[Features of otosurgery in children after blast injuries]. / Osobennosti rekonstruktivnoi otokhirurgii u detei posle minno-vzryvnykh ranenii.

An explosion is a process that rapidly releases a huge amount of energy in the form of heat, kinetic energy, and high-pressure shock waves. Since the organ of hearing is most susceptible to pressure changes, damage to the sound-conducting or sound-receiving systems is inevitable in case of an explosive injury. This article examines the mechanism of formation of explosive injuries of the middle and inner ear in children and adolescents, the features of diagnosis and tactics of surgical reconstructive treatment of explosive ear injuries based on the data available in the scientific literature and their own experience.

El buceo recreativo y la otorrinolaringología: ¿qué sabemos y deberíamos saber? / Recreational diving and otolaryngology: what do we know and should we know?

El buceo recreativo es una práctica cada vez más popular en la población mundial, sin embargo, no está exenta de riesgos. A medida que transcurre una inmersión, el buzo es susceptible a una serie de cambios de presión que afectan las distintas cavidades que contienen aire dentro del cuerpo humano, tales como el oído, cavidades paranasales y los pulmones. Existe un gran espectro de patologías asociadas al buceo, explicándose la mayoría de ellas por el barotrauma asociado, cuya gravedad depende de la magnitud del daño asociado, pudiendo presentar desde manifestaciones a nivel local, así como también a nivel sistémico. Las patologías otológicas suelen ser las más frecuentes y el principal motivo de consulta en este tipo de pacientes. Sin embargo, las afecciones otoneurológicas, rinosinusales, de vía aérea y sistémicas pueden ser comunes dependiendo de cada perfil de buceo. Actualmente no existen recomendaciones locales sobre esta práctica, por lo que el conocimiento de la fisiología, fisiopatología y el tratamiento de las patologías otorrinolaringológicas asociadas deben ser conocidas a medida que este deporte se vuelve cada vez más popular. Se realizó una revisión de la literatura sobre las distintas afecciones otorrinolaringológicas con el fin de sistematizarlas y elaborar recomendaciones para establecer una práctica segura.

Recreational diving is an increasingly popular practice in the world; however, it is not without risks. As a dive progresses, the diver is susceptible to a series of pressure changes that affect the air-containing cavities, such as the ear, paranasal cavities, and lungs. There is a large spectrum of pathologies associated with diving, most of them being explained by associated barotrauma, the severity of which depends on the magnitude of the associated damage, could present local manifestations, as well as at systemic level. Otological pathologies are usually the most frequent and the main reason for consultation in this type of patients, however, otoneurological, rhinosinusal, airway and systemic conditions can be common depending on each diving profile. Currently there are no local recommendations on this practice, therefore, knowledge of the physiology, pathophysiology and treatment of associated otorhinolaryngological pathologies should be known as this sport becomes increasingly popular. A review of the literature on the different ear, nose and throat conditions was carried out in order to systematize them and develop recommendations to establish a safe practice.

Research progress on flat epithelium of the inner ear.

Sensorineural hearing loss and vertigo, resulting from lesions in the sensory epithelium of the inner ear, have a high incidence worldwide. The sensory epithelium of the inner ear may exhibit extreme degeneration and is transformed to flat epithelium (FE) in humans and mice with profound sensorineural hearing loss and/or vertigo. Various factors, including ototoxic drugs, noise exposure, aging, and genetic defects, can induce FE. Both hair cells and supporting cells are severely damaged in FE, and the normal cytoarchitecture of the sensory epithelium is replaced by a monolayer of very thin, flat cells of irregular contour. The pathophysiologic mechanism of FE is unclear but involves robust cell division. The cellular origin of flat cells in FE is heterogeneous; they may be transformed from supporting cells that have lost some features of supporting cells (dedifferentiation) or may have migrated from the flanking region. The epithelial-mesenchymal transition may play an important role in this process. The treatment of FE is challenging given the severe degeneration and loss of both hair cells and supporting cells. Cochlear implant or vestibular prosthesis implantation, gene therapy, and stem cell therapy show promise for the treatment of FE, although many challenges remain to be overcome.

Trauma-induced vestibular dysfunction: Possible functional repair under α1-antitrypsin-rich conditions.

Transient vestibular organ deafferentation, such that is caused by traumatic tissue injury, is presently addressed by corticosteroid therapy. However, restoration of neurophysiological properties is rarely achieved. Here, it was hypothesized that the tissue-protective attributes of α1-antityrpsin (AAT) may promote restoration of neuronal function. Inner ear injury was inflicted by unilateral labyrinthotomy in wild-type mice and in mice overexpressing human AAT. A 2-week-long assessment of vestibular signs followed. All animals responded with peak vestibular dysfunction scores within 4 h after local trauma. While wild-type animals displayed partial or no recovery across 7 days post-injury, AAT-rich group exhibited early recovery: from behavioral score 9-out-of-9 at peak to 4.8 ±â€¯0.44 (mean ±â€¯SD) within 8 h from injury, a time when wild-type mice scored 8.6 ±â€¯0.54 (p < 0.0001), and from vestibular score 15-out-of-15 to 7.8 ±â€¯2.2 within 24 h, when wild-type mice scored 13.0 ±â€¯2.0 (p < 0.01). Thus, recovery and functional normalisation of an injured vestibular compartment is achievable without corticosteroid therapy; expedited tissue repair processes appear to result from elevated circulating AAT levels. This study lays the foundation for exploring the molecular and cellular mediators of AAT within the repair processes of the delicate microscopic structures of the vestibular end organ.

[Noise-induced blood-labyrinth-barrier trauma of guinea pig and the protective effect of matrix metalloproteinase inhibitors].

Objective: The research is to study the expression and distribution of matrix metalloproteinase (MMPs)-2 and -9 in the guinea pig cochlea after noise exposure, and to explore the role of MMPs in the blood-labyrinth-barrier (BLB). In addition, the role of MMPs inhibitor doxycycline in noise-induced BLB trauma was studied as well, which provides the basis for further studies and prophylaxis of noise-induced hearing loss. Methods: A total of 45 healthy adult guinea pigs were randomly divided into the control group (15 received intraperitoneal injection of 0.9% saline for 4 consecutive days), the noise-exposure group (15 exposed by 120 dB SPL white noise for 4 h per day for continuous 2 d, intraperitoneal injection of normal saline for 4 consecutive days) and the noise-exposure + doxycycline group (15 exposed by 120 dB SPL white noise exposure for 4 h per day for 2 consecutive days, and intraperitoneal injection of doxycycline 50 mg/kg/d for 4 consecutive days), respectively. Immunofluorescence staining, western blot, and real-time quantitative PCR were used to analyze the distribution and differential expression of MMP-2 and -9 in the stria vascularis of guinea pigs in comparison with the normal control group, noise only group, and noise & doxycycline treatment group. Immunofluorescence staining was used to observe the changes in tight junction (TJ) protein ZO-1 in stria vascularis in three groups and to investigate the effect of acoustic injury on TJs. And ABR tests were utilized to detect the hearing function of guinea pigs in the three groups. Intravenous Evans blue was administrated intravenously as an indicator of vascular leakage among three groups to study the changes in BLB permeability in context of acoustic injury. SPSS 22.0 was used for statistical analysis. Results: There was no significant difference in hearing function between the noise-exposure group and the noise & doxycycline group two hours after noise exposure. After seven, 14 and 28 days noise exposure, the hearing recovery of the noise & doxycycline treatment group was significantly greater than that of the noise-exposure group (P<0.05) . Immunofluorescence staining showed that there was only a small amount of MMP-2 and -9 in the stria vascular in the normal control group, and ZO-1 showed dense linear expression. While, in the noise-explore group, MMP-2 and -9 in the stria vascular was significantly elevated (P<0.05), and the configuration of ZO-1 became loose and discontinuous. However, the MMP-2 and -9 in the noise & doxycycline treatment group were not significantly different from the normal control group (P>0.05), which were significantly less than that in the noise-exposure group, and just a little break of ZO-1 was observed, however, the overall structure remained dense. The leakage of Evans blue from stria vascular capillary in the noise-exposure group was significantly increased, and the difference between the other two groups did not show any statistical significance (P>0.05). Conclusions: The damage of tight junction structure induced by MMP-2 and -9 may play an important role in BLB destruction. In addition, doxycycline can inhibit MMPs secretion, thereby, to some extent, protecting the integrity of BLB from acoustic injury, and contributing to the long-term hearing recovery.

Radiological evaluation of inner ear trauma after cochlear implant surgery by cone beam CT(CBCT).

PURPOSE: Cochlear implantation (CI) has been extended to involve younger age group with higher incidence of residual hearing which increases the need of minimizing surgical inner ear trauma. Radiological evaluation for electrode position has been studied yet without assessment of inner ear trauma, our objective is radiological evaluation of post cochlear implantation inner ear trauma MATERIAL AND METHODS: 20 patients with CI for pre lingual SNHL were included in this study. Cone beam CT (CBCT) was used for evaluation of electrode position and assessment of inner ear trauma. A Neuroradiologist and an implant surgeon analyzed the relation of inserted electrode to the intra-cochlear structures, with introduction of novel radiological grading for inner ear trauma. RESULTS: The mean major cochlear diameter was 8.9 mm, the mean angular depth of insertion was 406.9944 (SD = 165.0559). Ten patients were with no cochlear trauma (grade 0), three patients were grade 1, two patients were grade 2 and five patients were grade 3 inner ear trauma. CONCLUSION: Radiological evaluation for electrode position should extend to involve assessment of inner ear trauma using relation of the implant to cochlear internal structures which could be performed by CBCT with high resolution and least metallic artifacts.

Electrical Impedance as a Biomarker for Inner Ear Pathology Following Lateral Wall and Peri-modiolar Cochlear Implantation.

OBJECTIVES/HYPOTHESIS: Spikes in cochlear implant impedance are associated with inner ear pathology after implantation. Here, we correlate these spikes with episodes of hearing loss and/or vertigo, with a comparison between lateral wall and peri-modiolar electrode arrays. METHODS: Seven hundred seventy recipients of Cochlear's slim-straight, lateral wall electrode (CI422), or peri-modiolar (CI512) electrode were investigated for impedance spikes. Impedance fluctuations were defined as a median rise of ≥ 4 kΩ across all intracochlear electrodes from baseline measurements taken 2 weeks after switch-on. Medical records were analyzed from 189 of the 770 patients. RESULTS: The slim straight, lateral wall electrode was found to spike in impedance at a significantly higher rate than the peri-modiolar array (17% vs 12%). The peri-modiolar electrode tended to spike in impedance earlier than the slim-straight electrode. Impedance spikes were found to significantly correlate with medical events (hearing loss, vertigo, or tinnitus). Overall, in the "spike" group, 42 of 75 patients (56%) demonstrated a clinical event during the impedance spike, whereas 26 of 114 patients (22%) of the "non-spike" group had a clinical event. This significant difference existed with both implant types. CONCLUSION: These results demonstrate a small, but significant increase in impedance spikes in lateral wall electrodes, and support the relationship between spikes in cochlear implant impedances and postoperative inner-ear events, including the loss of residual hearing and vertigo. Monitoring cochlear implant impedance may be a method for early detection, and so the prevention, of these events in the future.

Otolin-1, as a Potential Marker for Inner Ear Trauma after Mastoidectomy.

OBJECTIVES: The aim of this prospective clinical study was to examine the negative effect of drilling by measuring peripheral Otolin-1 levels as a potential biomarker. MATERIALS AND METHODS: Patients who underwent mastoidectomy due to chronic otitis media were included in the study. Otolin-1 levels were measured preoperatively and 6 h postoperatively, and total drilling time was noted. Preoperative serum Otolin-1 levels in 31 patients were compared with those in31 age- and sex-matched healthy individuals. Pre- and postoperative serum Otolin-1 levels were also compared. RESULTS: Tympanoplasty was performed through canal wall-down (n=17) and wall-up mastoidectomy (n=14) in our sample. The mean duration of drilling was 52.7±13.8min. Preoperative serum Otolin-1 levels were significantly lower in patients than in healthy controls (21.0±3.0 vs. 23.5±3.9 pg/mL, p=0.006). We also found significantly higher postoperative serum Otolin-1 levels than preoperative levels (21.0±3.0 vs. 27.0±6.9 pg/mL, p<0.001). An increase in serum Otolin-1 levels during surgery was independently associated with drilling time in multivariate linear regression analysis (r=0.309, p<0.001). CONCLUSION: A nearly postoperative increase in serum Otolin-1 levels after mastoidectomy was independently associated with drilling time. We show that serum Otolin-1 levels may be used to indicate inner ear trauma in clinical practice in the future.

Direct cellular reprogramming and inner ear regeneration.

INTRODUCTION: Sound is integral to communication and connects us to the world through speech and music. Cochlear hair cells are essential for converting sounds into neural impulses. However, these cells are highly susceptible to damage from an array of factors, resulting in degeneration and ultimately irreversible hearing loss in humans. Since the discovery of hair cell regeneration in birds, there have been tremendous efforts to identify therapies that could promote hair cell regeneration in mammals. AREAS COVERED: Here, we will review recent studies describing spontaneous hair cell regeneration and direct cellular reprograming as well as other factors that mediate mammalian hair cell regeneration. EXPERT OPINION: Numerous combinatorial approaches have successfully reprogrammed non-sensory supporting cells to form hair cells, albeit with limited efficacy and maturation. Studies on epigenetic regulation and transcriptional network of hair cell progenitors may accelerate discovery of more promising reprogramming regimens.

Inner Ear Damage by Firecracker Trauma.

Firecrackers are still popular among the general public of various populations worldwide. This study investigated inner ear damage in patients with firecracker trauma and analyzed noise levels in 6 kinds of commercially available firecrackers. During the past 20 years, we have experienced 30 patients with firecracker trauma. An inner ear test battery comprising audiometry, cervical and ocular vestibular-evoked myogenic potential (cVEMP and oVEMP) tests and a caloric test was performed. The real-time noise levels were measured outdoors at a distance of 2, 4 and 6 m away from a lighting firecracker to mimic a noise event. Mean hearing levels at high frequencies (4,000 and 8,000 Hz) were significantly higher than those at the low and middle frequencies, indicating that firecrackers mostly cause high-tone hearing loss. For the vestibular damage, abnormality percentages were higher in the results of cVEMP (80%) and oVEMP (60%) tests, but not in the caloric test (8%). In conclusion, most firecrackers exhibited noise levels > 110 dB SPL even at a distance of 6 m. This blast injury simultaneously damaged the cochlea, saccule and utricle, but spared the semicircular canals, indicating that blast exposure potentiates the adverse effect of noise exposure on both cochlear and vestibular partitions.

Inner ear barotrauma in divers: an evidence-based tool for evaluation and treatment.

OBJECTIVE: To systematically search the literature for studies evaluating the typical presentation and testing that is performed for divers with inner ear symptoms and then to create a tool for clinicians when evaluating a diver with inner ear symptoms. METHODS: Nine databases, including PubMed/MEDLINE were systematically searched through 31 January 2018. The PRISMA statement was followed. RESULTS: Three-hundred and two manuscripts were screened, 69 were downloaded and 21 met criteria to be included in this review. The articles were evaluated for symptomatic trends and initial evaluation work-up primarily focusing on inner-ear barotrauma (IEBt) and inner ear decompression sickness (inner ear DCS). The trends for IEBt were compared to typical inner ear DCS presentation based on large study inner ear DCS results consistent with the plethora of research available. Finally, the HOOYAH Tool was developed to assist the receiving provider to better determine the most likely diagnosis and thus initiate appropriate treatment. The HOOYAH Tool is comprised of the following: 1) H: hard to clear; 2) O: onset of symptoms; 3) O: otoscopic exam; 4) Y: your dive profile; 5) A: additional symptoms and 6) H: hearing. For each of these components, the typical presentation is described allowing the provider better to discern the correct diagnosis. CONCLUSION: The diagnosis of IEBt remains difficult to define short of visualization through surgical exploration. Early treatment is defined by conservative management with a subsequent observational period to determine symptomatic resolution and need for surgery. However, a similar differential diagnosis is inner ear DCS which requires early recompression. The HOOYAH tool provides a method for assisting the provider in forming a more confident decision regarding the underlying pathology and facilitation of the appropriate treatment.

Hearing loss in pediatric temporal bone fractures: Evaluating two radiographic classification systems as prognosticators.

INTRODUCTION: Temporal bone fractures (TBF) are traditionally classified by their angle of fracture relative to the petrous ridge, and more recently by whether or not they violate the otic-capsule. This study compared rates of hearing loss (HL) and signs of otologic dysfunction among fracture types of both classification systems, within the pediatric population. METHODS: Pediatric patients were retrospectively characterized from a previously identified cohort of TBF patients, diagnosed from 2000 to 2014. CT scans were reviewed and TBFs were classified first as longitudinal (L), transverse (T) or mixed (M), and then as otic-capsule sparing (OCS) or otic-capsule violating (OCV). Medical records were reviewed, and rates of HL and presenting signs were compared among L, T and M fractures, and OCS and OCV fractures. RESULTS: Forty-three patients with 47 TBFs met the inclusion criteria. Eighteen, 4 and 25 TBFs were classified as L, T and M fractures, respectively. Thirty-three and 9 were classified as OCS, and OCV, respectively. Among 24 cases of HL: 20, 3, and 1 were conductive HL (CHL), sensorineural HL (SNHL) and mixed HL, respectively. Two cases of SNHL were found among OCV fractures, with none in OCS fractures (estimated difference 0.22; 95% confidence interval 0.01-0.60). Similar rates of CHL were found across L, T and M fractures (range 36-50%), and across OCV and OCS fractures (range 42-44%). Hemotympanum was the most common presenting sign, found in 68% of TBFs and 80% of CHL cases. There were no significant differences in the incidence of signs or symptoms between fracture types. CONCLUSIONS: In our cohort, both the traditional and otic-capsule radiographic classification systems failed to predict the incidence of CHL and other otologic signs in the pediatric population. Though OCV fractures conferred an increased risk for developing SNHL, we found a lower incidence than anticipated given violation to the bony labyrinth.

Imagen de la hipoacusia postraumática / Imaging of post-traumatic hearing loss

Objetivo. La hipoacusia es la complicación más frecuente del traumatismo del hueso temporal. El papel del radiólogo es de gran importancia; la adecuación y la selección de las pruebas radiológicas, así como su correcta interpretación, son cruciales para establecer el diagnóstico y el pronóstico, y para seleccionar el tratamiento idóneo. Con el objetivo de sistematizar los conceptos más relevantes en la valoración de los estudios de imagen en este contexto, se esquematizará el desarrollo del tema según el tipo de hipoacusia que condicione el traumatismo. De forma ordenada se valorarán las potenciales lesiones de sus componentes; en cada caso se sugerirá la técnica de imagen para su evaluación y se describirán e ilustrarán los hallazgos. Conclusión. En la hipoacusia postraumática, la tomografía computarizada es la técnica de elección inicial y permitirá la detección de alteraciones que condicionen hipoacusia conductiva; la resonancia magnética es útil en la valoración de la hipoacusia neurosensorial

Objective. Hearing loss is the most frequent complication of temporal bone trauma. The role of the radiologist is of great importance; the adequacy and selection of the imaging technique, as well as its correct interpretation, are crucial to establish the diagnosis, prognosis and enable the selection of appropriate treatment. With the aim of systematizing the most relevant concepts in the evaluation of image studies in this scenario, this review will be outlined according to the hearing loss type. The potential lesions of its components will be assessed; In each case the most appropriate imaging technique will be suggested and the findings will be described and depicted. Conclusion. In postraumatic hearing loss, computed tomography is the initial technique of choice and will allow the detection of alterations that cause conductive hearing loss; magnetic resonance imaging will be useful in the evaluation of sensorineural hearing loss

Bilateral inner ear damage after electrical injury: A case report.

Electrical injury occurs as a result of direct contact with an electrical source. We present the case of a 62-year-old male patient, an electrician by profession, who was hit by a high-voltage electrical current while working with cables in proximity to a wet floor. The patient suffered from immediate loss of consciousness and five days later he started complaining of slight hearing loss, persistent vertigo, instability and bilateral tinnitus. A thorough audiological and vestibular examination revealed an extensive bilateral vestibulocochlear dysfunction. The exact pathogenetic mechanisms of inner ear dysfunction after electrical injury have not been fully elucidated, although it is believed that there is significant improvement with time. Long-term follow-up, medical assistance and psychological support are crucial factors for the patient management.

Prevalence and Risk Factors for Hearing Loss in Chilean Shellfish Divers.

BACKGROUND: Diving within artisanal fishing is a profession carried out by many men in coastal communities of southern Chile. These shellfish divers use surface supplied air for breathing. Among potential health threats are occupational accidents, decompression sickness and barotrauma. Repeated middle and inner ear barotrauma and decompression sickness of the ear may result in hearing loss. OBJECTIVE: To determine the prevalence of hearing loss and related risk factors in artisanal shellfish divers. METHODS: A cross-sectional study including 125 male shellfish divers was carried out in a coastal village in southern Chile. Participants were interviewed using a standard Spanish questionnaire adapted for this population. Hearing loss was assessed through audiometry. Any hearing loss, sensorineural hearing loss and other types of hearing loss (conduction, unilateral and mixed) were used as the outcomes. Bivariate and multiple logistic regression models were carried out to identify risk factors for hearing loss. FINDINGS: Median duration on the job was 25 years (range 1-52), 64% of divers had a low level of schooling and 52% reported not knowing how to use decompression tables. Most (86%) of the divers dove deeper than 30 meters exceeding the 20 meters permitted by law. The majority (80%) reported having experienced several episodes of type II decompression sickness during their working life. The prevalence of any type of hearing loss was 54.4%: 29.0% presented sensorineural hearing loss and 25.6% presented other types of hearing impairment. After adjustment for age and other potential risk factors, diving more than 25 years was the main predictor for all kinds of hearing loss under study. CONCLUSIONS: Hearing loss is frequent in artisanal shellfish divers and safety measures are limited. Although based on small numbers and lacking an unexposed comparison group, our results suggest the need for community-based interventions.

[The type of traumatic sensorineural hearing loss affects diagnostic and medico-legal assessment].

Traumatic sensorineural hearing loss (TSHN) is mostly a high-frequency loss resembling noise-induced hearing loss (NIHL). However, approx. 25% of TSHN audiograms differ from NIHL in being of the slope, flat or low-frequency type. The physical properties of the trauma influence the audiogram shape, and the great individual variation of susceptibility to TSHN indicates the importance of genetic factors as well. As TSHN, like NIHL, predominantly is of a metabolic rather than a mechanical nature, its magnitude and configuration may change considerably during the first weeks after the causative incident.

A Simple Model for Inducing Optimal Increase of SDF-1 with Aminoglycoside Ototoxicity.

OBJECTIVES: As a homing factor of stem cell, stromal derived factor-1 (SDF-1) is important for the regenerative research in ototoxicity. Mice models with aminoglycoside ototoxicity have been widely used to study the regeneration capacity of MSCs in repair of cochlear injury. We developed a mouse model with maximal increase in SDF-1 levels in the inner ear, according to the "one-shot" doses of kanamycin and furosemide. METHODS: C57BL/6 mice had kanamycin (420, 550, and 600 mg/kg) dissolved in PBS, followed by an intraperitoneal injection of furosemide (130 mg/kg). The injuries of inner ear were measured with hearing thresholds, histology, and outer hair cell counts at 0, 3, 5, 7, 10, and 14 days before the sacrifice. The levels of SDF-1 in the inner ear were tested by real-time RT-PCR and immunohistochemistry. RESULTS: There were a significant reduction in hearing thresholds and a maximal increase of SDF-1 levels in the furosemide 130 mg/kg + kanamycin 550 mg/kg group, but severe hearing deterioration over time was observed in the furosemide 130 mg/kg + kanamycin 600 mg/kg group and four mice were dead. SDF-1 was detected mostly in the stria vascularis and organ of Corti showing the highest increase in expression. CONCLUSION: We observed optimal induction of the stem cell homing factor in the newly generated aminoglycoside-induced ototoxicity mouse model using a "one-shot" protocol. This study regarding high SDF-1 levels in our mouse model of ototoxicity would play a major role in the development of therapeutic agents using MSC homing.

Damage to inner ear structure during cochlear implantation: Correlation between insertion force and radio-histological findings in temporal bone specimens.

Cochlear implant insertion should be as least traumatic as possible in order to reduce trauma to the cochlear sensory structures. The force applied to the cochlea during array insertion should be controlled to limit insertion-related damage. The relationship between insertion force and histological traumatism remains to be demonstrated. Twelve freshly frozen cadaveric temporal bones were implanted with a long straight electrodes array through an anterior extended round window insertion using a motorized insertion tool with real-time measurement of the insertion force. Anatomical parameters, measured on a pre-implantation cone beam CT scan, position of the array and force metrics were correlated with post-implantation scanning electron microscopy images and histological damage assessment. An atraumatic insertion occurred in six cochleae, a translocation in five cochleae and a basilar membrane rupture in one cochlea. The translocation always occurred in the 150- to 180-degree region. In the case of traumatic insertion, different force profiles were observed with a more irregular curve arising from the presence of an early peak force (30 ± 18.2 mN). This corresponded approximately to the first point of contact of the array with the lateral wall of the cochlea. Atraumatic and traumatic insertions had significantly different force values at the same depth of insertion (p < 0.001, two-way ANOVA), and significantly different regression lines (y = 1.34x + 0.7 for atraumatic and y = 3.37x + 0.84 for traumatic insertion, p < 0.001, ANCOVA). In the present study, the insertion force was correlated with the intracochlear trauma. The 150- to 180-degree region represented the area at risk for scalar translocation for this straight electrodes array. Insertion force curves with different sets of values were identified for traumatic and atraumatic insertions; these values should be considered during motorized insertion of an implant so as to be able to modify the insertion parameters (e.g axis of insertion) and facilitate preservation of endocochlear structures.