The Use of Subjective and Objective Audiologic Test Procedures in the Diagnosis of Multiple Sclerosis

Management of Sudden Sensorineural Hearing Loss in Multiple Sclerosis: A Comprehensive Case Report of a Patient with Bilateral Loss and Literature Review

In multiple sclerosis (MS), the occurrence of sudden sensorineural hearing loss (SSNHL) is considered rare, with reported cases predominantly being unilateral. Bilateral cases are even rarer. Here, we report a case of bilateral SSNHL in a 20-year-old male diagnosed with MS. The patient, undergoing corticosteroid therapy for the management of MS, additionally received an intratympanic dexamethasone injection; however, it could not achieve significant improvement. Subsequently, the systemic dosage was increased for one week, resulting in substantial hearing improvement in both ears after three months. A review of MS-related SSNHL cases from 1987 to 2022 revealed 39 ears in the literature, with only five ears showing no hearing recovery. A remarkable 87.2% exhibited restored hearing, presenting a more favorable prognosis compared with idiopathic SSNHL. Although there were slight variations in administration methods and duration, all documented treatment approaches involve systemic corticosteroids. In some instances, SSNHL manifested as the initial symptom of MS. When SSNHL occurs in MS, auditory brainstem response (ABR) tests may reveal prolonged abnormalities, making ABR testing effective in cases where MS is suspected following SSNHL. In conclusion, the treatment of MS-related SSNHL appears appropriate with systemic corticosteroids, showing a significantly superior prognosis compared with idiopathic SSNHL.

Effects of multiple sclerosis on the audio-vestibular system: a systematic review

OBJECTIVE

Systematically investigate the effects of multiple sclerosis (MS) on the audio-vestibular system.

METHODS

Systematic review of literature investigating audio-vestibular conditions in persons with MS (PwMS) aged ≥18 years. PubMed, Scopus, NICE and Web of Science were searched. Randomised controlled trials, and cohort, case-control, observational and retrospective studies in English, published from 2000 to 21 November 2021, evaluated PwMS with at least one outcome (pure tone audiometry, auditory brainstem response, otoacoustic emissions, cortical auditory evoked potentials, functional MRI assessing auditory function, vestibular evoked myogenic potentials, videonystagmography, electronystagmography, posturography, rotary chair, gaps in noise, word discrimination scores, duration pattern sequence test), were included. Study selection and assessments of bias were independently conducted by two reviewers using the Risk of Bias Assessment Tool for Non-randomized Studies, Newcastle-Ottawa Scale (NOS) and the NOS adapted for cross-sectional studies.

RESULTS

35 studies were included. Auditory function was evaluated in 714 PwMS and 501 controls, vestibular function was evaluated in 682 PwMS and 446 controls. Peripheral auditory function results were contradictory between studies; some found abnormalities in PwMS, and others found no differences. Tests of brainstem and central auditory functions were more consistently found to be abnormal in PwMS. Most vestibular tests were reported as abnormal in PwMS, abnormalities were either peripheral or central or both. However, quantitative analyses could not be performed due to discrepancies between studies in results reporting, test stimulus and recording parameters.

CONCLUSIONS

Although abnormal results on auditory and vestibular tests were noted in PwMS, specific effects of MS on the audio-vestibular system could not be determined due to the heterogeneity between studies that restricted the ability to conduct any quantitative analyses. Further research with consistent reporting, consistent stimulus and consistent recording parameters is needed in order to quantify the effects of MS on the auditory and vestibular systems.

PROSPERO REGISTRATION NUMBER

CRD42020180094.

Multiple sclerosis: a cause of sudden hearing loss

Sudden hearing loss is a clinical entity which has numerous aetiologies. In cases where the aetiology is not determined, evaluation and treatment of sudden hearing loss are very difficult. A case of probable multiple sclerosis with sudden hearing loss as the initial symptom is reported. The pure-tone audiometry showed a quasi-total sensorineural hearing loss in the left ear; the left side displayed only wave I in the auditory brainstem response (ABR). Electronystagmographic examination revealed hypometric dysmetria and saccadic pursuit abnormalities. Magnetic resonance imaging (MRI) showed high-intensity lesions with multiple foci. After steroid therapy, the patient's hearing loss, vertigo and visual problems improved, but the ABR findings remained unchanged. We have decided to present this case because of the interesting ABR finding revealing the presence of wave I and the absence of all other waves after the normalization of the hearing.

Evoked otoacoustic emissions and electrocochleography in a patient with multiple sclerosis

A 24-year-old woman with multiple sclerosis had right-sided hearing impairment with tinnitus. She underwent electrocochleography (ECochG) and examination of evoked otoacoustic emissions (EOAEs) to assess cochlear function. An acoustic probe to measure EOAEs was inserted into the external ear canal. The ECochG action potential and cochlear microphonics were recorded by a transtympanic needle electrode technique. Both fast and slow components of EOAEs appeared in either the period of deteriorated hearing acuity or when it was improved. They showed normal detection thresholds and input-output curves during both periods. Cochlear microphonics with almost normal detection thresholds and input-output functions were obtained during the period of deteriorated hearing acuity. Action potential (N1) input-output curves during relapse with hearing loss were notably lower in amplitude and longer in latency than those obtained at the time hearing impairment showed improvement. The EOAE and ECochG findings suggested that this patient had almost normal cochlear function, and we assumed from the magnetic resonance imaging and auditory brain stem response findings as well as the ECochG that the hearing impairment was caused by dysfunction of auditory pathways in the brain stem, including structures that contribute to generation of the N1 potential of the ECochG.