Audio-vestibular Findings in a Patient with Pelizaeus- Merzbacher Disease.

Pelizaeus-Merzbacher disease (PMD) is an X-linked recessive rare disease condition in which audiological deficit is also observed. A 4-year-old male child with PMD underwent an audiological evaluation. The results suggested normal middle ear and outer hair cells functioning, with only peak I of the auditory brainstem response present until 30 dBnHL. Further, the cervical vestibular evoked myogenic potential showed delayed latencies with normal amplitudes. In this case report, we attempt to explain the audio-vestibular test results and correlate them with the pathophysiology. This is the first report on the cervical vestibular myogenic potentials in patients with PMD.

Correction: Comprehensive Normative Data for Objective Vestibular Tests.

[This corrects the article DOI: 10.7759/cureus.40080.].

Does Binaural Stimulation Enhance Temporal Processing in Young Children?

Background and objective Temporal processing abilities help perceive signal changes over time. Efficient temporal processing is necessary for pitch perception, voice identification, and speech perception. It plays a significant role in language development. Internal redundancy of the central auditory nervous plays a role in processing sensory information. There is a need to gain more insights into the maturation of neural hardwiring that supports binaural temporal processing at a young age. The purpose of the present study was to evaluate the difference between monaural and binaural temporal processing in children aged 7-11 years. Methods Temporal processing was assessed using gap detection and temporal modulation transfer function (TMTF) tests. The tests were administered in 40 typically developing children with normal clinical auditory sensitivity. The maximum likelihood procedure (MLP), a MATLAB toolbox, was employed to deliver the stimulus. A multivariate analysis followed by post hoc analysis was performed to analyze the data. Results There was a significant difference between binaural and monoaural stimulation in children aged 7-11 years. However, there was no statistically significant difference between the right and left ears for gap detection threshold (GDT) and TMTF across all test frequencies. Conclusion Based on our findings, binaural stimulation enhances temporal processing in young children.

Comprehensive Normative Data for Objective Vestibular Tests.

INTRODUCTION:  Vestibular dysfunction is a debilitating disorder frequently encountered in neurological and otological settings. The vestibular system is a complex network between peripheral and central mechanisms. This innate complexity of the vestibular system necessitates objective test procedures for evidence-based diagnostic formulations and intervention. Objective tests aid in the evaluation of both peripheral and central vestibular pathologies. Establishing and availability of comprehensive normative data for these objective tests is crucial for clinicians and researchers alike. MATERIALS AND METHODS: This is a prospective study involving 120 participants (both males and females) aged between 18 and 55 years. All participants were right-handed individuals and had no significant medical history. On pre-set protocols, cVEMP (cervical vestibular evoked myogenic potential), oVEMP (ocular vestibular evoked myogenic potential), vHIT (video head impulse test), and VNG (videonystagmography) were done. RESULTS: While all participants (n=120) underwent cVEMP, oVEMP, vHIT, saccade, smooth pursuit, and optokinetic tests, only 109 participants consented to the caloric test. Each test's mean, standard deviation, median, quartile, and third quartiles have been recorded. A right-left comparison yielded no significant difference on cVEMP, oVEMP, caloric test, smooth pursuit, and optokinetic test. However, few vHIT and saccade parameters did reveal significant differences. DISCUSSION: This study presents comprehensive normative data for cVEMP, oVEMP, vHIT, caloric test on VNG, and oculomotor tests (smooth pursuit, saccade, optokinetic) on VNG. The test results were in concordance with previously published data. The significant difference between the right and left sides in vHIT may be because of the monocular goggles used for the testing. CONCLUSION: This study brings out the normative data for various vestibular tests on individuals aged between 18-55 years. This information could aid both clinicians and researchers working in the field of vestibular science.

Cervical and Ocular Vestibular Evoked Myogenic Potential Recovery in Susac Syndrome: A Case Report.

PURPOSE: Susac syndrome (SS) is a rare autoimmune disorder that affects the brain and the retina and causes unilateral or bilateral sensorineural hearing loss. Although vestibular dysfunction is reported in SS, limited information is available underlying the vestibular pathophysiology. METHOD: The diagnosis of SS was established based on symptoms and diagnostic tools such as magnetic resonance imaging and fundus fluorescein angiography. The audiovestibular evaluation was done on the seventh day of admission (Session 1) into the emergency unit, whereas the second and third evaluations were done at 3-month (Session 2) and 8-month (Session 3) follow-ups after discharge, respectively. The audiovestibular test battery consisted of routine audiological tests, auditory brainstem response, and vestibular evoked myogenic potentials (VEMPs; both cervical and ocular). RESULTS: We found unilateral sensorineural hearing loss and absent cervical VEMPs(cVEMPs) when testing the left ear during Session 1. In the following sessions, the unilateral hearing loss did not recover; however, cVEMPs were present bilaterally. The ocular VEMPs showed an increase in amplitude during Sessions 2 and 3. CONCLUSIONS: SS can selectively disrupt auditory and vestibular structures. It may present with unique findings of audiovestibular tests. A detailed audiovestibular evaluation may be essential in patients with SS. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.21513843.

Audiovestibular Dysfunction in Siblings with Charcot-Marie-Tooth Disease 4F: A Case Series.

BACKGROUND: Charcot-Marie-Tooth disease type 4F (CMT4F) is an autosomal recessive disorder with symptoms presenting in early adulthood. This clinical case series demonstrates atypical findings in cervical and ocular vestibular evoked myogenic potentials (VEMP) in siblings with CMT4F. PURPOSE: The aim of this study was to highlight the audiovestibular test findings in CMT4F. RESEARCH DESIGN: Case series study sample: 4 siblings, 3 of whom diagnosed with CMT4F. DATA COLLECTION AND ANALYSIS: Audiological test battery and electrophysiological tests comprising auditory brainstem response (ABR) and VEMP (both cervical and ocular) were performed in our patient population. RESULTS: Older siblings, in whom the hearing loss was present, manifested prolonged peak V latencies in ABR. Three out of four siblings with CMT4F showed prolongation of latencies on cervical and ocular VEMP. CONCLUSIONS: In many neurodegenerative conditions, prolongation of ABR peak latencies has often been reported in the literature. There have also been a few reports of prolonged VEMP peak latencies. This article reports prolongation of only VEMP peak latencies (in both cervical and ocular recordings). The youngest sibling had prolongation of VEMP latencies, with ABR peak latencies being normal. The assumption we put forth that CMT4F may affect the vestibular pathway first requires to be tested on a larger sample and by longitudinally studying the individuals with disease condition.

Audiovestibular findings in a 6 year old child with pilocytic astrocytoma - a case report.

Objective: Pilocytic astrocytoma commonly occurs in children and depending on the extension of the lesion may cause varied audiovestibular dysfunctions. However, audiovestibular findings are scarcely reported in the literature.Design: Audiovestibular testing was performed on a single subject on two occasions pre-surgically.Study sample: A 6 year old girl with pilocytic astrocytoma.Results: All audiological tests revealed normal findings except for the cervical vestibular evoked myogenic potential testing (cVEMP). The amplitude of cVEMP was higher in the lesion side indicating a hypersensitive vestibulocollic reflex pathway functioning.Conclusions: This case study reported a unique finding of hypersensitive cVEMP findings in the lesion side in a patient with pilocytic astrocytoma. The pathophysiological basis for this hypersensitivity is attributed to anatomical connections between the cerebellum and the vestibular nuclei through the inferior cerebellar peduncle.

Cervical Vestibular Evoked Myogenic Potential in Hypoglossal Nerve Schwannoma: A Case Report.

BACKGROUND: Schwannoma of the hypoglossal nerve is rare. This case report documents an atypical abnormality of the cervical vestibular evoked myogenic potential (cVEMP) in a patient with schwannoma of the hypoglossal nerve. The observed abnormality was attributed to the proximity of the hypoglossal nerve to the spinal accessory nerve in the medullary cistern and base of the skull. PURPOSE: To report cVEMP abnormality in a patient with hypoglossal nerve schwannoma and provide an anatomical correlation for this abnormality. RESEARCH DESIGN: Case report. STUDY SAMPLE: A 44-yr-old woman. DATA COLLECTION: Pure-tone and speech audiometry, tympanometry, acoustic stapedial reflex, auditory brainstem response, and cVEMP testing were performed. RESULTS: The audiological test results were normal except for the absence of cVEMP on the lesion side (right). CONCLUSIONS: A cVEMP abnormality indicating a compromised spinal accessory nerve was observed in a patient with hypoglossal nerve schwannoma. This case report highlights the importance of recording cVEMP in relevant neurological conditions and provides clinical proof for the involvement of the spinal accessory nerve in the vestibulocollic reflex pathway.