Search

Cubic difference tone (CDT) otoacoustic emissions are thought to arise from the feedback loop allowing outer hair cells to enhance the sensitivity and tuning of the organ of Corti. The existence of residual CDTs during complete cochlear ischemia is therefore disturbing. That stimulus intensities must exceed 50-60 dB SPL for residual CDTs to be recorded and for level notches to be present in CDT growth functions is often cited as evidence for a two-component, "active/passive" model: one component, the residual one, would originate from a passive, hardly vulnerable mechanism and thus be unsuitable for hearing screening purposes. This model was probed in gerbil ears after complete interruption of the cochlear blood flow. Cochlear potentials and CDTs were controlled simultaneously through continuous monitoring of CDT level and phase for 50 and 60 dB SPL stimuli and group-delay measurements. After a clear initial decay, CDT levels elicited at 60 dB SPL plateaued for several minutes at about 20 dB below initial level, and when early level notches were observed, CDT phase changes remained minor. The CDT group delays decreased by less than 30%. Later CDT level notches were associated with sharp phase reversals but the similarity between CDT characteristics before and after a notch was hardly consistent with a two-component interpretation. When mild sound overexposure (pure tone, 90-95 dB SPL, 15-30 min) had been performed prior to ischemia, little or no ischemic CDT came from the frequency bands where auditory fatigue had been detected (within 1 kHz), irrespective of the stimulus intensity. It suggests that instead of being passive, residual ischemic CDTs were vulnerable and produced according to a near-normal tonotopy by the same mechanisms that were sensitive to auditory fatigue. All the results lined up with a simple feedback model of cochlear function assuming a single CDT source related to mechano-electrical transduction in outer hair cells. More parsimonious than a two-component model, it posits that although early stages of ischemia dramatically impair the overall performance of the cochlea, the nonlinear mechanical stages responsible for the existence of CDTs keep working albeit at higher intensities.

Guinea pigs were exposed to a pure tone at 6 kHz and 80 dB SPL for 30 minutes in order to induce mild reversible auditory fatigue over the 4 hours following exposure. Cochlear monitoring aimed to compare the shifts in round-window compound action potentials (CAP) thresholds to those of 2f1-f2 distortion-product otoacoustic emissions (DPOAE, frequency of stimuli f1 and f2). Both responses were evaluated every 1/10th octave between 6 and 12 kHz for CAP thresholds, and from 4 to about 14 kHz for DPOAEs in response to 50- and 70-dB SPL stimuli. The auditory fatigue turned out to be sufficiently mild that DPOAEs remained present, so that their microstructure could be followed up while the stimulus frequency ratio f2/f1 was swept from 1.06 to 1.30 (fixed f2) so as to derive DPOAE level profiles against f2/f1 and group latencies. CAP thresholds decreased by about 10 dB above 7.2 kHz, whereas DPOAE amplitudes decreased at most f2 frequencies from 6.6 kHz to 15.2 kHz, with the range of decrease being slightly narrower at higher stimulus intensities. While the mean DPOAE shift after 1 hour was around 5 dB irrespective of stimulus intensity, it tended to increase slightly after 2 hours despite stable CAP thresholds. DPOAE profiles against f2/f1 were slightly modified by the auditory fatigue, so that the maximum tended to be reached at lower ratio. No significant variation of DPOAE latencies was found after acoustic overstimulation. These experiments show that complex DPOAE changes were induced by auditory fatigue and their relationship to CAP threshold changes does not seem to be straight-forward. Nonetheless, fine DPOAE recordings might be useful to detect early changes in cochlear mechanics.

Objectives: We sought to prevent postoperative swallowing disorder, aspiration, and sputum retention in cases of recurrent laryngeal or vagus nerve section occurring during lung cancer resection., Methods: In 14 of 25 consecutive patients, type I thyroplasty and thoracic operations were performed during the same period of anesthesia. All patients had a preoperative laryngeal computed tomographic scan providing us with indispensable measurements for vocal fold medialization under general anesthesia (ie, without intraoperative phonatory control). Nine remaining patients had a type I thyroplasty delayed from thoracic operations because of intraoperative doubt about laryngeal innervation injury, and 2 did not need a laryngeal operation. Main postoperative records consisted of swallowing ability, respiratory complications, and quality of voice., Results: No swallowing disorder, aspiration, or sputum retention occurred in cases of concomitant laryngeal and thoracic operations. Of these 14 patients, a single case (7%) of major complication (vocal fold overmedialization) occurred and required an early and successful revision thyroplasty; one case of cervical hematoma that did not require surgical drainage was considered a minor complication (7%). Twelve (86%) patients who underwent the concomitant association of both operations were fully satisfied with their quality of voice., Conclusions: Type I thyroplasty and thoracic operation can be advantageously associated in case of injury to laryngeal motor innervation to prevent postoperative swallowing disability and dramatic respiratory complications.

Distortion product otoacoustic emissions (DPOAE) are increasingly used as an objective test for noninvasive hearing screening. When two pure tones with frequencies f1 and f2 are sent to the cochlea, the most prominent DPOAE is the cubic one produced at 2f1-f2, and this presentation will mainly emphasize its properties. DPOAEs are undoubtedly generated by cochlear nonlinearities. It is widely held that they arise from certain stages of sound processing by the outer hair cells (OHC) and that OHCs ensure normal cochlear sensitivity and tuning. Thus, DPOAEs should provide a privileged tool for monitoring the harmful effects of loud sound because OHCs are known to be one of the main targets of NIHL. Although DPOAEs provide the clinicians with a reliable screening limit of about 30 dB HL around f2, no reliable relationship has been found thus far between possible residual DPOAEs and either hearing loss or amount of impaired sensory cells. Furthermore, puzzling contradictory findings have been reported as to the presence of DPOAEs despite a large hearing loss (i.e. >30-40 dB) notably with high-level stimuli. These observations raise the following issues. What is the generation site of DPOAEs in a normal or pathological cochlea (OHCs, basilar membrane, place tuned to f2, 2f1-f2, places basal to f2.)? Is it necessary to account for interferences between several discrete sources, arising from different locations or different mechanisms and possibly exhibiting differential susceptibility to sensory cell damage? Do DPOAE changes depend on the nature of OHC pathology (NIHL, anoxia, ototoxic drugs, genetics.)? Once a source of DPOAE is characterized, is there any means of modelling the physiological process of its generation and deriving what might quantitatively relate DPOAE amount to sensory cell activity and thresholds? The goal of this presentation is to examine these issues, review the available data and propose a comparatively simple model.

The spectral quasi-periodicity of transient-evoked otoacoustic emissions (TEOAE) is well acknowledged since Zwicker described a preferred spacing of 0.4 bark between consecutive peaks in the spectrum of otoacoustic emissions from normal ears. While there is scarce evidence of any anatomical reason for this regularity, several functional models of the cochlea have predicted that the structure of emission spectra reflects important characteristics of cochlear filters. In an attempt to check such predictions, the average regularity of TEOAE spectra was studied in three groups of human subjects, normally hearing adults, healthy neonates, and adults suffering from noise-induced hearing loss. Significant differences in emission periodicities were found. Around 1 kHz, the preferred spacing was close to 130 Hz in normally hearing adult ears and neonates. In contrast, no clear periodicity was found in the group of damaged ears, even though they had clinically normal pure-tone audiometry below 2 kHz. Around 4 kHz, the preferred spacing was close to 240 Hz in normal adults and neonates, whereas TEOAEs were absent in many impaired ears. A phenomenological model assuming that TEOAEs stem from the responses of a slightly disarrayed bank of highly tuned filters predicts that the filter width would be the same in healthy young adults and neonates. In contrast, ears suffering from high-frequency hearing loss could exhibit early damaged filters. The proposed method might provide an objective assessment of parameters otherwise difficult to evaluate, especially in neonatal cochleas.

Background: Cochlear ischemia is likely involved in sensorineural hearing loss after cerebellopontine angle (CPA) surgery., Objective: To demonstrate the type of vascular damage to the cochlea, apart from arterial section, that can be induced by CPA surgery., Methods: The effects on measures of both cochlear blood flow (CBF) and distortion-product otoacoustic emissions (DPOAEs) of partial or total mechanical compressions of the internal auditory artery (IAA) were compared in young adult rabbits., Results: When preocclusion baseline activity was compared with postocclusion CBF and DPOAEs, it was clear in the majority of cases that total compressions lasting < or =7 minutes produced the same full recoveries for both measures as did the shorter obstructions of only a few minutes. By contrast, both short and long partial occlusions in which ischemia was interrupted by periods of poor reperfusion (<50% of the initial CBF value) resulted in delayed and prolonged recoveries. In addition, at times, full recovery was not achieved, particularly for DPOAEs, because of vasospasm-like activity., Conclusion: Vasospasm of the IAA was induced by a systematic series of IAA compressions and releases that did not provide for full reperfusion. These data support the concept that vasospasm should be prevented whenever hearing preservation is attempted in CPA surgery.

Unlabelled: The aim of this study was to test the hypothesis that optimism is a predictor of quality of life (QOL) in a sample of upper aerodigestive tract (UADT) cancer patients., Materials and Methods: Consenting patients with squamous cell carcinoma of the UADT were included during the week following disclosure of the diagnosis of their illness, and before the start of treatment. QOL and optimism were evaluated by questionnaires presented to the patients before the start of treatment, after the treatment, and 6 and 12 months after the end of the treatment., Preliminary Results: 92 patients were included. The average age was 58.7+/-11.4 years. Their QOL scores were significantly correlated, first with age (r =- 0.23, p =0.03) and second with degree of optimism (r =0.32, p =0.002). No correlation was found between QOL scores, degree of optimism, and sociodemographic and clinical data. Optimism was the sole variable significantly associated with QOL before treatment (F =4.1, p =0.002, r(2) =0.19). The difference between QOL scores before and after treatment was not significant., Conclusion: Continuation of the study and analysis of survival of the patients may help pinpoint new prognostic factors, both objective and subjective, that will facilitate an overall approach to patient care by allowing for their preferences.

Unlabelled: Adhesion molecules, such as intercellular adhesion molecule-1 (ICAM-1), play an important role in the development of the inflammatory allergic response in the nose. ICAM-1 expression on nasal epithelial cells during allergic reaction is regarded as a major hallmark of allergic inflammation., Objective: The aim of the study was to evaluate the levels of soluble ICAM-1 (sICAM-1) in nasal epithelial lining fluid (ELF) in patients with allergic rhinitis., Patients: Seventeen patients with perennial allergic rhinitis (age: 34,6 +/- 14,6) were screened and the results were compared with those from 11 seasonal allergic rhinitis patients (age: 25.9 +/- 7.4) and 10 non-allergic patients., Methods: The study was performed outside the pollen season. The scores of subjective symptoms were estimated by two differents methods. First, on the basis of a visual analog scale for the symptoms including nasal obstruction, rhinorrhea, sneezing and pruritus. This score was called "Autoscore" (fullmark =40 points). Second, on the basis of a four mark scale for each symptom defined (0 =no symptom, 1 =mild, 2 =moderate, 3 =severe). This score was called "Heteroscore" (fullmark =12 points). Specimens of nasal mucosa were collected by brushing the surface of nasal cavity. Levels of sICAM-1 and sECP (soluble Eosinophilic cationic protein) were measured by specific enzyme-linked immunosorbent assay., Results: The levels of sICAM-1 in ELF were significantly higher (p <0.01) in patients with perennial rhinitis compared to patients with seasonal rhinitis outside the pollen season and to non allergic patients. Levels of sICAM-1 in patients with perennial allergic rhinitis were correlated with levels of sECP (p <0.003) and with the four mark scale scores (p <0. 03) but did not correlate with the visual analog scale scores., Conclusions: sICAM-1 increased in nasal secretions during natural perennial rhinitis and could be considered as a representative hallmark for clinical severity and follow-up evaluation in perennial allergic rhinitis.

An in vivo model in the Mongolian gerbil is used to assess the auditory changes during reversible cochlear ischemia. This model allows the recordings of cochlear potentials (microphonics, summating potential and compound action potential) and otoacoustic emissions (cubic difference tones, CDTs), together with laser Doppler cochlear blood flow (CBF) measurements, over reversible cochlear ischemia. Ischemia is achieved by compression of the eighth nerve complex at the porus of the internal acoustical meatus, whereas the compression release allows the reperfusion to occur. While CBF monitoring permits to objectively determine the degree of ischemia and reperfusion, the combined analysis of cochlear potentials and CDTs makes it possible to point out the preferential site of main functional damage within the cochlea, i.e., outer hair cells (OHCs), inner hair cells, or ganglia cells. At least three ischemia-reperfusion sequences can be used on one side, and sometimes both ears can serve for experiments. This model could be applicable for testing drugs with alleged protective effects against cochlear ischemia and/or reperfusion, in treated vs. non-treated animals.

Acute postoperative pain has seldom been assessed in head and neck cancer surgery. The estimation of actual pain is more difficult when communication is impaired by tracheotomy or tracheostomia. The aim of the present prospective study was the assessment of analgesia level during the first 48 postoperative hours after head and neck cancer surgery. The analgesic procedure involved intra-venous morphine injected by means of a PCA pump (Patient controlled analgesia). Thirty patients were thus treated after cancer surgery of the larynx or the oropharynx. The protocol included during 48 hours the assessment of pain, using a visual analogic scale (VAS) every fourth hour, while recording the total injected dose of morphine, the localisation of pains, as well as the occurrence of side-effects. The control of postoperative pain was shown to be satisfactory, with a VAS grade smaller than 3 at time zero and kept below this value during 48 hours. At the end of this period, the mean total dose of morphine injected was 38 mg. No case of respiratory depression was even seen. It can be concluded that PCA seems to be an efficient procedure for controlling postoperative pain in head and neck cancer surgery. This technique proved to be better than delivering analgesia on requirement.

Objective/hypothesis: Examine and compare in detail the time courses of the auditory brainstem response (ABR) wave I amplitude and latency to the distortion-product otoacoustic emission (DPOAE) amplitude and phase measured in the rabbit model following deliberate obstruction of cochlear blood flow (CBF)., Methods: Using a posterior fossa craniotomy in five rabbits, the internal auditory artery (IAA) was compressed with a probe. ABR and otoacoustic emission were continuously monitored before, during, and after the compressions., Results: ABR wave I amplitudes demonstrated measurable decreases at a mean of 28.3 s after IAA compression, whereas DPOAE amplitudes decreased after a mean of 14.8 s. Wave I latencies began to increase at a mean of 18.3 s after occlusion, while DPOAE phase measures changed after a mean of only 4.8 s following IAA compression. The time-course patterns were similar for the amplitudes of both ABR wave I and DPOAE., Conclusions: ABR wave I amplitude follows a similar, though delayed (by approximately 10 s) time-course pattern to that of the DPOAE following IAA compression. The implication of these findings for intraoperative auditory monitoring is that changes in many currently employed measures will lag actual surgically induced alterations in CBF by at least 20 to 30 s.

Objectives: To assess the intensity of postoperative pain after laryngeal surgery for cancer and the efficacy of analgesic injections at fixed hours., Design: A prospective clinical study performed during the 3 days following laryngeal cancer surgery., Setting: A university medical center., Patients: Fifteen men (age range, 38-74 years) having just undergone a partial or total laryngectomy for epidermoid carcinoma., Interventions: The analgesic treatment consisted of intravenous administrations at fixed hours (propacetamol or nalbuphine hydrochloride), with the possibility of rescue doses on demand. Pain and anxiety were assessed by means of visual analog scales (graduated from 0-10) every 3 hours on postoperative day 1, then every 6 hours on postoperative days 2 and 3. Objective criteria, ie, heart and respiratory rates and mean blood pressure, were measured with the same schedule., Main Outcome Measures: Postoperative pain and anxiety intensities and their variations were analyzed. Correlations between postoperative pain and other criteria were researched., Results: Postoperative pain had a high initial level (maximum median, 7), then decreased and reached a score of 3 at the 30th hour. Unpredictable individual peaks of pain were reported. Anxiety was never high (maximum median, 4). No individual correlation was found between pain and objective parameters., Conclusions: After laryngeal surgery for cancer, pain can reach high levels, particularly in the first hours following recovery. Analgesic administrations at fixed hours are not effective enough. Postoperative analgesic treatment should aim to prevent the high initial pain and be individually adapted.

A 74-year-old man with multiple myeloma developed facial and cervical cellulitis and severe sepsis as a complication of surgery (alar region basal cell carcinoma). The etiological agent was, surprisingly, penicillin-resistant Streptococcus pneumoniae (PRSP). The patient successfully received 16 days of antibiotics. Amoxicillin was given as monotherapy during the last 14 days of treatment. PRSP can be responsible not only for otitis media, pneumonia or meningitis, but also for various other types of infection in patients with predisposing factors.

Unlabelled: Postoperative pain has rarely been assessed after ENT surgery for cancer. Its evaluation is difficult because of the frequent lack of speech after this type of surgery., Objectives: to assess postoperative pain after pharyngeal and laryngeal surgery for cancer., Patients and Method: prospective study in 13 men (38-71 ans) operated on by total laryngectomy with or without partial pharyngectomy. A standardised treatment using propacetamol and nalbuphine was systematically prescribed. Pain, anxiety and relief were assessed with the help of visual analogue scales (VAS). Heart rate, mean blood pressure and respiratory rate were evaluated too., Results: mean postoperative pain was maximal just after recovery (6,64 +/- 2,14 cm) then decreased regularly. Initial mean score of anxiety was 3,14 +/- 3 cm and then was decreasing too. Anxiety and pain did not correlate except in 2 cases. None of the 3 objective parameters correlated with pain., Conclusion: postoperative pain can be assessed reliably after pharyngolaryngeal cancer surgery and is probably underrated. Its high initial score indicates that efforts must be focused on pre-emotive analgesia. Its high individual variability let us hypothesise that PCA systems should be effective.

Authors report a case of a neuroendocrine carcinoma (Merkel cell tumor) located in the external meatus. These tumors have a fearsome prognostic. Immunohistochemical study has become indispensable to make the diagnosis. A literature review is presented, and therapeutic choices discussed. Wide and precocious surgical resection is advised.