Utility of otoacoustic emissions and olivocochlear reflex in predicting vulnerability to noise-induced inner ear damage

Aim: The aim of the present study was to explore the possible utility of otoacoustic emissions (OAEs) and efferent system strength to determine vulnerability to noise exposure in a clinical setting. Materials and Methods: The study group comprised 344 volunteers who had just begun mandatory basic training as Hellenic Corps Officers Military Academy cadets. Pure-tone audiograms were obtained on both ears. Participants were also subjected to diagnostic transient-evoked otoacoustic emissions (TEOAEs). Finally, they were all tested for efferent function through the suppression of TEOAEs with contralateral noise. Following baseline evaluation, all cadets fired 10 rounds using a 7.62 mm Heckler & Koch G3A3 assault rifle while lying down in prone position. Immediately after exposure to gunfire noise and no later than 10 h, all participants completed an identical protocol for a second time, which was then repeated a third time, 30 days later. Results: The data showed that after the firing drill, 280 participants suffered a temporary threshold shift (TTS) (468 ears), while in the third evaluation conducted 30 days after exposure, 142 of these ears still presented a threshold shift compared to the baseline evaluation [permanent threshold shift (PTS) ears]. A receiver operating characteristics curve analysis showed that OAEs amplitude is predictive of future TTS and PTS. The results were slightly different for the suppression of OAEs showing only a slight trend toward significance. The curves were used to determine cut points to evaluate the likelihood of TTS/PTS for OAEs amplitude in the baseline evaluation. Decision limits yielding 71.6% sensitivity were 12.45 dB SPL with 63.8% specificity for PTS, and 50% sensitivity were 12.35 dB SPL with 68.2% specificity for TTS. Conclusions: Interestingly, the above data yielded tentative evidence to suggest that OAEs amplitude is both sensitive and specific enough to efficiently identify participants who are particularly susceptible to hearing loss caused by impulse noise generated by firearms. Hearing conservation programs may therefore want to consider including such tests in their routine. As far as efferent strength is concerned, we feel that further research is due, before implementing the suppression of OAEs in hearing conservations programs in a similar manner

Ceruminous Adenoma of the External Auditory Canal: A Case Report with Imaging and Pathologic Findings

Ceruminous adenomas are benign tumors that are rare in humans and present with a nonspecific symptomatology. The treatment of choice is surgical excision. We present an 87-year-old woman who presented with a reddish, tender, round, soft mass of the outer third of the inferior wall of the left external auditory canal, discharging a yellowish fluid upon pressure. Coincidentally, due to her poor general condition, this patient also showed symptoms consistent with chronic otitis media, parotitis, and cervical lymphadenopathy, such as otorrhea, through a ruptured tympanic membrane and swelling of the parotid gland and cervical lymph nodes. The external auditory canal lesion was surgically excised under general anesthesia, utilizing a transmeatal approach. The pathological diagnosis was ceruminous gland adenoma. The tumor was made of tubular and cystic structures and embedded in a fibrous, focally hyalinized stroma. Immunohistochemistry confirmed the presence of two distinct cell populations. The luminal cells expressed keratin 7, while peripheral (basal) cells expressed keratins 5/6, S100 protein, and p63. The apocrine gland-related antigen GCDFP-15 was focally expressed by tumor cells. The postoperative course was uneventful and at the 2-year follow-up no recurrence of the ceruminous adenoma was noted

Duplication of the External Auditory Canal: Two Cases and a Review of the Literature

The objective of the present paper is to describe the clinical presentation, diagnostic process, surgical treatment, and outcome of 2 patients with first branchial cleft anomaly. The first case was an 8-year-old girl presented with an elastic lesion located in the left infra-auricular area, in close relation with the lobule, duplicating the external auditory canal. The magnetic resonance imaging revealed a lesion, appearing as a rather well-circumscribed mass within the left parotid gland and duplicating the ear canal. A superficial parotidectomy was subsequently performed, with total excision of the cyst. The second patient was a 15-year-old girl presented with a congenital fistula of the right lateral neck. At superficial parotidectomy, a total excision of the fistula was performed. During the operation the tract was recorded to lay between the branches of the facial nerve, extending with a blind ending canal parallel to the external acoustic meatus. Conclusively, first branchial cleft anomalies are rare malformations with cervical, parotid, or auricular clinical manifestations. Diagnosis of first branchial cleft lesions is achieved mainly through careful physical examination. Complete surgical excision with wide exposure of the lesion is essential in order to achieve permanent cure and avoid recurrence