Electrocochleographic frequency-following responses as a potential marker of age-related cochlear neural degeneration.

Auditory nerve (AN) fibers that innervate inner hair cells in the cochlea degenerate with advancing age. It has been proposed that age-related reductions in brainstem frequency-following responses (FFR) to the carrier of low-frequency, high-intensity pure tones may partially reflect this neural loss in the cochlea (Märcher-Rørsted et al., 2022). If the loss of AN fibers is the primary factor contributing to age-related changes in the brainstem FFR, then the FFR could serve as an indicator of cochlear neural degeneration. In this study, we employed electrocochleography (ECochG) to investigate the effects of age on frequency-following neurophonic potentials, i.e., neural responses phase-locked to the carrier frequency of the tone stimulus. We compared these findings to the brainstem-generated FFRs obtained simultaneously using the same stimulation. We conducted recordings in young and older individuals with normal hearing. Responses to pure tones (250 ms, 516 and 1086 Hz, 85 dB SPL) and clicks were recorded using both ECochG at the tympanic membrane and traditional scalp electroencephalographic (EEG) recordings of the FFR. Distortion product otoacoustic emissions (DPOAE) were also collected. In the ECochG recordings, sustained AN neurophonic (ANN) responses to tonal stimulation, as well as the click-evoked compound action potential (CAP) of the AN, were significantly reduced in the older listeners compared to young controls, despite normal audiometric thresholds. In the EEG recordings, brainstem FFRs to the same tone stimulation were also diminished in the older participants. Unlike the reduced AN CAP response, the transient-evoked wave-V remained unaffected. These findings could indicate that a decreased number of AN fibers contributes to the response in the older participants. The results suggest that the scalp-recorded FFR, as opposed to the clinical standard wave-V of the auditory brainstem response, may serve as a more reliable indicator of age-related cochlear neural degeneration.

Simultaneous Contralateral Vestibular Schwannoma and Glomus Tumor of the Temporal Bone- A Case Report.

INTRODUCTION: Presence of vestibular schwannoma and a simultaneous glomus jugulare tumor is an extremely rare event. There is only one case report regarding the incidence of a contralateral vestibular schwannoma, along with a glomus jugulare tumor. Herein, we present the second case with a contralateral tumor. CASE REPORT: A 69-year-old woman presented with a long history of bilateral hearing loss and a 2-year history of left-sided pulsatile tinnitus. The patient also suffered the itching of the left ear canal and mild vertigo; however, she had no recollection of middle ear infection, ear discharge, or ear pain. Magnetic resonance imaging (MRI) revealed a right-sided 8-mm extrameatal vestibular schwannoma and a left-sided almost purely extracranial glomus jugulare tumor of 18 mm. The pure-tone average values were 63 and 43 dB HL for the right and left ears, respectively. Speech audiometry showed a discrimination score of 76/88 (%). Caloric irrigation was performed and revealed a unilateral weakness of 81% towards the side of vestibular schwannoma. The patient was included in a watchful waiting regimen with annual MRI scans. CONCLUSION: Though vestibular schwannomas and glomus jugulare tumors are pathophysiologically different, they are similar in terms of symptomatology, growth pattern, diagnostic process, and therapeutic strategy. Based on this case report, it can be concluded that a vestibular evaluation demonstrates a unilateral vestibular weakness towards the side of the vestibular schwannoma, thereby facilitating clinical discrimination between the lesions.

Squamous cell carcinoma of the nasal vestibule 1993-2002: a nationwide retrospective study from DAHANCA.

BACKGROUND: A retrospective nationwide study of cancer of the nasal vestibule was conducted to evaluate classification systems and prognostic factors for treatment outcome. METHODS: Patients treated between 1993 and 2002 at head and neck oncology centers in Denmark were included. RESULTS: The 5-year results were locoregional control 67%, overall survival 50%, cancer-specific survival 74%. Cancer-specific survival according to Wang classification was 83%, 63%, and 39% for T1, T2, T3, respectively (p < .000). Regarding T1 tumors, 5-year locoregional control for surgery, surgery + radiotherapy (RT), or RT was 94%, 87%, or 61%, respectively (p < .000). Fifty-four Gray in 18 fractions was found comparable with 66 Gy in 33 fractions regarding T1 tumors. CONCLUSION: This national survey is the largest series of nasal vestibule cancer ever published. Wang classification is more prognostic and easier to use than the Union Internationale Contre le Cancer 2002. Surgery or hypofractionated RT can be used for T1 lesions, whereas larger lesions should be treated with combined approach.