Seilesh Babu

Effects of resveratrol on acoustic trauma

OBJECTIVE The purpose of the study is to test the ability of resveratrol to protect the auditory system from reactive oxygen species (ROS)-mediated noise damage. Oxidative stress is mediated by ROS, which are known to cause cellular and molecular damage. Interfering with this process, using ROS inhibitors/scavengers such as antioxidants has shown promise in protecting specific systems from oxidative damage. Among the antioxidants receiving recent attention is resveratrol, an active component in red wine. Study design and setting Ten Fischer rats were used for this study. The experimental group (n = 5) received 7 weeks of resveratrol treatment (430/microg/kg/day), by gavage, and the control group (n = 5) received normal saline solution by gavage. Baseline auditory brainstem responses (3, 6, 9, 12 and 18 kHz) were determined for both groups. After 21 days, animals were exposed to noise (105 dB, 4500 to 9000 Hz for 24 hours). Postnoise auditory brainstem responses were assessed at 4 recovery time points: immediate, at 3 days, 7 days, and 4 weeks after noise exposure. RESULTS Results demonstrate that the resveratrol group showed reduced threshold shifts compared with the control group after noise exposure. These shifts were significantly different between groups at 6 and 9 kHz (P < 0.05), corresponding to the region most represented by the frequency of the traumatic noise.Conclusion/significance Initial studies in our laboratory as well as other investigators have shown the importance of specific antioxidant therapy in the prevention of ischemic, noise, and age related hearing loss. The current study demonstrates a protective effect of resveratrol on noise-induced hearing loss.

Endoscopic vascular decompression.

Objective: This article describes the technique and reports the results of endoscopic vascular decompression (EVD) in patients with trigeminal neuralgia (TGN), hemifacial spasm (HFS), and cochleovestibular nerve compressive syndrome. Study Design: Retrospective case review. Subjects and Methods: This study evaluates the outcome and length of stay (LOS) of 20 patients who underwent EVD for vascular compressive disorders from 2005 to 2007. It also evaluates LOS in 41 patients who underwent traditional microvascular decompression (MVD) by the same surgeons from 1999 to 2004. Results: Eighty-six percent (12 of 14) patients had resolution of their TGN, and 80% (4 of 5) had resolution of their HFS. There were no major complications. The EVD patients had an average LOS of 2.36 days as compared with 4.36 days for the MVD patient group (p < 0.001). Conclusion: Endoscopic vascular decompression for patients with vascular compressive syndromes such as TGN and HFS is a safe and equally effective procedure when compared with the traditional and widely successful MVD surgery, with the added benefit of less morbidity and shorter hospital stays.

A new approach for malleus/incus fixation: no prosthesis necessary.

Objective: To describe a novel approach to manage malleus/incus fixation. Study Design: Retrospective review of 363 patients with conductive hearing loss operated on since 1996. Setting: Academic tertiary referral center. Patients: Three hundred sixty-three patients with conductive hearing loss, an intact tympanic membrane, and without history for chronic infection underwent middle ear exploration. Three hundred forty-three had otosclerosis and underwent laser stapedotomy; the remaining 20 patients had laser release of their malleus/incus fixation. Intervention: Twenty patients are presented in this paper. Nineteen patients were diagnosed with malleus fixation before surgery. One patient had a total perforation and mobility of the ossicular chain was not verified preoperatively. This patient was, intraoperatively, noted to have complete ossicular fixation. Conductive hearing loss was identified using audiometry and tuning forks. Nineteen of the 20 patients had the diagnosis confirmed using micropneumotoscopy and noting immobility of the malleus. A transcanal approach was used, and the malleus/incus fixation was released using a laser. This space was expanded upon using a drill. A 1.5–2.0 mm space was created where the ossicular fixation existed, thereby reducing the likelihood of refixation. Main Outcome Measure: Audiometric studies before and after intervention were compared. One to seven years of follow up are provided. Results: Preoperative air–bone gaps ranged from 18 dB to 51 dB and averaged 33 dB. Postoperative air–bone gaps ranged from 1–36 dB and averaged 13 dB. No patients have experienced refixation. There were two complications: one perforation requiring a tympanoplasty and one patient sustaining a 20 dB high-frequency sensorineural loss, most likely secondary to inadvertent drill contact to the ossicular chain. Conclusion: When fixation of the malleus and/or incus is found, treatment options exist. A common technique involves removal of the incus and head of the malleus and reconstruction with an incus interposition or a partial ossicular prosthesis. Another technique proposed by the senior author (M.D.S.) is maintenance of the normal anatomy and use of the potassium-titanyl-phosphate laser and drill to free the ossicles and widen the epitympanum. This series shows successful closure of the air–bone gap with this technique.

Otologic effects of topical mitomycin C: phase I-evaluation of ototoxicity.

Hypothesis: To determine ototoxicity of topical mitomycin C when placed in the middle ear at varying concentrations. Background: Despite meticulous surgical technique and diligent postoperative care, some patients develop excessive scar and granulation tissue in the middle ear or mastoid cavity. Poor wound healing may result in infection, tympanic membrane perforation, or conductive hearing loss, which may necessitate further surgery. Use of topical mitomycin C in the ear may be beneficial in reducing scar and granulation tissue formation. This phase of the study was developed to determine the safety of topical mitomycin C in the rat model relative to ototoxicity. Methods: Twelve Sprague-Dawley rats were evaluated with auditory brainstem response testing before and after treatments. Topical mitomycin C was injected in the middle ear of the right ear of eight animals. Varying concentrations of 0.125 to 0.5 mg/ml were used. Saline was injected in the left ear of each animal to serve as a control. Four separate animals were evaluated with placement of topical mitomycin C on Gelfoam into the middle ear. In two animals, Gelfoam was placed in the middle ear for 1 minute and then removed. In two animals, Gelfoam was placed in the middle ear and left in place. Auditory brainstem response testing was performed at 4 weeks and at 8 weeks. Results: Using a high concentration of mitomycin C (>0.25 mg/ml) resulted in ototoxicity, with an increase in the auditory brainstem response threshold at 4 weeks and at 8 weeks. At low concentrations (<0.20 mg/ml), no change in auditory brainstem response threshold was noted. Animals treated with Gelfoam soaked in mitomycin C showed no change in auditory brainstem response threshold. Conclusion: The results of this study indicate that topical mitomycin C on Gelfoam applied in the middle ear appears safe when low concentrations are used, even in the rat, which has a higher susceptibility to gentamycin toxicity than humans. Higher concentrations may lead to ototoxicity based on changes in Wave V on auditory brainstem response. This treatment may prove to be an important option for patients suffering from chronic granulation tissue or scar tissue in the external or middle ear.

Management of sudden sensorineural hearing loss.

Purpose of reviewSudden sensorineural hearing loss (SNHL) is an otologic emergency and should be managed quickly and effectively. This review focuses on the management of sudden SNHL, primarily idiopathic sudden SNHL as it is the most common cause. Recent findingsManagement options include observation, oral steroids, intratympanic steroids, or combined oral/intratympanic steroids. One-third to two-thirds of patients will achieve spontaneous recovery, most likely within the first 2 weeks. Despite the lack of randomized controlled trials on steroid therapy efficacy, all patients should be offered steroid treatment given low risk and possible significant benefits. All patients should undergo MRI with gadolinium to rule out retrocochlear disorder. Bilateral sudden hearing loss should alert the clinician to possible systemic disease. SummarySudden hearing loss is an otologic emergency. Appropriate counseling of patients is necessary to allow physician and patient to make a joint, educated decision. It is paramount to rule out retrocochlear disorder and to follow patients closely for improvement or need for future auditory rehabilitation.

Audiology in the sudden hearing loss clinical trial.

Objective To report the pretreatment and posttreatment population characteristics and the overall stability of the audiologic outcomes found during the Sudden Hearing Loss Clinical Trial (ClinicalTrials.gov: Identifier NCT00097448). Study Design Multicenter, prospective randomized noninferiority trial of oral versus intratympanic (IT) steroid treatment of sudden sensorineural hearing loss (SSNHL). Setting Fifteen academically based otology practices. Patients Two hundred fifty patients with unilateral SSNHL presenting within 14 days of onset with 50 dBHL or greater pure tone average hearing threshold in the affected ear. Intervention Either 60 mg/d oral prednisone for 14 days with a 5-day taper (121 patients) or 4 IT doses for 14 days of 40 mg/ml methylprednisolone (129 patients). Main Outcome Measure Primary end point was change in hearing [dB PTA] at 2 months after treatment. Noninferiority was defined as less than 10 dB difference in hearing outcome between treatments. In this article, pretreatment and posttreatment hearing findings will be reported in detail. Results A general (and stable) effect of treatment and a specific effect of greater improvement at low frequencies were found in both treatment groups. Conclusion Hearing improvements are stable, and a significantly greater improvement occurs with lower frequency after either oral or IT steroid treatment of SSNHL.

Intralabyrinthine schwannomas mimic cochleovestibular disease: symptoms from tumor mass effect in the labyrinth.

Objective To describe symptoms from intralabyrinthine schwannomas specific from more common vestibular schwannomas of the internal auditory canal or cerebellopontine angle resulting from mass effect from the tumor within the labyrinth. Patients Eight patients diagnosed as having intralabyrinthine schwannomas from 2000 to 2014 were examined retrospectively from two tertiary neurotologic centers. Interventions Diagnosis of intralabyrinthine schwannoma was made with gadolinium-enhanced magnetic resonance imaging scans. Heavily T2-weighted sequences were used to verify mass within the fluid-filled labyrinth. Patients then underwent audiometric and vestibular testing when appropriate. Treatment consisted of observation or surgical resection. Main Outcome Measures Clinical symptoms, magnetic resonance imaging scans, audiometric and videonystagmography data, and operative findings were reviewed. Results Five of the eight patients had positional vertigo or nystagmus on testing. One patient’s only complaint was positional vertigo without auditory symptoms. Three of the patients demonstrated mixed hearing loss. Two patients underwent resection of their tumors, one because of tumor growth and the other because of intractable vertigo. Conclusion These data show that a high proportion within our series displayed symptoms of positional vertigo and mixed hearing loss, which are symptoms not typical of nonintralabyrinthine schwannomas. One patient’s only reported symptom was positional vertigo. These symptoms may arise from the effect of the tumor’s mass exerted on the cochlear and vestibular end organs.

Endoscopic Resection of Vestibular Schwannomas

Objective To report our results and the technical details of fully endoscopic resection of vestibular schwannomas. Design Prospective observational study. Setting A single academic institution involving neurosurgery and neurotology. Participants Twelve consecutive patients who underwent fully endoscopic resection of a vestibular schwannoma. Main Outcome Measures Hearing preservation, based on the American Association of Otolaryngology-Head and Neck Surgeons (AAO-HNS) score as well as the Gardener and Robertson Modified Hearing Classification (GR). Facial nerve preservation based on the House-Brackmann (HB) score. Results All patients successfully underwent gross total resection. Facial nerve preservation rate was 92% with 11 of 12 patients retaining an HB score of 1/6 postoperatively. Hearing preservation rate was 67% with 8 of 12 patients maintaining a stable AAO-HNS grade and GR score at follow-up. Mean tumor size was 1.5 cm (range: 1-2 cm). No patients experienced postoperative cerebrospinal fluid leak, infection, or cranial nerve palsy for a complication rate of 0%. Mean operative time was 261.6 minutes with an estimated blood loss of 56.3 mL and average length of hospital stay of 3.6 days. Conclusion A purely endoscopic approach is a safe and effective option for hearing preservation surgery for vestibular schwannomas in appropriately selected patients.

Incidence of Pediatric Superior Semicircular Canal Dehiscence and Inner Ear Anomalies: A Large Multicenter Review.

Objective: To determine the pediatric incidence and association of superior semicircular canal dehiscence (SSCD) with inner ear (IE) anomalies. Study Design: Retrospective chart review. Setting: Two tertiary referral centers. Patients: Children less than 18 years who received a 0.5 mm or less collimated computed tomography study including the temporal bones between 2010 and 2013 for reasons including, but not limited to, hearing loss, trauma, and infection. Interventions: Images were reformatted into Pöschl and Stenver planes. Five hundred three computed tomography studies (1,006 temporal bones) were reviewed by experienced, blinded neuroradiologists. Main Outcome Measures: Incidence of SSCD and IE anomalies. Patient age, sex, and diagnosis were recorded. Statistical analysis was performed to compare outcome measures among patient demographics. Results: The incidence of SSCD was 6.2% (31/503) and an IE anomaly was 15.1% (76/503) of individuals. The incidence of SSCD with an IE anomaly was not significantly correlated (1.1%, 40/1,006; p = 0.23; LR = +1.29). The mean age of children with SSCD was lower (5.9 versus 9.8 yr; p = 0.002). SSCD incidence decreased with age (ages <2, 2–8, and 9–18 yr were 36.7%, 5.6%, and 3.2%; p<0.001) and SSC bone thickness nonsignificantly increased with age. Children with SSCD were commonly male (74.2%, p = 0.041). Conclusion: SSCD and IE anomalies are unlikely related. SSCD incidence is highest in children <2 years, with SSC bone increasing until 2 to 8 years of age. This supports the theory of a congenital precedent to SSCD, with overlying bone maturation occurring during early childhood. Age <2 years was a significant predictor of SSCD.

Utility and cost analysis of cholesteatoma histopathologic evaluation.

To evaluate the correlation between the surgeons intraoperative findings and histopathologic diagnosis of cholesteatoma specimens and the associated health care cost in requesting pathologic evaluation.