Trans-mastoid plugging of superior semicircular canal dehiscence: long-term follow-up.

OBJECTIVE: To evaluate the long-term outcomes of trans-mastoid plugging of superior semicircular canal dehiscence (SSCD), focusing on complicated cases. METHODS: In this cohort study, we included all patients who underwent trans-mastoid plugging of SSCD between 2009 and 2019. We evaluated the symptoms (autophony, sound-/pressure-induced vertigo, disequilibrium, aural fullness and pulsatile tinnitus) before and 1 year after surgery in the medical records. We systematically assessed the current symptoms 6.2 ± 3 years postoperative (range 2.2-12.3 years) using questionnaires sent by post and validated by telephone interviews. We also documented any complications and the need for further procedures. We compared pure tone and speech audiometry before and 1 year after surgery. Finally, the degree of mastoid pneumatisation and mastoid tegmen anatomy were reviewed on preoperative CT scans. RESULTS: We included 24 ears in 23 patients. No complications were recorded, and none required a second procedure for SSCD. Following surgery, oscillopsia and Tullio phenomena resolved in all patients. Hyperacusis, autophony, and aural fullness were also settled in all patients except one. Balance impairment persisted to some degree in 35% of patients. No deterioration over the years was reported regarding the above symptoms. On average, bone conduction pure tone average pre- and 1 year postoperative were 13.7 ± 17 and 20.5 ± 18 dB, respectively (P = 0.002). Air bone gaps were reduced from 12.7 ± 8 to 5.9 ± 6 (P = 0.001). Two patients had a significant sclerotic mastoid, three had a prominent low-lying mastoid tegmen, and two had both. Anatomy had no effect on outcome. CONCLUSION: Trans-mastoid plugging of SSCD is a reliable and effective technique which achieves long-lasting symptom control, even in cases with sclerotic mastoid or low-lying mastoid tegmen.

Cochlear microphonic latency predicts outer hair cell function in animal models and clinical populations.

As recently reported, electrocochleography recorded in cochlear implant recipients showed reduced amplitude and shorter latency in patients with more severe high-frequency hearing loss compared with those with some residual hearing. As the response is generated primarily by receptor currents in outer hair cells, these variations in amplitude and latency may indicate outer hair cell function after cochlear implantation. We propose that an absence of latency shift when the cochlear microphonic is measured on two adjacent electrodes indicates an absence or dysfunction of outer hair cells between these electrodes. We test this preclinically in noise deafened guinea pigs (2 h of a 124 dB HL, 16-24 kHz narrow-band noise), and clinically, in electrocochleographic recordings made in cochlear implant recipients immediately after implantation. We found that normal hearing guinea pigs showed a progressive increase in latency from basal to apical electrodes. In contrast, guinea pigs with significantly elevated high-frequency hearing thresholds showed no change in cochlear microphonic latency measured on basal electrodes (located approximately at the 16-24 kHz location in the cochlea).. In the clinical cohort, a significant negative correlation existed between cochlear microphonic latency shifts and hearing thresholds at 1-, 2-, & 4 kHz when tested on electrodes located at the relevant cochlear tonotopic place. This reduction in latency shift was such that patients with no measurable hearing also had no detectable latency shift (place assessed by CT scan, r's of -.70 to -.83). These findings suggest that electrocochleography can be used as a diagnostic tool to detect cochlear regions with functioning hair cells, which may be important for defining cross-over point for electro-acoustic stimulation.

Primary basal cell carcinoma of the prostate with concurrent adenocarcinoma.

INTRODUCTION: Prostatic basal cell carcinoma is an extremely rare tumor, exhibiting various histopathological features and clinical spectrums of disease. CASE PRESENTATION: A 69-year-old male presented to our department with 2 years of voiding difficulty and intermittent macroscopic hematuria. With a presumed diagnosis of benign prostatic hyperplasia, he underwent a transurethral resection of the prostate. Pathological examination revealed atypical basaloid cells forming solid nests. Robot-assisted radical prostatectomy was subsequently performed, confirming a diagnosis of basal cell carcinoma with coexisting acinar adenocarcinoma. CONCLUSION: Although more cases of basal cell carcinoma are indolent than aggressive, there is no reliable method of differentiation between these presentations. Thus, we recommend radical surgery and 6-monthly disease surveillance until more is discovered about this very rare malignancy.

Electrophysiological Evidence of the Basilar-Membrane Travelling Wave and Frequency Place Coding of Sound in Cochlear Implant Recipients.

AIM: To obtain direct evidence for the cochlear travelling wave in humans by performing electrocochleography from within the cochlea in subjects implanted with an auditory prosthesis. BACKGROUND: Sound induces a travelling wave that propagates along the basilar membrane, exhibiting cochleotopic tuning with a frequency-dependent phase delay. To date, evoked potentials and psychophysical experiments have supported the presence of the travelling wave in humans, but direct measurements have not been made. METHODS: Electrical potentials in response to rarefaction and condensation acoustic tone bursts were recorded from multiple sites along the human cochlea, directly from a cochlear implant electrode during, and immediately after, its insertion. These recordings were made from individuals with residual hearing. RESULTS: Electrocochleography was recorded from 11 intracochlear electrodes in 7 ears from 6 subjects, with detectable responses on all electrodes in 5 ears. Cochleotopic tuning and frequency-dependent phase delay of the cochlear microphonic were demonstrated. The response latencies were slightly shorter than those anticipated which we attribute to the subjects' hearing loss. CONCLUSIONS: Direct evidence for the travelling wave was observed. Electrocochleography from cochlear implant electrodes provides site-specific information on hair cell and neural function of the cochlea with potential diagnostic value.

Characterizing Electrocochleography in Cochlear Implant Recipients with Residual Low-Frequency Hearing.

Objective: Lay the groundwork for using electrocochleography (ECochG) as a measure of cochlear health, by characterizing typical patterns of the ECochG response observed across the electrode array in cochlear implant recipients with residual hearing. Methods: ECochG was measured immediately after electrode insertion in 45 cochlear implant recipients with residual hearing. The Cochlear Response Telemetry system was used to record ECochG across the electrode array, in response to 100- or 110-dB SPL pure tones at 0.5-kHz, presented at 14 per second and with alternating polarities. Hair cell activity, as the cochlear microphonic (CM), was estimated by taking the difference (DIF) of the two polarities. Neural activity, as the auditory nerve neurophonic (ANN), was estimated by taking the sum (SUM) of the two polarities. Prior work in humans and animal studies suggested that the expected ECochG pattern in response to a 0.5-kHz pure tone is an apical-peak in CM amplitude and latency. Results: The most prevalent pattern was a peak in the DIF amplitude near the most apical electrode, with a prolongation of latency toward the electrode tip; this was found in 21/39 individuals with successful ECochG recordings. The 21 apical-peak recipients had the best low-frequency hearing. A low amplitude, long-latency DIF response that remained relatively constant across the electrode array was found in 10/39 individuals, in a group with the poorest low- and high-frequency hearing. A third, previously undescribed, pattern occurred in 8/39 participants, with mid-electrode peaks in DIF amplitude. These recipients had the best high-frequency hearing and a progressive prolongation of DIF latency around the mid-electrode peaks consistent with the presence of discrete populations of hair cells. Conclusions: The presence of distinct patterns of the ECochG response with relationships to pre-operative hearing levels supports the notion that ECochG across the electrode array functions as a measure of cochlear health.

Sites of origin of oral cavity cancer in nonsmokers vs smokers: possible evidence of dental trauma carcinogenesis and its importance compared with human papillomavirus.

IMPORTANCE: The relatively high and possibly rising incidence of mouth squamous cell carcinoma in nonsmokers, especially women, without obvious cause has been noted by previous authors. Is chronic dental trauma and irritation a carcinogen, and what is its importance compared with human papillomavirus (HPV) oropharyngeal cancer in nonsmokers? OBJECTIVE: To determine whether oral cavity cancers occurred more commonly at sites of dental trauma and how the position of these cancers varied between nonsmokers lacking major identified carcinogens and smokers. If these cancers occurred more frequently at sites of chronic trauma, especially in nonsmokers, it would suggest chronic dental trauma as a possible carcinogen. DESIGN, SETTING, AND PARTICIPANTS: A retrospective analysis of 881 patients with oral cavity or oropharyngeal cancers seen through a tertiary referral hospital between 2001 and 2011 was performed. MAIN OUTCOMES AND MEASURES: Patient medical records were analyzed to determine the location of the tumor within the oral cavity and oropharynx and how it relates to patient demographics, smoking and alcohol histories, and comorbidities. Dental histories were also sought, including use of dentures. RESULTS: Nonsmokers comprised 87 of 390 patients with mouth cancer (22%) and 48 of 334 patients with oropharyngeal cancer (14%). Female nonsmoking patients included 53 with oral cancer (61%) but only 12 with oropharyngeal squamous cell carcinoma (25%). Oral cancers occurred on the lateral tongue, a potential site of chronic dental trauma, in 57 nonsmokers (66%) compared with 107 smokers/ex-smokers (33%) (P < .001). Gingival and floor of mouth lesions occurred in older patients, possibly from chronic denture rubbing. Twenty-six patients had dental abnormalities recorded in close proximity to where their tumor developed. CONCLUSIONS AND RELEVANCE: Oral cavity cancers occur predominantly at sites of potential dental and denture trauma, especially in nonsmokers without other risk factors. Recognizing teeth irritation as a potential carcinogen would have an impact on prevention and treatment strategies.