Cochlear implants (CIs) are widely used to provide auditory rehabilitation to individuals having severe to profound sensorineural hearing loss (SNHL). However, insertion of electrode leads to inner trauma and activation of inflammatory and apoptotic signaling cascades resulting in loss of residual hearing in implanted individuals. Pharmaceutical interventions that can target these signaling cascades hold great potential for preserving residual hearing by preventing sensory cell damage. Bile salts have shown efficacy in various regions of the body as powerful antioxidants and anti-inflammatory agents. However, their efficacy against inner ear trauma has never been explored. The objective of this study was to determine whether taurodeoxycholic acid (TDCA), a bile salt derivative, can prevent sensory cell damage employing an in vitro model of electrode insertion trauma (EIT). The organ of Corti (OC) explants were dissected from postnatal day 3 (P-3) rats and placed in serum-free media. Explants were divided into control and experimental groups: (1) untreated controls; (2) EIT; (3) EIT+ TDCA (different concentrations). Hair cell (HC) density, analyses of apoptosis pathway (cleaved caspase 3), levels of reactive oxygen species (ROS) as well as inducible nitric oxide synthase (iNOS) activity and Mitochondrial Membrane Potential (MMP) were assayed. Treatment with TDCA provided significant otoprotection against HC loss in a dose-dependent manner. The molecular mechanisms underlying otoprotection involved decreasing oxidative stress, lowering levels of iNOS, and abrogating generation of cleaved caspase 3. The results of the present study suggest that TDCA provides efficient otoprotection against EIT, in vitro and should be explored for developing pharmaceutical interventions to preserve residual hearing post-cochlear implantation.
Background: Electrode insertion trauma (EIT) during cochlear implantation (CI) can cause loss of residual hearing. L-N-acetylcysteine (L-NAC) and dexamethasone (Dex) have been individually shown to provide otoprotection albeit at higher concentrations that may be associated with adverse effects. Objective/Aims: The aim of this study is to determine whether L-NAC and Dex could be combined to decrease their effective dosage. Materials and Methods: The organ of Corti (OC) explants were divided into various groups: 1) control; 2) EIT; 3) EIT treated with different concentrations of Dex; 4) EIT treated with different concentrations of L-NAC; 5) EIT treated with L-NAC and Dex in combination. Hair cell (HC) density, levels of oxidative stress, proinflammatory cytokines and nitric oxide (NO) was determined. Results: There was a significant loss of HCs in explants subjected to EIT compared to the control group. L-NAC and Dex in combination was able to provide significant otoprotection at lower concentrations compared to individual drugs. Conclusions and Significance: A combination containing L-NAC and Dex is effective in protecting sensory cells at lower protective doses than each compound separately. These compounds can be combined allowing a decrease of potential side effects of each compound and providing significant otoprotection for EIT.
Recent advancements in stem cell therapy have led to an increased interest within the auditory community in exploring the potential of mesenchymal stem cells (MSCs) in the treatment of inner ear disorders. However, the biocompatibility of MSCs with the inner ear, especially when delivered non-surgically and in the immunocompetent cochlea, is not completely understood. In this study, we determined the effect of intratympanic administration of rodent bone marrow MSCs (BM-MSCs) on the inner ear in an immunocompetent rat model. The administration of MSCs did not lead to the generation of any oxidative stress in the rat inner ear. There was no significant production of proinflammatory cytokines, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6 and IL-12, due to BM-MSCs administration into the rat cochlea. BM-MSCs do not activate caspase 3 pathway, which plays a central role in sensory cell damage. Additionally, transferase dUTP nick end labeling (TUNEL) staining determined that there was no significant cell death associated with the administration of BM-MSCs. The results of the present study suggest that trans-tympanic administration of BM-MSCs does not result in oxidative stress or inflammatory response in the immunocompetent rat cochlea.
Background:Organophosphate compound (OPC) poisoning is common in the developing countries such as India. The acute and later effects of OPC poisoning on pituitary and target gland hormones is largely unknown.Materials and Methods:This prospective study was conducted at Postgraduate Institute of Medical Education and Research between January 2012 and March 2013. Fourteen patients (8 males, age 18-50 years) with acute OPC poisoning were included in the study based on the history and clinical features, documented decreased in plasma cholinesterase activity or presence of the OPC in gastric lavage/blood samples. The hormonal parameters were done at baseline, at the time of discharge and at three months of follow-up.Results:A total of 14 patients out of 46 with the mean age of 30.1 ± 10.3 years were finally eligible for the study. Hormonal alterations at admission were similar to sick euhormonal syndrome. Overall 7 of them had nine hormonal deficits at three months of follow up, 4 having sub normal basal cortisol level and two each had low testosterone and growth hormone and only one had thyroxine deficiency.Conclusion:Acute organophosphate poisoning results in endocrine dysfunction akin to sick euhormonal syndrome. However, in a small subset of patients, varying level of hormonal insufficiency may occur either at admission or later. These observations need re-validation in a larger group of patients with specific OPC.
Background Till date, there have been no studies that have analyzed a database to examine postmarket adverse events associated with PROPEL mometasone furoate bioabsorbable drug-eluting sinus stents. Objective To determine the postmarket complications associated with PROPEL mometasone furoate bioabsorbable drug-eluting sinus stents. Methods The US Food and Drug Administration’s Manufacturer and User Facility Device Experience database was searched for adverse events associated with PROPEL bioabsorbable drug-eluting sinus stents between January 1, 2012 and December 31, 2020. Data were extracted and analyzed from medical device reports (MDRs) that involved sinus stents. Results After 47 MDRs were identified, 25 reports involving PROPEL bioabsorbable drug-eluting sinus stents were reviewed, from which 40 adverse events were recorded. Of these, there were 32 adverse events to patients and 8 device malfunctions. The most common adverse events to patients included infection (21.8%), oropharyngeal obstruction (15.6%), and headache/pain (12.5%). The most common device malfunction reported was migration and expulsion of the stent (87.5%). Conclusions PROPEL sinus stents have been shown to be effective in preventing sinus outflow obstruction after functional endoscopic sinus surgery. Both adverse events to patients and device malfunctions are reported infrequently. A more comprehensive understanding of rare postmarket complications seen with PROPEL sinus stents may further aid informed decision-making regarding their usage.
Objective: To systematically appraise the implementation of cochlear implantation (CI) in Usher Syndrome (USH) Types 1, 2, and 3 patients, and analyze who would benefit from CI. Data Sources: A comprehensive search of PubMed, Embase, CINAHL, and Cochrane Library electronic databases from inception through June 2020 was performed. There were no language restrictions. Study Selection: The PRISMA strategy was followed. Included studies discuss USH patients who underwent CI regardless of age, nationality, or clinical subtype. All included studies report post-implantation functional, cognitive, or quality of life outcomes. Only reviews were excluded. Results: Fifteen studies met the inclusion criteria. USH patients experienced improvements in PTA and speech perception and expression outcomes after CI, as well as improvements in phonological memory and quality of life measures. Overall, patients implanted at younger ages outperformed older patients in audiological testing. Similarly, patients with prolonged auditory deprivation had relatively poor performance outcomes in sentence recognition and speech detection following CI. Conclusions: Most USH patients benefit from CI. USH patients who undergo CI at younger ages generally achieve better hearing, speech, and cognitive outcomes. CI at older ages can still prove beneficial if appropriate auditory amplification is started at the right time. Further research is warranted to fill the gap in understanding regarding the gene mutations underlying the pathophysiology of USH that have favorable CI outcomes as well as the optimal time to perform CI.
Background Delays in the diagnosis and therapy of benign paroxysmal positional vertigo can greatly impact quality of life and increase healthcare costs for patients. This study aimed to appraise the quality of clinical practice guidelines for the diagnosis and management of benign paroxysmal positional vertigo. Methods A comprehensive database search of clinical practice guidelines was completed up to 30 October 2021. Four independent reviewers used the Appraisal of Guidelines for Research and Evaluation II instrument in the quality appraisal. Results The highest score was in ‘clarity and presentation’ (58.33 ± 22.7). The lowest score was in ‘applicability’ (13.96 ± 30.1). Overall, four clinical practice guidelines were ‘low quality’ and only one guideline was ‘high quality’. Conclusion This review identified a significant lack of quality in clinical practice guideline development for benign paroxysmal positional vertigo, highlighting the need for a more rigorous approach for future guideline development.
A 75-year-old woman presented with a 6-to 8-month history of new-onset headaches, dizziness, and difficulty concentrating to an outside otolaryngologist. Outside imaging was concerning for possible cholesteatoma of the left temporal bone, necessitating a left cortical mastoidectomy. Intraoperatively, a sinodural angle neoplastic process was encountered. Biopsies were taken, and the procedure was terminated. Permanent pathology revealed a benign hemangioma, prompting referral of the patient to our tertiary care center for further treatment.The patient continued to report headaches with additional complaints of left aural fullness and hearing loss. Audiometry revealed a right mild to moderate high-frequency sensorineural hearing loss and left-sided mild to moderate mixed hearing loss from 125 to 6,000 Hz with severe loss at 8,000 Hz, with an air-bone gap ranging from 20 to 30 dB in all frequencies. Bilateral word recognition scores were 100%. The case, including pertinent imaging and pathology, was reviewed at a multidisciplinary tumor board.High-resolution computed tomography (CT) of the temporal bone demonstrated a well-marginated, expansile lesion that measured about 12.3 Â 13.8 mm in the left mastoid bone (Fig. 1, A and B). The lesion was associated with an intact outer table with focal erosion of the sinodural plate and demonstrated a honeycomb pattern of radiating trabeculae.Magnetic resonance angiography showed an expansile, irregular, lobulated isointense T1 and a high T2 signal intensity mass lesion in the left mastoid that demonstrated heterogeneous contrast enhancement on postcontrast T1-weighted images (Fig. 2, A-E). Scattered low T1 signal intensity foci in the lesion were observed on both the precontrast and postcontrast images, which likely represent flow voids as seen on the axial gradient-echo sequence (Fig.
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