Fifteen-minute consultation: The dizzy child.

Vestibular disorders are often overlooked in children and may cause significant morbidity. About a third of children presenting with problems in balance show a vestibular pathology and the overall prevalence of paediatric vertigo is about 5%. Appropriate diagnosis and holistic management can have a significantly positive impact on a child's quality of life and can be very rewarding. We present a structured approach to the assessment and management of a child presenting with dizziness in a general, non-neurological specialty or community paediatric outpatient setting.

Modernising vestibular assessment.

BACKGROUND: There is a high prevalence of dizziness, vertigo and balance symptoms in the general population. Symptoms can be generated by many inner-ear vestibular disorders and there are several diagnostic tests available that can help identify the site of the vestibular lesion. There is little consensus on what diagnostic tests are appropriate, with diagnostics either not completed or minimally performed, leading to missed diagnosis, unsatisfactory results for patients and costs to healthcare systems. METHODS: This study explored the literature for different neuro-vestibular diagnostic tests not currently considered in the traditional standard vestibular test battery, and examined how they fit effectively into a patient care pathway to help quickly and succinctly identify vestibular function. RESULTS: A vestibular patient care pathway is presented for acute and subacute presentation of vestibular disorders. CONCLUSION: An accurate diagnosis following a rigorous anamnesis and vestibular testing is paramount for successful management and favourable outcomes.

Cochleovestibular Phenotype in a Rare Genetic MED13L Mutation.

The gene MED13 participates in transcription. The MED13L gene is a paralog of MED13 that is involved in developmental gene expression. Mutations in the gene have been shown to result in a heterogenous phenotype affecting several physiological systems. Hearing loss has been reported very rarely, and vestibular weakness has never been reported in the condition. In this report, we present a mutation of MED13L in c.1162A > T (p.Arg388Ter), where we detail and describe a cochleovestibular phenotype with objective vestibulometry for the first time. The child showed bilateral sloping sensorineural hearing loss, a bilateral vestibular weakness, and an inner ear vestibular structural abnormality on imaging. Early intervention with hearing aids and vestibular rehabilitation led to a favorable outcome in terms of speech, communication, and balance. We emphasize the importance of comprehensive audiovestibular assessment in children diagnosed with MED13L mutations for effective management of these children.

Suppression head impulse test in children-experiences in a tertiary paediatric vestibular centre.

The suppression head impulse paradigm (SHIMP) involves suppression of the vestibulo-ocular reflex (VOR) and anticompensatory saccades generated thereof. SHIMP is gaining importance to understand vestibular compensation with its different parameters (VOR gain/peak saccadic velocity PSV/latency of saccades). SHIMP studies are emerging in adults, but pediatric studies have hardly been performed. This study is a retrospective case note audit over a period of 2 months in a tertiary pediatric vestibular center in the United Kingdom to investigate whether SHIMP is safe/robust to be used in children conforming to existing standards/norms in normal children and whether it yields any meaningful inferences in pediatric vestibular hypofunction. This is the largest pediatric SHIMP study to date. A total of 44 referred children (6-18 years, female children>male children) with a range of complaints from dizziness, imbalance, motor incoordination, postural instability, and hearing loss were included, and their SHIMP parameters were measured. All children underwent comprehensive functional/objective audiovestibular assessments. Two groups were defined-Group A with normal vestibular function and Group B with abnormal vestibular function. The normal population showed an average SHIMP VOR gain of 0.98+/-0.08 and latency of overt saccades at 215.68+/-46.16 milliseconds agreeing with published evidence. The PSV of overt saccades was 315.39+/-56.30/s, and there was a gain asymmetry of 7.42+/-4.68 between the sides. Statistically significant differences with moderate/large effect sizes were observed between the groups in terms of VOR gain and PSV but not in saccade latencies. Covert saccades were rare in SHIMP, while overt saccades were observed in 100% of children. VOR gain difference between the head impulse paradigm (HIMP) and the SHIMP was significant as well. We observed statistically significant differences in side asymmetry of VOR gain between the groups. Furthermore, we identified a group of children with cerebellar lesions where overt saccades in SHIMP were rather low in number. Further research is recommended to investigate pediatric PSV, asymmetry, and inability to generate overt saccades that may suggest useful means to assess compensation and central function. We conclude that SHIMP yields valuable information and is a safe, easy to perform, and a reliable test that should be used in children to supplement HIMP.

Experience from the First Paediatric Vestibular and Balance Clinic in a Multiracial Asian Setting.

Objective: Paediatric vestibular and balance services have recently gained attention across the globe. We present our one-year experience exploring the aetiology of paediatric vestibular disorders in a recently established Paediatric vestibular and balance clinic. Methods: Children and adolescents under 18 referred to the Paediatric Vestibular and Balance Clinic for evaluation were included. Results: 74 children were included in this study (Mean age: 10.04 ± 3.9). We found a slight female predominance, n = 38 (51.35%). Abnormal vestibular function was observed in 60.8% of children. Vestibular migraine (VM) was the most common aetiologic cause, n = 35 (47.3%), followed by vestibular/balance delay (n = 11). Conclusion: The most prevalent cause of dizziness was VM, followed by vestibular delay found in children with isolated speech and language delay. We highlight the importance of awareness of various causes of dizziness in children amongst carers and physicians to diagnose and manage it early.

Multidisciplinary Care for Moebius Syndrome and Related Disorders: Building a Management Protocol.

Moebius syndrome is a collection of orofacial anomalies with highly variable features affecting many different systems but characterised by bilateral facial palsy and absent eye abduction. We largely regard Moebius syndrome as a diagnosis of exclusion. Lack of awareness and knowledge means that children often fall between services, leading to treatment delays and difficulty interfacing with social care and schools, with long-term impact on physical health and psychosocial development. We developed a multidisciplinary team comprising core clinicians (lead physician, geneticist, speech and language therapist, psychologist and specialist nurse) and an expanded group to encompass the other affected systems. The interactions between our specialties lead to the development of a treatment protocol, which we present. The protocol harnesses the aspects of care of children with a range of other rare diseases at a specialised paediatric centre and synthesises them into a holistic approach for MBS and related conditions. Management is sequenced on an "ABC-style" basis, with airway, feeding, vision and speech taking priority in the early years. We define management priorities as airway stabilisation with swallow assessment, ocular surface protection and maintenance of nutritional support. Management principles for issues such as speech, reflux, drooling and sleep issues are outlined. In later years, psychological support has a prominent role geared towards monitoring and interventions for low mood, self-esteem and bullying.

X-Linked Gusher Disease DFNX2 in Children, a Rare Inner Ear Dysplasia with Mixed Hearing and Vestibular Loss.

Conductive hearing losses are typically present in disorders of the external/middle ear. However, there is a rare group of inner ear conditions called third windows that can also generate a conductive hearing loss. This is due to an abnormal connection between the middle and the inner ear or between the inner ear and the cranial cavity. X-linked gusher disorder is an extremely rare congenital inner ear dysplastic syndrome with an abnormal connection due to a characteristic incomplete cochlear partition type III and an incomplete internal auditory meatus fundus. The disorder is inherited in an X-linked fashion due to the mutation of the POU3F4 gene. We present two siblings diagnosed with the condition and their long-term follow-ups. They both presented audiovestibular symptoms and showed progressive mixed losses and bilateral vestibular weakness. They were treated with cochlear implant, digital amplification and with vestibular rehabilitation. Significant others around them were involved in their journey with the medical team, and in both, a very favourable outcome was achieved. This is the first time that we have reported evolving audiovestibular function with vestibular quantification in X-linked gusher disorder and emphasize on the multidisciplinary holistic approach to manage these children effectively.

Vestibular Function in Children With Von Hippel-Lindau Disease.

Von Hippel-Lindau disease (VHL) is a rare autosomal dominant disorder. It is caused by a mutation in the tumor suppressor gene localized at 3p25-26. Endolymphatic sac tumors (ELSTs) are rare low-grade adenocarcinomas which can occur sporadically but are more commonly found in association with VHL disease. In this paper, we present 3 siblings who underwent comprehensive vestibular assessment following a genetic diagnosis of VHL, and review the literature on audiovestibular findings in VHL/ELST in children. This is the first time that newer objective vestibular function tests like the video head impulse test (vHIT), the suppression head impulse test (SHIMP), and the cervical vestibular evoked myogenic potential test (cVEMP) have been performed in children with VHL to yield meaningful information about vestibular function. Monitoring audiological function has been suggested for early detection of ELSTs. It remains to be seen whether monitoring of vestibular function in patients with VHL from an earlier age may yield valuable information about progression of the disease.

Double-Blind Randomized Trial on the Efficacy of the Forced Prolonged Position for Treatment of Lateral Canal Benign Paroxysmal Positional Vertigo.

OBJECTIVES/HYPOTHESIS: The need for class I and II studies on the efficacy of liberatory maneuvers in the treatment of lateral canal benign paroxysmal positional vertigo (LC-BPPV) motivated the present double-blind randomized trial on the short-term efficacy of the forced prolonged position (FPP). STUDY DESIGN: Double-blind, randomized controlled trial. METHODS: Two hundred twenty-one patients with unilateral LC-BPPV met the inclusion criteria for a multicentric study. Patients were randomly assigned to treatment by FPP (116 subjects) or sham treatment (105 subjects). Subjects were followed up at 24 hours with the supine roll test by blinded examiners. RESULTS: Among the sample, 67.4% and 32.6% of the patients showed respectively geotropic and apogeotropic variant of LC-BPPV. At the 24-hour follow-up, the effectiveness of FFP compared to the sham maneuver was, respectively, 57.8% versus 12.4% (P < .0001) in the total sample, 76.9% versus 11.3% (P < .0001) in the geotropic variant group, and 60.5% versus 17.6% (P = .0003) in the apogeotropic variant group, including resolution or transformation to geotropic variant. CONCLUSIONS: FPP proved highly effective compared to the sham maneuver. The present class 2 study of the efficacy of the FPP changes the level of recommendation of the method for treating LC-BPPV into a strong one. LEVEL OF EVIDENCE: 2 Laryngoscope, 131:E1296-E1300, 2021.

Alexander Crum Brown: A Forgotten Pioneer in Vestibular Sciences.

Although vestibular anatomy was described in the Renaissance period, research in vestibular physiology began in the 1820s and was spearheaded by Purkinje and Flourens. This was subsequently expanded by Ménière, Helmholtz, Goltz, Mach, Breuer, Ewald, and Hogyes, who are regarded as the early pioneers in research on vestibular physiology in the 19th century. The relationship of endolymphatic flow and semicircular canal function is termed the Mach-Breuer hypothesis. What is less well known is that a Scottish chemist, Alexander Crum Brown, arrived at similar conclusions as Mach and Breuer at the same time quite independently. In fact, he pioneered several concepts in vestibular physiology that included pairing of semicircular canals for function, the vestibular pathway, optic fixation elimination in vestibular experimentation, the theory of motion intolerance, and study in deaf mutes for insights into vestibular pathology and vestibular compensation. This article is a tribute to this forgotten pioneer in vestibular research.

Audiovestibular Quantification in Rare Third Window Disorders in Children.

Third window disorders are structural abnormalities in the bony otic capsule that establish a connection between the middle/inner ear or the inner ear/cranial cavity. Investigated extensively in adults, they have hardly been studied in children. This study is a retrospective study of children (aged 5-17 years) diagnosed with rare third window disorders (third window disorders reported rarely or not reported in children) in a tertiary pediatric vestibular unit in the United Kingdom. It aimed to investigate audiovestibular function in these children. Final diagnosis was achieved by high resolution CT scan of the temporal bones. Of 920 children attending for audiovestibular assessment over a 42 month period, rare third windows were observed in 8 (<1%). These included posterior semicircular canal dehiscence (n = 3, 0.3%), posterior semicircular canal thinning (n = 2, 0.2%), X linked gusher (n = 2, 0.2%), and a combination of dilated internal auditory meatus/irregular cochlear partition/deficient facial nerve canal (n = 1, 0.1%). The majority of them (87.5%) demonstrated a mixed/conductive hearing loss with an air-bone gap in the presence of normal tympanometry (100%). Transient otoacoustic emissions were absent with a simultaneous cochlear pathology in 50% of the cohort. Features of disequilibrium were observed in 75% and about a third showed deranged vestibular function tests. Video head impulse test abnormalities were detected in 50% localizing to the side of the lesion. Cervical vestibular evoked myogenic potential test abnormalities were observed in all children in the cohort undergoing the test where low thresholds and high amplitudes classically found in third window disorders localized to the side of the defects in 28.5%. In the series, 71.4% also demonstrated absent responses/amplitude asymmetry, some of which did not localize to the ipsilesional side. Two children presented with typical third window symptoms. This study observes 2 new rare pediatric third window phenotypes and the presence of a cochlear hearing loss in these disorders. It emphasizes that these disorders should be considered as an etiology of hearing loss/disequilibrium in children. It also suggests that pediatric third window disorders may not present with classical third window features and are variable in their presentations/audiovestibular functions.

Functional and Objective Audiovestibular Evaluation of Children With Apparent Semicircular Canal Dehiscence-A Case Series in a Pediatric Vestibular Center.

Semicircular canal dehiscence is a bony abnormality in the otic capsule especially involving the superior semicircular canal. Since its identification in 1998, there is significant research regarding the pathology in the adult population. This condition generates a third window effect that is well-described in the literature. However, the entity is rare in the pediatric population with limited research. Difficulties encountered in children are obtaining a direct history that is essential for the diagnosis followed by neurovestibular tests that may be difficult to perform. This study presents observations regarding different clinical and diagnostic aspects of semicircular canal dehiscences in children as a retrospective audit in a tertiary pediatric vestibular center. Of 580 children assessed in a 30 months period undergoing comprehensive functional and objective audiovestibular assessment, 13 children (2.2%) were detected to possess radiological semicircular canal dehiscences (high resolution computed tomography scans at 0.625 mm slices reformatted in the axial, coronal and sagittal planes). The right superior semicircular canal was most commonly affected (66.6%). There were 4 bilateral semicircular canal dehiscences. Clinical suspicion of the condition was raised with reliable surrogate history from carers or from older children (100%), a mixed or conductive hearing loss (80% of hearing losses) in the presence of normal impedance audiometry (92.3%), normal transient otoacoustic emissions (84.6%) on the side of the dehiscence and the presence of replicable pathological saccades in the video head impulse test (76.9%). Disequilibrium symptoms and typical third window symptoms were absent or difficult to elicit in children (46.15 and 30.76% respectively). Only 3 (0.5%) fulfilled the adult criteria of a superior semicircular canal dehiscence syndrome. The abnormal video head impulse test characterized by pathological saccades may affect other non-dehisced ipsilateral canals. Semicircular canal dehiscences are rare in children but may be considered as an etiology for hearing losses and imbalance. Children with semicircular canal dehiscence may present differently from the classical superior semicircular canal dehiscence syndrome found in adults.