

Association With Developmental Delay and Hypotonia

Managing vestibular symptoms in children is especially important, as vestibular dysfunction from any etiology occurring during critical developmental periods can contribute to delays across multiple developmental domains.^{31, 35, 36} As the vestibular system is critical to an individual's ability to maintain posture and coordinate movement, it is unsurprising that children with BVH and other vestibular impairments exhibit delays in achievement of developmental milestones. ³⁶ Examples of impairments often include delayed acquisition of head control, sitting, and independent walking.^{31, 35} This trend was seen in our cohort with 18 children exhibiting developmental delay.

It is also important to note the potential contributions of hypotonia to the motor delays seen in our cohort. Associations between hypotonia, delayed acquisition of milestones, and vestibular dysfunction have been previously reported.^{37, 38} It is unsurprising that the 10 children with hypotonia at time of evaluation had difficulty with motor tasks and balance. ³⁹ For the two children with prior histories of hypotonia, however, their impaired balance and motor functioning persisted beyond resolution of their hypotonia. This supports a vestibular etiology for their difficulties and suggests that addressing the vestibular dysfunction has meaningful potential for improving motor functioning.

In addition to motor delays, there is also evidence to suggest that bilateral vestibular impairment during critical developmental windows in childhood can impact both spatial and nonspatial cognitive functioning.^{31, 36, 40} The vestibular system is involved in visuospatial processing and directing eye movements, so children with gaze instability or oscillopsia have difficulties with reading, drawing, writing, and mathematics resulting in poor academic performance.^{31, 41, 42} These impairments have also been shown to extend into the social and emotional domains by impacting a child's self‐esteem, anxiety, and social functioning.^{31, 43, 44}

The complex interplay between vestibular dysfunction, developmental delay, and underlying syndromes in our cohort pose interesting questions. It remains unclear whether vestibular dysfunction is a common underlying etiology of these children's impairments or an unrecognized contributor responsible for some portion of their overall deficits. Thus, identifying these deficits through vestibular testing may allow for timely intervention and the possibility of long‐term improvements across multiple functional domains and quality of life.

Management of BVH

Vestibular physical therapy retrains individuals to integrate other sensory cues from the environment to compensate for vestibular deficits. ¹³ While such rehabilitation has been employed successfully for adults with BVH and other pediatric vestibular disorders, its efficacy in children with BVH remains uncertain.^{22, 27, 45, 46} Within our study, nine of 11 patients with accessible vestibular PT records completed treatment with improvements in various functional outcomes. Notably, most of these patients reached discharge from vestibular PT based on achieved functional goals, rather than the improvement of quantitative metrics such as PDMS scores. This highlights the importance of individualized assessment and partnering with families to identify personal metrics for progress. While the small sample size of this cohort limits the ability to draw general conclusions, the experiences of these patients raise the possibility that vestibular rehabilitation could be an effective intervention for children with BVH and demonstrates the need for further research in this area.

Limitations

Our study is limited by inconsistent completion of vestibular evaluation modalities across patients. This aligns with current literature regarding pediatric vestibular screening, which lacks both a standard evaluation protocol and a defined clinical threshold for the evaluation of BVH.^{47, 48, 49, 50, 51, 52} While we attempted vHIT testing for all three SCCs, the horizontal SCC was prioritized in visits with limited goggle tolerance or large goggle sizes leading to unreliable results for anterior and posterior canals. This is also in line with current literature, as appropriate goggle sizes for very small children are not yet available and the horizontal canal is canonically prioritized, including in BVH evaluation.^{49, 51, 52, 53}

While neurodevelopmental comorbidities and young age posed functional limitations to subject testing, our center's evaluation protocols also faced barriers during the time of the study. For example, VEMPs were not FDA approved for clinical use until 2018, 1 year after the start of this study. Furthermore, VEMPs held no formal CPT codes for testing until 2021, and several insurance plans in Pennsylvania and New Jersey, including PA Medicaid, denies this coverage.

Future Directions

While it is understood that SNHL, neurodevelopmental disorders, and other genetic syndromes are associated with vestibular dysfunction, individuals with BVH may represent a specifically impaired subset of this population. It is not known how many pediatric patients fitting this clinical picture may have undiagnosed BVH causing functional deficits that are otherwise attributed to motor or developmental delay alone. Defining this unrecognized population through effective diagnosis of BVH may provide opportunities for earlier, targeted vestibular interventions that complement these children's therapeutic plans and improve overall functioning. Further investigation is necessary to elucidate the interactions between hearing loss, congenital syndromes, development, and vestibular dysfunction in children with BVH and the impact of vestibular physical therapy on these children's symptoms and quality of life.

CONCLUSION

In this study, we present the first known case series of pediatric bilateral vestibular hypofunction with multidisciplinary evaluation. Pediatric BVH, like adult BVH, is a rare cause of vestibular dysfunction and imbalance. In this cohort, BVH was associated with SNHL, congenital syndromes, and developmental delay. Because of the complex interplay of these factors, vestibular testing and multidisciplinary evaluation confers a more thorough understanding of their condition and functional deficits. Despite the multifactorial nature of the condition in most patients, targeted vestibular physical therapy can be considered in children with this clinical picture and most patients do benefit from participation.

Supporting information

Supplementary Table S1. Average of Individual Latency Lateral vHIT Datapoints Across Patients. Table displays mean cohort vHIT gain data at individual latencies for the lateral SCCs, for both right and left sides. Note: One patient's data was not saved due to an electronic error at the time of testing. Two patients' data outputs only included values at 60 ms.

Supplementary Table S2. Descriptive vHIT Statistics for All Three Semicircular Canals Across Patients. Table displays mean, SD, and range of cohort vHIT gain data for all three SCCs, for both right and left sides. Note: One patient's data was not saved due to an electronic error at the time of testing. Reduced gain is defined by audiology standard practice as follows: lateral canal, <0.7; anterior canal, <0.55; posterior canal, <0.55.