1,721,017 research outputs found
Iatrogenic impairment of hearing during surgery for acoustic neuroma.
No full textIsolated or combined labyrinthine, neural, and vascular damage account for failure to preserve hearing during removal of acoustic neuromas. However, the specific mechanisms of auditory impairment remain unclear unless surgical maneuvers can be related to peri- and postoperative hearing on the basis of intraoperative monitoring of auditory function.Among the different auditory monitoring techniques, recording of cochlear nerve action potentials (CNAPs) from the intracranial portion of the nerve has proven particularly useful for identifying the mechanisms of iatrogenic auditory injury.The present investigation analyzes intra- and postoperative auditory impairment in relation to surgical steps in a group of 38 subjects with acoustic neuroma (size ranging from 5 to 24 mm) undergoing removal via a retrosigmoid approach.Coagulation close to the cochlear nerve, drilling of the internal auditory canal, and removal of the intrameatal portion of the acoustic neuroma have prove to be the most critical surgical steps in hearing preservation.Changes were correlated with intra- and extrameatal tumor size, the relationship between the internal auditory canal and vestibule, and internal auditory canal enlargement, anatomic involvement of the cochlear nerve, preoperative auditory level, and ABR and ENG test findings.Changes in CNAP morphology and latency are detailed, and mechanisms of injury are analyzed and discussed as a function of these variables
Retrosigmoid approach for auditory brainstem implant.
No full textThe present paper reports our experience with the surgical retrosigmoid-transmastoid (RS-TM) technique for implanting auditory brainstem implants (ABIs). From April 1997 to August 1998, four patients with neurofibromatosis type 2 (NF2) were operated on for vestibular schwannoma removal with ABI implantation. The subjects (three men and one women) ranged in age from 22 to 31 years. Tumour size ranged from 12 to 30 mm. A classical RS-TM approach was performed. After tumour excision, identification of landmarks (VIIth, VIIIth and IXth cranial nerves, choroid plexus) to the foramen of Luschka was carefully carried out. The choroid plexus was partially removed and the tela choroidea divided and deflected. The floor of the lateral recess of the fourth ventricle and the convolution of the dorsal cochlear nucleus became visible. The electrode array was then inserted into the lateral recess and placed in the correct position with the help of electrically-evoked auditory brain stem responses. Auditory sensations were induced in all patients with various numbers of electrodes. Different pitch sensations could be identified with different electrode stimulation. Details of the results are presented. In our series, the RS-TM approach represents the elective route for ABI insertion
Diode laser to treat small oral vascular malformations: A prospective case series study
No full textObjective: The current work examined a consecutive series of patients presenting vascular malformations (VMs) and venous lakes (VLs) of the lip and oral mucosa who were treated with transmucosal diode laser applications and assessed over a 1 year period. Study Design and Methods: Fifty-nine patients (31 males and 28 females) presenting low-flow VMs or VLs of the oral cavity were treated transmucosally using a diode laser (with an 830 nm operating wavelength and 1.6 W output power) with a 320 μm diameter flexible fiber. All the lesions were assessed 7 days, 30 days, and 1 year after the laser treatment, and the lesion reduction percentage was scored on a one to five scale. The patients were also asked to assess their pain perception daily during the 7 days following the treatment using a visual analog scale (VAS). Results: There were no procedure-related intra- or post-operative complications; only modest pain intensity was reported. Thirty days after the treatment, lesion reduction was..
Hearing Restoration During Vestibular Schwannoma Surgery With Transcanal Approach: Anatomical and Functional Preliminary Report
No full textObjective: Hearing restoration has always been a dream in vestibular schwannoma (VS) surgery. The aim of this study is to describe an endoscopic assisted transcanal retrocochlear approach to the internal auditory canal (IAC) with total removal of the VS; simultaneously we assessed the anatomical and functional aspects of hearing restoration with cochlear implant (CI). Study Design: A retrospective case series. Setting: Tertiary referral center. Patients: Six patients affected by VS involving the fundus of the IAC (Koos stage I–II) were included in this study. The patients already demonstrated symptoms of IAC involvement by the neuroma, with severe to profound hearing loss. Interventions: Transcanal microscopic, endoscopic assisted, approach was chosen for total tumor removal. Preoperative and intraoperative electrophysiological monitoring was performed using electrically evoked auditory brainstem responses (EABR) to evaluate preservation of cochlear function.Main Outcome and Measures: A retrospective evaluation of electrophysiological data collected during surgeries has been conducted; clinical outcomes, surgical complications, and postoperative radiological evaluations were also considered. Results: Total tumor removal was achieved in all patients with no major complications. One patient showed temporary facial palsy (HB stage II). We were able to preserve cochlear function in five out of six patients. In those patients intraoperative monitoring with EABR was performed after tumor removal with good responses. Conclusions: Transcanal retrocochlear approach for VS removal allows preservation of cochlea and cochlear nerve function. This is the first step towards developing an effective surgical technique for VS removal and hearing rehabilitation with CI
Hearing habilitation with auditory brainstem implantation in two children with cochlear nerve aplasia.
No full textPatients with aplasia and hypoplasia of the cochlear nerve have no chance of having their hearing restored by stimulating the periphery of the auditory system using the traditional cochlear implant. A possible approach to auditory rehabilitation may be direct electrical stimulation of the cochlear nuclei with an auditory brainstem implant (ABI). Recently, two children, aged 4 and 3 years, respectively, with bilateral severe cochlear malformations and cochlear nerve aplasia received an ABI. The present paper reports the technique and the preliminary results of this experience. The classic retrosigmoid approach was used. The correct position of the electrodes was estimated with the aid of EABRs and neural response telemetry (NRT). No postoperative complications were observed. High-resolution CT scans with a bone algorithm reconstruction technique were taken postoperatively to evaluate electrode placement before discharge. The ABI was activated 30 days after implantation in both patients. To date 16 and 13 electrodes, respectively, have been activated in the two children. Three months after activation the first patient had achieved good environmental sound awareness, good speech detection and some speech discrimination. The second child, 1 month after activation, had achieved good environmental sound awareness and moderate speech detection. To the best of our knowledge this is the first report of patients with hypoplasia of the cochlea and aplasia of the cochlear nerve, aged below 5 years and treated with an ABI
Updates on Larynx Cancer: Risk Factors and Oncogenesis
Full text linkLaryngeal cancer is a very common tumor in the upper aero-digestive tract. Understanding its biological mechanisms has garnered significant interest in recent years. The development of laryngeal squamous cell carcinoma (LSCC) follows a multistep process starting from precursor lesions in the epithelium. Various risk factors have been associated with laryngeal tumors, including smoking, alcohol consumption, opium use, as well as infections with HPV and EBV viruses, among others. Cancer development involves multiple steps, and genetic alterations play a crucial role. Tumor suppressor genes can be inactivated, and proto-oncogenes may become activated through mechanisms like deletions, point mutations, promoter methylation, and gene amplification. Epigenetic modifications, driven by miRNAs, have been proven to contribute to LSCC development. Despite advances in molecular medicine, there are still aspects of laryngeal cancer that remain poorly understood, and the underlying biological mechanisms have not been fully elucidated. In this narrative review, we examined the literature to analyze and summarize the main steps of carcinogenesis and the risk factors associated with laryngeal cancer
Evaluation of the central sleep apnea in asymptomatic children with Chiari 1 malformation: an open question
No full textINTRODUCTION: Type I is the most common Chiari malformation in children. In this condition, the lower part of the cerebellum, but not the brain stem, extends into the foramen magnum at the base of the skull leading to intermittent brain hypertension. In symptomatic children, central sleep apneas are shown in polysomnography evaluation. A central apnea index of 1/h or more is considered abnormal, but >5/h is clearly considered pathological. Therefore, central sleep apnea evaluation in pediatric age may show great age-related variability. METHOD AND SUBJECTS: We present three patients who were assessed by polysomnography with two different scores for central sleep apneas published in the literature: the method by Scholle (2011) and the American Academy of Sleep Medicine scoring system (2012). CONCLUSIONS: We speculated that the Scholle scoring system can be more helpful in assessing children with asymptomatic Chiari 1 malformation for a closer follow-up. More studies are needed
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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