Otolaryngology Training in Uganda: The Mbarara University of Science and Technology Experience.

Sub-Saharan Africa has a high otolaryngologic disease burden exacerbated by an inadequate number of otolaryngologists. The Otolaryngology department at Mbarara University of Science & Technology in Uganda is addressing this problem by having created Uganda's second national residency training program in 2010. We chronicled an early period in the program's development by reporting surgical case quantity and complexity, as defined by "key indicator procedure" classification per the United States Accreditation Council for Graduate Medical Education, and interpreting it with respect to a timeline of significant events. Procedure complexity, but not total number per year, increased over the study period-KIPs increased from 3% in 2012 (6 of 175 total procedures) to 29% in 2016 (35 of 135 total procedures). During this period of complexity increase, operating room capacity expanded, faculty received advanced training and increased in number, and operative equipment improved.

Assessment of Sudden Sensorineural Hearing Loss After COVID-19 Vaccination.

IMPORTANCE: Emerging reports of sudden sensorineural hearing loss (SSNHL) after COVID-19 vaccination within the otolaryngological community and the public have raised concern about a possible association between COVID-19 vaccination and the development of SSNHL. OBJECTIVE: To examine the potential association between COVID-19 vaccination and SSNHL. DESIGN, SETTING, AND PARTICIPANTS: This cross-sectional study and case series involved an up-to-date population-based analysis of 555 incident reports of probable SSNHL in the Centers for Disease Control and Prevention Vaccine Adverse Events Reporting System (VAERS) over the first 7 months of the US vaccination campaign (December 14, 2020, through July 16, 2021). In addition, data from a multi-institutional retrospective case series of 21 patients who developed SSNHL after COVID-19 vaccination were analyzed. The study included all adults experiencing SSNHL within 3 weeks of COVID-19 vaccination who submitted reports to VAERS and consecutive adult patients presenting to 2 tertiary care centers and 1 community practice in the US who were diagnosed with SSNHL within 3 weeks of COVID-19 vaccination. EXPOSURES: Receipt of a COVID-19 vaccine produced by any of the 3 vaccine manufacturers (Pfizer-BioNTech, Moderna, or Janssen/Johnson & Johnson) used in the US. MAIN OUTCOMES AND MEASURES: Incidence of reports of SSNHL after COVID-19 vaccination recorded in VAERS and clinical characteristics of adult patients presenting with SSNHL after COVID-19 vaccination. RESULTS: A total of 555 incident reports in VAERS (mean patient age, 54 years [range, 15-93 years]; 305 women [55.0%]; data on race and ethnicity not available in VAERS) met the definition of probable SSNHL (mean time to onset, 6 days [range, 0-21 days]) over the period investigated, representing an annualized incidence estimate of 0.6 to 28.0 cases of SSNHL per 100 000 people per year. The rate of incident reports of SSNHL was similar across all 3 vaccine manufacturers (0.16 cases per 100 000 doses for both Pfizer-BioNTech and Moderna vaccines, and 0.22 cases per 100 000 doses for Janssen/Johnson & Johnson vaccine). The case series included 21 patients (mean age, 61 years [range, 23-92 years]; 13 women [61.9%]) with SSNHL, with a mean time to onset of 6 days (range, 0-15 days). Patients were heterogeneous with respect to clinical and demographic characteristics. Preexisting autoimmune disease was present in 6 patients (28.6%). Of the 14 patients with posttreatment audiometric data, 8 (57.1%) experienced improvement after receiving treatment. One patient experienced SSNHL 14 days after receiving each dose of the Pfizer-BioNTech vaccine. CONCLUSIONS AND RELEVANCE: In this cross-sectional study, findings from an updated analysis of VAERS data and a case series of patients who experienced SSNHL after COVID-19 vaccination did not suggest an association between COVID-19 vaccination and an increased incidence of hearing loss compared with the expected incidence in the general population.

Is Serial Electroneuronography Indicated Following Temporal Bone Trauma?

OBJECTIVE: Contemporary guidelines advise facial nerve (FN) decompression within 2 weeks of temporal bone trauma if a single electroneuronography (ENoG) demonstrates more than 90% degeneration of the FN. We report a case series demonstrating the potential of serial ENoG to guide FN management more than 2 weeks following injury. PATIENTS: Adults with traumatic temporal bone fractures and resultant ipsilateral FN paresis. INTERVENTION: Serial ENoG followed by observation or decompression of the FN. MAIN OUTCOME MEASURE: House-Brackmann (HB) graded FN function. RESULTS: Nine cases of blunt temporal bone trauma resulting in ispilateral FN paralysis were identified and reviewed. Two patients were women, and average age at the time of trauma was 30 years (range, 17-52). Immediate paralysis occurred in four cases, while five were delayed. A single ENoG was performed in seven patients and was predictive of final function in six, while one patient had an initially reassuring ENoG but did not obtain full recovery of FN function (HB 4). Two patients underwent serial ENoG on a weekly basis which, while initially reassuring, demonstrated declining FN function on subsequent testing. Decompression was performed in both patients with excellent recovery of FN function (HB1 and HB2). CONCLUSIONS: The majority of ENoGs performed within 2 weeks of temporal bone trauma provide sufficient prognostic data for treatment decisions; however, in selected cases, a single ENoG may not adequately predict long-term FN outcomes. For patients failing to improve with observation alone, serial ENoG may capture declining FN function, identifying patients that may benefit from late decompression.

The Audiometric and Mechanical Effects of Partial Ossicular Discontinuity.

OBJECTIVES: Ossicular discontinuity may be complete, with no contact between the disconnected ends, or partial, where normal contact at an ossicular joint or along a continuous bony segment of an ossicle is replaced by soft tissue or simply by contact of opposing bones. Complete ossicular discontinuity typically results in an audiometric pattern of a large, flat conductive hearing loss. In contrast, in cases where otomicroscopy reveals a normal external ear canal and tympanic membrane, high-frequency conductive hearing loss has been proposed as an indicator of partial ossicular discontinuity. Nevertheless, the diagnostic utility of high-frequency conductive hearing loss has been limited due to gaps in previous research on the subject, and clinicians often assume that an audiogram showing high-frequency conductive hearing loss is flawed. This study aims to improve the diagnostic utility of high-frequency conductive hearing loss in cases of partial ossicular discontinuity by (1) making use of a control population against which to compare the audiometry of partial ossicular discontinuity patients and (2) examining the correlation between high-frequency conductive hearing loss and partial ossicular discontinuity under controlled experimental conditions on fresh cadaveric temporal bones. Furthermore, ear-canal measurements of umbo velocity and wideband acoustic immittance measurements were investigated to determine the usefulness regarding diagnosis of ossicular discontinuity. DESIGN: The authors analyzed audiograms from 66 patients with either form of surgically confirmed ossicular discontinuity and no confounding pathologies. The authors also analyzed umbo velocity (n = 29) and power reflectance (n = 12) measurements from a subset of these patients. Finally, the authors performed experiments on six fresh temporal bone specimens to study the differing mechanical effects of complete and partial discontinuity. The mechanical effects of these lesions were assessed via laser Doppler measurements of stapes velocity. In a subset of the specimen (n = 4), wideband acoustic immittance measurements were also collected. RESULTS: (1) Calculations comparing the air-bone gap (ABG) at high and low frequencies show that when high-frequency ABGs are larger than low-frequency ABGs, the surgeon usually reported soft-tissue bands at the point of discontinuity. However, in cases with larger low-frequency ABGs and flat ABGs across frequencies, some partial discontinuities as well as complete discontinuities were reported. (2) Analysis of umbo velocity and power reflectance (calculated from wideband acoustic immittance) in patients reveal no significant difference across frequencies between the two types of ossicular discontinuities. (3) Temporal bone experiments reveal that partial discontinuity results in a greater loss in stapes velocity at high frequencies when compared with low frequencies, whereas with complete discontinuity, large losses in stapes velocity occur at all frequencies. CONCLUSION: The clinical and experimental findings suggest that when encountering larger ABGs at high frequencies when compared with low frequencies, partial ossicular discontinuity should be considered in the differential diagnosis.

Stapediovestibular dislocation depicted on temporal bone computed tomography with 3D rendering.

Stapediovestibular dislocation is an unusual form of ossicular trauma. In this article, a case of medial stapediovestibular dislocation and pneumolabyrinth due to penetrating injury with a stick diagnosed on temporal bone CT is described. In particular, 3D CT renderings can aid in the evaluation of the displaced ossicles.

Malignant transformation of a highly aggressive human papillomavirus type 11-associated recurrent respiratory papillomatosis.

OBJECTIVE: The objective is to present an uncommon case of squamous cell carcinoma (SCC) arising from extensive recurrent respiratory papillomatosis (RRP) involving the upper and lower airway and temporal bone. STUDY DESIGN: This is a case report and a review of the literature. METHODS: We describe a case of a 24-year-old woman with a history of human papillomavirus (HPV) type 11 since childhood originating in the larynx and trachea, then progressing to involve the distal pulmonary alveoli and right middle ear through the eustachian tube. Papillomatous growth was treated with multiple surgeries including laser cytoreduction of laryngotracheal papillomatosis and radical mastoidectomy, followed by a trial of chemotherapy. Despite this aggressive treatment regimen, papillomatous growth progressed with recurrence in the right eustachian tube, middle ear, and mastoid eventually extending to involve the calvaria and scalp. RESULTS: The patient underwent a composite resection of involved tissues, including the scalp, auricle, and lateral temporal bone, with reconstruction using a latissimus dorsi free flap. Final pathologic analysis revealed an extensive infiltrative well-differentiated SCC arising from the papilloma. A review of the literature on aggressive respiratory papillomatosis suggests that malignant transformation of juvenile-onset RRP occurs exclusively in cases positive for HPV-11. CONCLUSIONS: We report an unusual case of SCC originating from extensive RRP involving the airway, temporal bone, and scalp and describe the medical and surgical management. Although the incidence of juvenile-onset RRP transformation to SCC is very low, the presence of HPV-11 as a risk factor for malignant transformation of RRP is becoming evident.

Central auditory pathways mediating the rat middle ear muscle reflexes.

The middle ear muscle (MEM) reflexes function to protect the inner ear from intense acoustic stimuli and to reduce acoustic masking. Sound presented to the same side or to the opposite side activates the MEM reflex on both sides. The ascending limbs of these pathways must be the auditory nerve fibers originating in the cochlea and terminating in the cochlear nucleus, the first relay station for all ascending auditory information. The descending limbs project from the motoneurons in the brainstem to the MEMs on both sides, causing their contraction. Although the ascending and descending pathways are well described, the cochlear nucleus interneurons that mediate these reflex pathways have not been identified. In order to localize the MEM reflex interneurons, we developed a physiologically based reflex assay in the rat that can be used to determine the integrity of the reflex pathways after experimental manipulations. This assay monitored the change in tone levels and distortion product otoacoustic emissions within the ear canal in one ear during the presentation of a reflex-eliciting sound stimulus in the contralateral ear. Preliminary findings using surgical transection and focal lesioning of the auditory brainstem to interrupt the MEM reflexes suggest that MEM reflex interneurons are located in the ventral cochlear nucleus.

Medial olivocochlear reflex interneurons are located in the posteroventral cochlear nucleus: a kainic acid lesion study in guinea pigs.

The medial olivocochlear (MOC) reflex arc is probably a three-neuron pathway consisting of type I spiral ganglion neurons, reflex interneurons in the cochlear nucleus, and MOC neurons that project to the outer hair cells of the cochlea. We investigated the identity of MOC reflex interneurons in the cochlear nucleus by assaying their regional distribution using focal injections of kainic acid. Our reflex metric was the amount of change in the distortion product otoacoustic emission (at 2f(1)-f(2)) just after onset of the primary tones. This metric for MOC reflex strength has been shown to depend on an intact reflex pathway. Lesions involving the posteroventral cochlear nucleus (PVCN), but not the other subdivisions, produced long-term decreases in MOC reflex strength. The degree of cell loss within the dorsal part of the PVCN was a predictor of whether the lesion affected MOC reflex strength. We suggest that multipolar cells within the PVCN have the distribution and response characteristics appropriate to be the MOC reflex interneurons.