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HNO Dec 2021Hearing loss leads to impairments in communication, social interactions, and cognitive functions. This renders early treatment particularly important. A causal therapy...
BACKGROUND
Hearing loss leads to impairments in communication, social interactions, and cognitive functions. This renders early treatment particularly important. A causal therapy is not yet available. Human and animal studies have shown that certain hormones can have a positive effect on hearing.
OBJECTIVE
This review provides an overview of the effects of various hormones on hearing and describes the potential benefit for future therapeutic approaches.
MATERIALS AND METHODS
A systematic literature review of reviews dealing with the effects of various hormones on hearing in humans and animals published in PubMed between 2015 and 2020 was conducted.
RESULTS
Hormones may mediate antiapoptotic effects on structure-relevant cells of the cochlea and auditory pathway, and may influence hair cell functionality or the electrolyte balance of the endo- and perilymph. Current research focuses on glucocorticoids; the mineral corticoid aldosterone; the sex hormones estrogen, progesterone, and testosterone; the growth hormones GH (growth hormone) and IGF‑1 (insulin-like growth factor 1); thyroid hormones; and insulin. Study results are still inconsistent at this time, but various hormones appear to represent a possible future treatment option for acute hearing loss. Long-term hormone treatment, which would be necessary particularly in the case of age-related hearing loss, does not currently represent a sensible course of action due to the side effect profile of the systemic treatment/lack of practicable topical application options.
CONCLUSION
The mode of action of hormones is complex. Whether they can be used in the future for individualized treatment of patients with acute hearing impairment requires further investigation.
Topics: Animals; Cochlea; Hearing; Hearing Loss, Sudden; Hearing Tests; Hormones; Humans; Presbycusis
PubMed: 33725160
DOI: 10.1007/s00106-021-01019-y -
The Laryngoscope Jun 2020The inner ear is responsible for hearing and balance and consists of a membranous labyrinth within a bony labyrinth. The balance structure is divided into the otolith...
The inner ear is responsible for hearing and balance and consists of a membranous labyrinth within a bony labyrinth. The balance structure is divided into the otolith organ that recognizes linear acceleration and the semicircular canal that is responsible for rotational movement. The cochlea is the hearing organ. The external and middle ear are covered with skin and mucosa, respectively, and the space is filled with air, whereas the inner ear is composed of endolymph and perilymph. The inner ear is a fluid-filled sensory organ composed of hair cells with cilia on the upper part of the cells that convert changes in sound energy and balance into electric energy through the hair cells to transmit signals to the auditory nerve through synapses. Aquaporins (AQPs) are a family of transmembrane proteins present in all species that can be roughly divided into three subfamilies according to structure and function: 1) classical AQP, 2) aquaglyceroporin, and 3) superaquaporin. Currently, the subfamily of mammalian species is known to include 13 AQP members (AQP0-AQP12). AQPs have a variety of functions depending on their structure and are related to inner ear diseases such as Meniere's disease, sensorineural hearing loss, and presbycusis. Additional studies on the relationship between the inner ear and AQPs may be helpful in the diagnosis and treatment of inner ear disease. Laryngoscope, 130:1532-1539, 2020.
Topics: Animals; Aquaporins; Humans; Labyrinth Diseases
PubMed: 31593306
DOI: 10.1002/lary.28334 -
European Archives of... Dec 2022Cochlear implantation (CI) has been considered a safe and effective management option for patients with severe to profound hearing loss. Patients with enlarged... (Review)
Review
PURPOSE
Cochlear implantation (CI) has been considered a safe and effective management option for patients with severe to profound hearing loss. Patients with enlarged vestibular aqueduct (EVA) could be challenging with some variations in surgical approaches, intraoperative surgical notes, and clinical outcomes. This study aimed to review the surgical and clinical outcomes of cochlear implantation among patients with EVA.
MATERIALS AND METHODS
A systematic literature search was carried out in five major databases. All original studies reporting cochlear implantation in patients with EVA were included for qualitative data synthesis. The risk of bias was independently assessed through the National Intuitional of Health tool. The review protocol was registered in PROSPERO (reference number: CRD42021225900).
RESULTS
A total of 34 studies with 4035 subjects were included. Of them, 853 (21.14%) had EVA and underwent CI. Mondini malformation was the most frequently associated anomaly (n = 78, 11.1%). Unilateral implantation was performed in 258 cases while bilateral in 119 subjects. Postoperative complications included CSF/perilymph gusher (n = 112), CSF oozing (n = 18), and partial electrode insertion (n = 6). Closing the cochleostomy with temporalis fascia, muscle, connective tissue, or fibrin glue was the most frequently reported approach to manage CSF/perilymph gusher (n = 67, 56.7%) while packing was performed in six patients.
CONCLUSION
Patients with EVA demonstrated audiometric and speech performance improvement after CI. However, many patients had intra- or postoperative complications. Further research is needed as the outcomes may be affected by associated temporal bone pathology, the timing of implant, and hearing condition.
Topics: Adult; Child; Humans; Cochlear Implantation; Vestibular Aqueduct; Hearing Loss, Sensorineural; Postoperative Complications; Pediatrics; Retrospective Studies
PubMed: 35771280
DOI: 10.1007/s00405-022-07511-7 -
Ear and HearingThis study investigated age at implantation, improvement in hearing and speech perception outcomes, as well as surgical complications in pediatric cochlear implant...
OBJECTIVES
This study investigated age at implantation, improvement in hearing and speech perception outcomes, as well as surgical complications in pediatric cochlear implant recipients with Pendred Syndrome (PS) or non-syndromic enlarged vestibular aqueduct (NSEVA).
DESIGN
A systematic review of the literature between 1984 and 2021 was performed. Two independent reviewers performed abstract and full-text screening using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. The inclusion criteria were: English language, cochlear implant, age at implantation available, age <18 years, PS, Mondini malformation, and enlarged vestibular aqueduct. Full-text analysis was completed using the National Institute of Health assessment tool for case series and case-control studies. Studies were also graded according to the Oxford Centre for Evidence-Based Medicine grading system.
RESULTS
In total, 198 studies were identified and screened, and 55 studies were included for analysis. Audiological outcomes were available in 46 studies, and the four-frequency pure-tone audiogram average improved by 60 to 78 dB HL due to cochlear implantation. Auditory performance and speech intelligibility scores increased by 44%. The overall average implantation age was 60 months. The implantation age was 21 months lower in the studies where individuals were implanted after the year 2000 compared with those implanted before the year 2000. Perilymph gusher/oozing was the most common surgical incident reported, occurring in 187 of 1572 implantations.
CONCLUSIONS
In children with PS/NSEVA, cochlear implantation improves pure-tone average by 60 to 78 dB HL and capacity of auditory performance/speech intelligibility by 44%. The implantation age for these children has decreased during the last two decades but is still somewhat higher than reported for unselected pediatric cochlear implantation. Perilymph gusher/oozing is the most common surgical complication.
Topics: Child; Humans; Adolescent; Child, Preschool; Infant; Cochlear Implantation; Hearing Loss, Sensorineural; Cochlear Implants; Vestibular Aqueduct; Speech Perception; Retrospective Studies; Treatment Outcome
PubMed: 36397213
DOI: 10.1097/AUD.0000000000001309 -
Frontiers in Oncology 2021Hearing loss is the most common initial symptom in patients with sporadic vestibular schwannomas (SVS). Hearing preservation is an important goal of both conservative...
OBJECTIVE
Hearing loss is the most common initial symptom in patients with sporadic vestibular schwannomas (SVS). Hearing preservation is an important goal of both conservative and surgical therapy. However, the mechanism of SVS-associated hearing loss remains unclear. Thus, we performed this systematic review to summarize the current understanding of hearing loss in the SVS and distill a testable hypothesis to further illuminate its underlying mechanism.
METHODS
A systematic review querying four databases (PubMed, Medline, Embase, and Web of Science) was performed to identify studies evaluating hearing loss in patients with SVS and exploring the potential mechanisms of hearing impairment.
RESULTS
A total of 50 articles were eligible and included in this review. After analysis, the retrieved studies could be categorized into four types: (1) 29 studies explore the relationship between hearing loss and the growth pattern of the tumor (e.g., tumor size/volume, growth rate, tumor location, .); (2) ten studies investigate the potential role of cochlear dysfunction in hearing deterioration, including structural abnormality, protein elevation in perilymph, and cochlear malfunctioning; (3) two studies looked into SVS-induced impairment of auditory pathway and cortex; (4) in the rest nine studies, researchers explored the molecular mechanism underlying hearing loss in SVS, which involves molecular and genetic alterations, inflammatory response, growth factors, and other tumor-associated secretions.
CONCLUSIONS
Multiple factors may contribute to the hearing impairment in SVS, including the growth pattern of tumor, cochlear dysfunction, impairment of auditory pathway and cortex, genetic and molecular changes. However, our current understanding is still limited, and future studies are needed to explore this multifactorial hypothesis and dig deeper into its underlying mechanism.
PubMed: 34476211
DOI: 10.3389/fonc.2021.687201 -
European Archives of... Sep 2019The aim of this study is to perform a systematic literature review on the occurrence of gusher during stapes surgery, to understand its surgical management and outcomes.
OBJECTIVE
The aim of this study is to perform a systematic literature review on the occurrence of gusher during stapes surgery, to understand its surgical management and outcomes.
METHODS
The PRISMA standard was applied to identify English, Italian or French-language studies, related to stapes surgery and mentioning gusher or perilymphatic leak. Full-texts lacking information on the management of gusher and/or the post-operative hearing outcome were excluded.
RESULTS
Twenty-four articles were eventually included. Seventy-six patients were involved in the qualitative synthesis. The management of gusher mostly consisted in covering the oval window and/or filling the tympanic cavity, with absorbable and autologous graft materials. Packing of the external auditory canal was reported in 51 patients (67%). Gusher was related to complete/profound loss of hearing in 25% of the cases and to a worsening of hearing function in 31% of patients. In 19% of patients an improvement in hearing tests was reported; in 28% the hearing function was unchanged. Post-operative vestibular symptoms were reported in 7 patients, and were mainly mild and transient. The absence of vestibular symptoms was underlined in 9 cases, while in 79% of the patients the authors did not provide information.
CONCLUSION
The unexpected occurrence of gusher during stapes surgery represents a relevant issue for the otologic surgeon. Its management most commonly consists in plugging the oval window and the tympanic cavity. In most of the cases, a stapes prosthesis could be positioned. The results on hearing and vestibular functions are widely variable.
Topics: Cerebrospinal Fluid Leak; Female; Humans; Intraoperative Complications; Male; Ossicular Prosthesis; Oval Window, Ear; Perilymph; Postoperative Complications; Stapes Surgery
PubMed: 31273448
DOI: 10.1007/s00405-019-05538-x -
The Laryngoscope May 2020This study evaluates the current evidence base for total endoscopic stapes surgery, specifically to establish current efficacy and safety of the technique within...
OBJECTIVE
This study evaluates the current evidence base for total endoscopic stapes surgery, specifically to establish current efficacy and safety of the technique within clinical practice.
DATA SOURCES
A systematic review of the literature on endoscopic stapes surgery was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis checklist. A comprehensive search of PubMed, Embase, and the Cochrane Central Register of Controlled Trials database for relevant publications for all available dates with appropriate Medical Subject Headings search criteria in January 2018.
STUDY SELECTION
Out of the 160 articles identified in the search, 14 met the inclusion criteria for further analysis. Four of these were level III and 10 level IV evidence.
DATA EXTRACTION
A pooled patient population of 314 individuals was analyzed.
DATA SYNTHESIS
Documented postoperative air bone gap closure to within 20 dB was found in 95.3% of individuals (285 patients). Facial nerve palsy (temporary) occurred in three patients (0.6%), with all recovering. No total sensorineural hearing losses were recorded, but two moderate sensorineural hearing losses occurred (0.6%). Perilymph fistula was noted on four occasions (1.3%). Chorda tympani trauma was documented in 3.5% of cases, with taste disturbance documented in 13 patients (5%).
CONCLUSIONS
Our pooled analysis uses the current published evidence to establish the complication rate and audiological outcome for the endoscopic approach to stapes surgery. These outcomes are comparable to those documented in traditional use of the microscope for stapedectomy. Laryngoscope, 130:1282-1286, 2020.
Topics: Endoscopy; Hearing Tests; Humans; Postoperative Complications; Stapes Surgery; Treatment Outcome
PubMed: 31566754
DOI: 10.1002/lary.28294 -
Frontiers in Neurology 2021Capillaries within the inner ear form a semi-permeable barrier called the blood-labyrinth barrier that is less permeable than capillary barriers elsewhere within the...
Capillaries within the inner ear form a semi-permeable barrier called the blood-labyrinth barrier that is less permeable than capillary barriers elsewhere within the human body. Dysfunction of the blood-labyrinth barrier has been proposed as a mechanism for several audio-vestibular disorders. There has been interest in using magnetic resonance imaging (MRI) with intravenous gadolinium-based contrast agents (GBCA) as a marker for the integrity of the blood labyrinth barrier in research and clinical settings. This scoping review evaluates the evidence for using intravenous gadolinium-enhanced MRI to assess the permeability of the blood-labyrinth barrier in healthy and diseased ears. A systematic search was conducted of three databases: PubMed, EMBASE, CINAHL PLUS. Studies were included that used GBCA to study the inner ear and permeability of the blood-labyrinth barrier. Data was collected on MRI protocols used and inner ear enhancement patterns of healthy and diseased ears in both human and animal studies. The search yielded 14 studies in animals and 53 studies in humans. In healthy animal and human inner ears, contrast-enhanced MRI demonstrated gradual increase in inner ear signal intensity over time that was limited to the perilymph. Signal intensity peaked at 100 min in rodents and 4 h in humans. Compared to controls, patients with idiopathic sudden sensorineural hearing loss and otosclerosis had increased signal intensity both before and shortly after GBCA injection. In patients with Ménière's disease and vestibular schwannoma, studies reported increased signal at 4 h, compared to controls. Quality assessment of included studies determined that all the studies lacked sample size justification and many lacked adequate control groups or blinded assessors of MRI. The included studies provided convincing evidence that gadolinium crosses the blood-labyrinth barrier in healthy ears and more rapidly in some diseased ears. The timing of increased signal differs by disease. There was a lack of evidence that these findings indicate general permeability of the blood-labyrinth barrier. Future studies with consistent and rigorous methods are needed to investigate the relationship between gadolinium uptake and assessments of inner ear function and to better determine whether signal enhancement indicates permeability for molecules other than gadolinium.
PubMed: 34093410
DOI: 10.3389/fneur.2021.662264 -
Acta Radiologica (Stockholm, Sweden :... Oct 2021The glymphatic system (GS) is a recently discovered waste clearance system in the brain.
BACKGROUND
The glymphatic system (GS) is a recently discovered waste clearance system in the brain.
PURPOSE
To evaluate the most promising magnetic resonance imaging (MRI) sequence(s) and the most optimal sequence parameters for glymphatic MRI (gMRI) 4-24 h after administration of gadolinium-based contrast agent (GBCA).
MATERIAL AND METHODS
Multiple literature databases were systematically searched for articles regarding gMRI or MRI of the perilymph in the inner ear until 11 May 2020. All relevant MRI sequence parameters were tabulated for qualitative analysis. Their potential was assessed based on detection of low dose GBCA, primarily measured as signal intensity (SI) ratio.
RESULTS
Thirty articles were included in the analysis. Three-dimensional fluid attenuated inversion recovery (3D-FLAIR), 3D Real Inversion Recovery (3D-Real IR), and multiple 3D T1-weighted gradient echo sequences were used. In perilymph, 3D-FLAIR with a TE of at least 400 ms yielded the highest SIRs. In the qualitative analysis of inner ear studies using 3D-FLAIR, TR was in the range of 4400-10,000 ms, TI 1500-2600 ms, refocusing flip angle (rFA) (range 120°-180°), and echo train length (ETL) 23-173. In the gMRI studies, quantitative analysis was not possible. In the qualitative analysis, 3D-FLAIR was used in the majority (8/12) of the studies, usually with TR 4800-9000 ms, TI 1650-2500 ms, TE 311-561 ms, rFA 90°-120°, and ETL 167-278.
CONCLUSION
Long TE 3D-FLAIR is the most promising sequence for detection of low-dose GBCA in the GS. Clinical and/or phantom studies on other MRI parameters are needed for further optimization of gMRI.
Topics: Animals; Contrast Media; Ear, Inner; Gadolinium; Glymphatic System; Humans; Image Enhancement; Imaging, Three-Dimensional; Magnetic Resonance Imaging; Reproducibility of Results
PubMed: 33153270
DOI: 10.1177/0284185120969950