[Interest of complex tasks on laparoscopic virtual reality simulator]. / Intérêt des tâches complexes sur simulateur de réalité virtuelle laparoscopique.

OBJECTIVES: The purpose of this study was to assess the contribution of complex tasks on virtual reality simulator (VRS) for novice surgeons in laparoscopy learning. MATERIALS AND METHODS: Fifty-five medical students were prospectively randomized in two groups (A: basic skills, n=28 and B: basic and complex skills, n=27) and then trained during two sessions on VRS. Evaluations took place before and after each training. These evaluations consisted of the achievement of an intracorporeal suture, recorded on video, with the left then with the right hand. Two independent experts evaluated those gestures blindly. RESULTS: A significant progression in terms of times and technical scores was observed in both groups between the first and the last evaluations (P between 0.001 and 0.04). Students in group B improved slower and longer than those in group A. However, left and right hands results confused did not highlight significant differences between the two groups. At the third session, the first hand to train is significantly faster in group B than in group A (P=0.04). CONCLUSION: This study found only a late and minimal impact of complex skills to reduce the execution time of intracorporeal suture. It also showed an slower and longer overall progression for those who use them compared to subjects using basic skills only.

Measurement of endolymphatic pressure.

Endolymphatic pressure measurement is of interest both to researchers in the physiology and pathophysiology of hearing and ENT physicians dealing with Menière's disease or similar conditions. It is generally agreed that endolymphatic hydrops is associated with Menière's disease and is accompanied by increased hydrostatic pressure. Endolymphatic pressure, however, cannot be measured precisely without endangering hearing, making the association between hydrops and increased endolymphatic pressure difficult to demonstrate. Several integrated in vivo models have been developed since the 1960s, but only a few allow measurement of endolymphatic hydrostatic pressure. Models associating measurement of hydrostatic pressure and endolymphatic potential and assessment of cochlear function are of value to elucidate the pathophysiology of endolymphatic hydrops. The present article presents the main types of models and discusses their respective interest.

Acoustic phase shift: objective evidence for intralabyrinthine pressure disturbance in Menière's disease provided by otoacoustic emissions.

OBJECTIVES: Still today, Menière's disease (MD) can be definitively diagnosed only on post-mortem findings of endolymphatic hydrops. Otoacoustic emission (OAE) phase has been shown to be highly sensitive to intracranial pressure. Preliminary analysis of OAEs in MD patients indicated high sensitivity to slight variations in intracranial pressure. The principal objective of the present study was to confirm this specific sensitivity of OAEs in MD. PATIENTS AND METHODS: In a prospective study of 32 consecutive cases of acute MD seen in consultation or hospital, 20 patients (23 ears) underwent acoustic phase-shift test: i.e., seated vs. supine OAE phase centered around 1kHz, with results compared to controls. RESULTS: The acoustic phase-shift test was performed in 62.5% of acute patients (58.9% of affected ears). In the control group, the 95% confidence interval for phase shift was between -30° and +45°. Phase shift was significantly elevated, beyond the normal interval, in 18 of the MD patients: range, -80° to +145°. Sensitivity was 90%. Overall, in patients in whom transient evoked OAEs (TEOAEs) were present, positive predictive value was 100% and negative predictive value 92.3%. CONCLUSIONS: The acoustic phase-shift test proved useful and powerful in demonstrating pressure imbalance in acute Menière's disease.

Patient satisfaction and functional results with the bone-anchored hearing aid (BAHA).

OBJECTIVES: To assess patient satisfaction with bone-anchored hearing aids (BAHA) and the role of preoperative audiometric testing. PATIENTS AND METHODS: A telephone satisfaction survey was conducted on all patients implanted between June 1, 2005 and February 1, 2008. Patients with unilateral total deafness underwent preoperative audiometric tests in quiet and in noise and stereoaudiometry with and without BAHA. Patients with a conductive hearing loss underwent preoperative audiometric tests in quiet and in noise and real-life testing at home using a headband. A standardized satisfaction questionnaire derived from the Entific BAHA questionnaire was used. RESULTS: Twenty-two out of 26 patients responded to the questionnaire. Ten patients were implanted for conductive hearing loss (CHL) and 12 for unilateral total deafness (UTD). Mean follow-up was 19 months in the UTD group and 21 months in the CHL group. Sixty-seven percent of UTD and 80% of CHL patients reported improved quality of life. The BAHA was worn for more than 4hours per day by 83% of UTD and 100% of CHL patients, and at least 5 days per week by 67% of UTD and 80% of CHL patients. CONCLUSION: BAHAs provided real benefit in all situations for CHL patients. In UTD, its benefit basically related to noisy environments. In UTD, satisfaction on preoperative stereoaudiometric testing in noise with and without BAHA was predictive of postimplantation satisfaction. In response to the question "Would you do it again?", 81% of patients answered "Yes".

Osteoma of the internal auditory canal.

OBJECTIVE: Osteoma occurs almost exclusively in the head and neck region, only rarely developing into the internal auditory canal. We report an incidental finding of a case in the radiological evaluation of a patient with left hemifacial spasm. PATIENTS AND METHODS: A 79-year-old woman consulted for left hemifacial spasm associated with left anacusis. Symptoms occurred up to 30 years prior to the first radiological investigations. Computed tomographic (CT) and magnetic resonance (MRI) images were taken. RESULTS: MRI demonstrated a left internal auditory canal lesion with spontaneous hypointense signal on T1- and T2-weighted images. CT showed the lesion as a typically dense and opaque osteoma. It measured 0.6 cm in maximum size. No surgery was performed because of the slow-growing features of the lesion. Clinical monitoring was recommended. CONCLUSION: Osteomas are diagnosed incidentally in asymptomatic patients. Our case was symptomatic and raised the question of surgical management. This article discusses the presentation and management associated with this exceptional osteoma location.

The remarkable cochlear amplifier.

This composite article is intended to give the experts in the field of cochlear mechanics an opportunity to voice their personal opinion on the one mechanism they believe dominates cochlear amplification in mammals. A collection of these ideas are presented here for the auditory community and others interested in the cochlear amplifier. Each expert has given their own personal view on the topic and at the end of their commentary they have suggested several experiments that would be required for the decisive mechanism underlying the cochlear amplifier. These experiments are presently lacking but if successfully performed would have an enormous impact on our understanding of the cochlear amplifier.

Non-invasive measurements of intralabyrinthine pressure changes by electrocochleography and otoacoustic emissions.

By varying the mechanical load on the stapes footplate, intralabyrinthine pressure (ILP) influences the stiffness of the middle ear and modifies its transfer function. This results in a characteristic phase shift of the otoacoustic emissions (OAEs) around 1kHz [Buki, B., Avan, P., Lemaire, J.J., Dordain, M., Chazal, J., Ribari, O., 1996. Otoacoustic emissions: a new tool for monitoring intracranial pressure changes through stapes displacements. Hear. Res. 94, 125-139]. This finding provides non-invasive means of monitoring changes of ILP and indirectly of intracranial pressure. Yet the vulnerability of OAEs to sensorineural hearing loss excludes many patients from being monitored in this manner. Being dependent on the middle-ear transfer function, the phase of the cochlear microphonic potential (CM) around 1kHz should also respond to ILP changes while being less affected by impaired hearing than OAEs. Here, normal volunteers were subjected to body tilt resulting in stepwise changes in their intracranial pressure and ILP. Their CM around 1kHz was recorded by extratympanic electrocochleography and its dependence on body position was compared to that of distortion-product OAEs. The posture-induced CM changes were also monitored in ears with sensorineural deafness and impaired OAEs to assess the usefulness of CM in the presence of hearing impairment. Last, OAEs and CM were simultaneously monitored in gerbils during intracranial pressure changes brought about via an intracranial catheter. The phase and level shifts induced by body tilt in man and intracranial pressure changes in gerbils showed up both in distortion-product OAEs and CM with similar time courses. In normally-hearing subjects, the mean phase shifts reached 16.3 degrees for CM and 41.6 degrees for OAEs, and CM remained large enough in hearing-impaired subjects for ILP to be monitored. The ratio of about two of OAEs to CM phase shifts matched the prediction of middle-ear models allowing for the fact that CM does not travel back through the middle ear while OAEs do. It follows that CM phase around 1kHz provides non-invasive access to ILP changes even if OAEs cannot be measured due to sensorineural hearing loss.

Long-term administration of magnesium after acoustic trauma caused by gunshot noise in guinea pigs.

In a previous study we observed that a 7-day post-trauma magnesium treatment significantly reduced auditory threshold shifts measured 7 days after gunshot noise exposure. However this improvement was only temporary, suggesting that it could be potentially beneficial to prolong this treatment. The aim of the present study was to evaluate the efficacy of a long-term (1 month) magnesium treatment after an impulse noise trauma, in comparison with either a 7-day magnesium treatment, an administration of methylprednisolone (conventional treatment), or a placebo (NaCl). Guinea pigs were exposed to impulse noise (three blank gunshots, 170 dB SPL peak). They received one of the four treatments, 1 h after the noise exposure. Auditory function was explored by recording the auditory brainstem response (ABR) and measuring the distortion product otoacoustic emissions (DPOAE) over a 3-month recovery period after the gunshot exposure. The functional hearing study was supplemented by a histological analysis. The results showed that a 1-month treatment with magnesium was the most effective treatment in terms of hair cell preservation. The DPOAE confirmed this effectiveness. Methylprednisolone accelerated recovery but its final efficacy remained moderate. It is probable that magnesium acts on the later metabolic processes that occur after noise exposure. Multiple mechanisms could be involved: calcium antagonism, anti-ischaemic effect or NMDA channel blockage. Regardless of the specific mechanism, a 1-month treatment with magnesium clearly attenuates NIHL, and presents the advantage of being safe for use in humans.

[Cochlear ischemia: from fundamental data to clinical hope]. / L'ischémie cochléaire : des données fondamentales aux espoirs cliniques.

OBJECTIVES: To report the known data on the functional consequences of cochlear ischemia and the tools available to detect them. METHODS: Review of the main integrated in vivo models described in mammals. RESULTS: The main integrated models of cochlear ischemia use laser doppler velocimetry to measure the degree of ischemia. Cochlear function can be effectively monitored during cochlear ischemia through the cochlear potentials and otoacoustic emissions, each of these signals giving specific information. The cochlea appears to be particularly resistant to several minutes of reversible ischemia. Indirect monitoring of cochlear ischemia can be achieved through distortion-product otoacoustic emissions during surgical procedures to the cerebellopontine angle. It is still impossible to directly and noninvasively detect cochlear ischemia in nonsurgical clinical practice. CONCLUSIONS: Integrated models of cochlear ischemia have contributed greatly to our knowledge of the functional behavior of the cochlea in this specific situation. Clinical practice now needs to be able to detect cochlear ischemia early and noninvasively, for example in cases of sudden hearing loss.

[Derivation of cerebrospinal fluid: consequences on inner ear biomechanics in adult patients with chronic hydrocephalus]. / Dérivation du liquide cérébrospinal avec valve: ses conséquences sur la biomécanique de l'oreille interne chez les patients atteints d'hydrocéphalie chronique de l'adulte.

BACKGROUND AND PURPOSE: Patients suffering from hydrocephalus are often treated by the surgical placement of a shunt, directing the excess of cerebrospinal fluid towards another body compartment. However, the degree of clinical improvement is variable and the dynamics of cerebrospinal fluid pressure in shunted hydrocephalus is poorly understood. A recently developed noninvasive technique makes it possible to follow pressure variations: it is based on otoacoustic emissions, sounds naturally emitted by the cochlea and routinely detected in audiology. When cerebrospinal fluid pressure changes, emissions undergo a phase shift while crossing the oval window. The goal of this work is to study how this shift is affected by shunt placement. METHOD: Otoacoustic emissions were recorded repeatedly in 22 adult patients who suffered from chronic hydrocephalus. Their phase shifts were measured, in sitting and recumbent positions, before and after surgical placement of a ventriculo-peritoneal shunt (Sophysa SM8). RESULTS: Postural shift in normal subjects is a phase lead, and this outcome was found in 17 of 22 patients preoperatively. After shunt placement, the postural effect became a phase lag in 18 patients of 20. In a given posture, sitting or recumbent, phase shifts changed from pre to postoperative measurements in a systematic manner. CONCLUSION: Otoacoustic emissions respond in a characteristic way to posture changes in normal adults, and having received a shunt for chronic hydrocephalus reverses the effect, presumably in relation to the existence of a "vacuum" in the inner ear.

Evaluation of mucosal surface reduction after ethmoidal surgery in nasal polyposis.

OBJECTIVES: To assess the reduction of mucosal surface after total sphenoethmoidectomy. STUDY DESIGN: Prospective study. METHODS: Twelve normal, consecutive computed tomography scans were used. Computed tomography measurements were made at two different levels: the cribriform plate, and the upper level of the maxillary antrum. The length of the lateral wall of the ethmoid sinus and the perimeter of each ethmoid cell were measured at each level and on each side. The whole perimeter of the ethmoid sinus was evaluated for each CT scan level. For each side and each level, the ratio between the ethmoid sinus perimeter and the lateral ethmoid wall length was calculated. RESULTS: The mean length of the lateral ethmoid sinus wall was 61.7+/-1.3 mm and 59.9+/-1.6 mm at the upper and lower parts of the ethmoid sinus, respectively. The mean ethmoid sinus perimeter was 263.2+/-11.5 mm and 250.4+/-11.1 mm at the upper and lower parts of the ethmoid sinus, respectively. No significant statistical difference was observed between measurements as a function of side (right or left) or level (upper or lower). The mean ratio between the ethmoid sinus perimeter and the lateral ethmoid wall length was 4.2. CONCLUSION: After total sphenoethmoidectomy, the mucosal surface of the ethmoid sinuses is reduced by a factor of 4.2; about 76 per cent of the mucosa is removed during total sphenoethmoidectomy.

[Adenocarcinomas of the ethmoid sinus: retrospective analysis of prognostic factors]. / Adénocarcinomes de l'ethmoïde: analyse rétrospective des facteurs pronostics.

OBJECTIVES: Determinate the different prognostic factors of survival in ethmoidal sinus adenocarcinomas (ADK). MATERIAL AND METHODS: 60 patients with ethmoidal sinus ADK. 59 men and one woman. Average of 62.2 years (41-82). Retrospective study between 1985 and 2005. The following data were analyzed: exposure time to wood dust, disease incidence, primary clinical symptoms and ASA score. Radiological data were recovered by tomodensitometry and magnetic resonance imaging. Histological groups were described. TNM classification according to UICC 2002 and Roux/Brasnu was established on clinical and radiological constatations. Different treatments used were analyzed. Estimate of survival rate and impact of different prognostic factors were based on Kaplan-Meier actuarial method and multivariate analysis. RESULTS: Incidence rate was 2.86 patients a year. Exposure average time to wood dust was 25.6 years (2-44). T3/T4 stages were predominant (66.7%). the survival rate was 46.5% at 5 years. The survival rate was significantly superior respectively in T1 and T2 stages than in T3 and T4 stages, and in T4a than in T4b stages. Extension of the lesion to the sphenoid sinus was revealed as a significant bad prognostic factor. The ASA score and the exposure time to wood dust were not identified as statistically significant prognosis factors. CONCLUSION: Survival factors of ethmoïd sinus ADK were T stage and the extension of the tumor to the sphenoid sinus. On the results of this study, we consider that extension in sphenoïd sinus could be include in TNM classification of ethmoïd sinus adenocarcinomas.

[The cochlea in Fabry disease: a sensorineural hearing loss model of vascular origin?]. / La maladie de Fabry: l'atteinte vasculaire multi-organe pourrait également intéresser la cochlée.

PURPOSE: Fabry disease is an inborn error of metabolism due to a deficient activity of the lysosomal enzyme alpha-galactosidase A. The enzyme defect leads to the systemic accumulation of neutral glycosphingolipids in tissues, mainly in the vascular endothelium. STRONG POINT: The aim of this paper is to present a review of the auditory manifestations in Fabry disease, and to discuss hypothesis on the vascular origin of deafness. PERSPECTIVES: Sensorineural hearing loss in Fabry disease could be the first documented vascular pathology of the inner ear.

Classification of technical pitfalls in objective universal hearing screening by otoacoustic emissions, using an ARMA model of the stimulus waveform and bootstrap cross-validation.

Transient-evoked otoacoustic emissions (TEOAE) are widely used for objective hearing screening in neonates. Their main shortcoming is their sensitivity to adverse conditions for sound transmission through the middle-ear, to and from the cochlea. We study here whether a close examination of the stimulus waveform (SW) recorded in the ear canal in the course of a screening test can pinpoint the most frequent middle-ear dysfunctions, thus allowing screeners to avoid misclassifying the corresponding babies as deaf for lack of TEOAE. Three groups of SWs were defined in infants (6-36 months of age) according to middle-ear impairment as assessed by independent testing procedures, and analyzed in the frequency domain where their properties are more readily interpreted than in the time domain. Synthetic SW parameters were extracted with the help of an autoregressive and moving average (ARMA) model, then classified using a maximum likelihood criterion and a bootstrap cross-validation. The best classification performance was 79% with a lower limit (with 90% confidence) of 60%, showing the results' consistency. We therefore suggest that new parameters and methodology based upon a more thorough analysis of SWs can improve the efficiency of TEOAE-based tests by helping the most frequent technical pitfalls to be identified.

[Contribution of cognitive and behavioral therapy for patients with tinnitus: implication in anxiety and depression]. / Apport des thérapies cognitives et comportementales dans la prise en charge des acouphènes: implication de l'anxiété et de la dépression.

OBJECTIVES: Tinnitus is a common otologic symptom but, despite important advances in the evaluation and management of such symptom, ENTs often fail to address tinnitus properly. Some tinnitus patients report that tinnitus interferes with activities of daily living, such as reading, social interactions, sleep, concentrating on complex tasks. Anxiety and depression are current major disorders associated with tinnitus. Many theories exist regarding mechanisms of tinnitus origin. A number of publications favors the theory of discordant dysfunction of inner or outer hair cells of the organ of Corti. Nevertheless, some authors insist on the possible role of the central auditory pathways. Multiple functional connections between auditory system, limbic system, autonomic nervous system seem crucial in the development of tinnitus. The aim of this paper is to present a new approach in France of tinnitus treatment by cognitive-behavioral therapy (CBT). MATERIAL AND METHODS: 96 patients with chronic and intense tinnitus were included in the study (38 females, 36 males, mean age 48 years). A CBT was developed after a clinical evaluation based on standardized questionnaires. RESULTS: The two main results are: (i) the importance of anxiety and depression in this population, (ii) the amelioration of tinnitus perception in 750f the included patients. CONCLUSION: CBT shows promise as a treatment of tinnitus-related distress.

[Adrenal insufficiency after treatment of nasal polyposis]. / Insuffisance surrénale chez les patients traités médicalement pour une polypose naso-sinusienne.

OBJECTIVE: Assessment of hypothalamic-pituitary-adrenal (HPA) axis after long term and uncontrolled corticosteroid treatment in nasal polyposis. PATIENTS AND METHODS: A short synacthen test was performed in ten patients who received uncontrolled doses of corticosteroids in a population of 128 patients treated for nasal polyposis. RESULTS: Mean yearly dose of oral prednisone administered in short-term treatment varied between 1280 and 7300 mg. Mean daily dose of inhaled beclomethasone varied between zéro and 2000 microg. Morning plasmatic cortisol was abnormal in seven the patients before and after the stimulation (respectively 140 nmole/l and 359 nmole/l). DISCUSSION: High and uncontrolled doses of corticosteroids in nasal polyposis affect HPA axis.

[Idiopathic sudden deafness]. / Les surdités brusques idiopathiques.

PURPOSE: Sudden idiopathic deafness is a sensorineural hearing loss with no recognized causes at the time of onset. The impairment site is usually localized in the cochlea, but some cases of retrocochlear lesions (e.g., cerebellopontine angle tumors, degenerative neural diseases, neuraxial ischemic lesions) can induce sensorineural deafness. The medical management of patients presenting with sudden deafness aims at detecting a causal mechanism, and at administering emergency therapeutic drugs. The diagnosis of idiopathic sudden deafness can be definitely made when no causes are found. Usually, the impairing mechanism involves the cochlea. The pathophysiology of this sensorineural alteration is still unknown. It is most likely that several mechanisms are associated together, their common point being an impairment to the feedback loop of the organ of Corti. CURRENT KNOWLEDGE AND KEY POINTS: It is very likely that reactivation of neurotropic viruses and/or cochlear ischemia are frequent etiologies. Whatever the cause, the treatment is to be administered urgently, and consists of a high-dose corticotherapy at the least. Other treatments have never really proven to be effective. It is secondarily checked that no retrocochlear pathological processes, such as a cerebellopontine angle tumor, is present, in particular in young people. FUTURE PROSPECTS AND PROJECTS: One of the current objectives is to determine when cochlear ischemia is involved, in a mini-invasive manner, such as with laser Doppler flowmetry, so that the treatment can be optimized. From a therapeutic point of view, early acoustic protection has been proven to be effective in cases of cochlear ischemia in small laboratory animals. Its efficacy in case of sudden deafness, non-exclusive of other causes than ischemia, is being assessed in a multicentric project.

Origin of cubic difference tones generated by high-intensity stimuli: effect of ischemia and auditory fatigue on the gerbil cochlea.

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.

Catheter-related upper extremity deep venous thrombosis in cancer patients: a prospective study based on Doppler US.

PURPOSE: This prospective study extending for more than 3 years had two objectives: (a) to use Doppler ultrasonography (US) to estimate the incidence of asymptomatic catheter-related upper extremity deep venous thrombosis (DVT) in a large population and (b) to study the effect of the catheter position as an individual risk factor for catheter-related DVT. MATERIALS AND METHODS: Between October 1995 and June 1998, a total of 145 patients who had oropharyngeal tract cancer and who were fitted with the same totally implantable central venous catheters (CVCs) were included in the study. Follow-up included (a) estimation of the position of each catheter tip on a chest radiograph obtained immediately after surgery and (b) regular monthly Doppler US screening for catheter-related DVT. RESULTS: Seventeen patients developed catheter-related DVT; 13 of them were asymptomatic. The mean interval between CVC implantation and detection of thrombosis was 42.2 days. Correct positioning of the distal catheter tip was associated with a significantly lower rate of catheter-related DVT. Only five of 87 patients with a correctly positioned distal catheter tip (ie, either in the superior vena cava or at the junction between the right atrium and the superior vena cava) developed thrombosis, compared with 12 of 26 patients with a misplaced catheter (P <.001). The side on which the CVC was implanted did not influence the catheter-related DVT rate. CONCLUSION: The rate of asymptomatic catheter-related DVT is high and could be lowered with correct initial CVC positioning.