RELEVANT PATIENT GROUP: adult patients (age 18 years and older) who present with sudden hearing loss (SHL) THE IMPORTANT HEALTH-RELATED BENEFITS AND HARMS YOU ARE INTERESTED IN, FOR EXAMPLE, IMPROVEMENTS IN SYMPTOMS OR PROBLEMS WITH DIAGNOSIS: Q1. A. What is the effectiveness of corticosteroid treatment vs a placebo for SHL? B. What criteria should be used to determine at what level of hearing recovery intratympanic steroids would be offered as salvage for SHL? C. What is the value of combined therapy (i.e., oral and intratympanic steroids) in patients with SHL? D. What is the optimal dose and duration of initial corticosteroid therapy (oral and intratympanic) of SHL? E. How long after onset of SHL are oral/transtympanic steroid therapy effective as primary therapy ( 1week, 2weeks, ...)? F. What is the optimal dose and duration of salvage therapy using intratympanic steroids? G. What is the optimal dose and duration of salvage therapy using oral steroids? H. How long after SHL is transtympanic steroid therapy effective for salvage of initial treatment failures? Many trials have been published investigating the use of corticosteroids in patients with idiopathic sudden sensorineural hearing loss (ISSHNL); however, these trials adopted a variety of methodologies and drew varying conclusions. There is laboratory evidence of an inflammatory cell death cascade in ISSNHL, which is modified by steroid therapy. The term corticosteroid refers to common synthetic glucocorticoids delivered via the oral, intravenous, and/or intratympanic routes. These steroids include prednisone, methylprednisolone, solumedrol, and dexamethasone. Corticosteroids are known to have sites of action in the inner ear, with efficacy in viral, vascular, syphilitic, autoimmune, endolymphatic hydrops (Meniere disease), and other etiologies of hearing loss.1,2 Most studies, however, do not meet presentday criteria in terms of highest quality evidence, as identified by RCTs, systematic reviews, meta-analyses, or evidence reports. Systematic Reviews of Randomized Controlled Trials A Cochrane review, first published in 2006 and updated in 2009, found only 2 trials that met their inclusion criteria, and both were of low methodological quality and with small numbers of subjects.3 One trial showed a lack of effect of oral steroids compared with placebo, and one study showed a significant improvement in 61% of patients receiving corticosteroids compared with 32% in the control group (placebo and untreated patients). The authors concluded that the value of corticosteroid treatment for ISSNHL remained unclear due to the conflicting results of the studies.

In another systematic review, Conlin and Parnes (2007)4 found no valid RCTs to determine the effectiveness of corticosteroids in SSNHL and pointed out limitations in landmark studies that such treatment has been traditionally based on. In a separate treatment meta-analysis reviewing 5 studies that met their inclusion criteria, the same authors concluded that there was no evidence that corticosteroid treatment was better than a placebo.5 A recent meta-analysis of various medical treatments, including corticosteroids, showed a slight but not statistically significant improvement with medical therapy compared with placebo.6 Benefits vs Risks of Oral Corticosteroid Therapy for Individual Patients On the basis of the studies cited above, the clinician might choose not to prescribe corticosteroids for ISSNHL. However, faced with a patient with the serious consequences of a severe to profound SSNHL, corticosteroid treatment is one of the few treatment options that has data showing efficacy, although even those data are somewhat equivocal.7-16 The greatest spontaneous improvement in hearing occurs during the first 2 weeks17; late recovery has been reported but is a rare event. In a similar fashion, treatment with corticosteroids appears to offer the greatest recovery in the first 2 weeks, with little benefit after 4 to 6 weeks.7,15,18-20, 21-25 For maximal treatment outcomes, recommended treatment doses of oral prednisone are given at 1 mg/kg/d in a single (not divided) dose, with the usual maximum dose of 60 mg daily, and treatment duration of 10 to 14 days.26 Data comparing treatment protocols are limited, but one representative regimen uses the maximum dose for 4 days, followed by a 10-mg taper every 2 days.18 The basis of selecting this dose rests on the maximum adrenal output of hydrocortisone (cortisol) of 200 to 300 mg/d during stress. Prednisone is 4 times, methylprednisolone is 5 times, and dexamethasone is 25 times more powerful than hydrocortisone. The equivalent dose of prednisone 60 mg is 48 mg for methylprednisolone and 10 mg for dexamethasone. Underdosage, by the above standards, is a possibility if attention is not given to these ratios. For example, the commonly prescribed methylprednisolone dose pack, which contains 4-mg tablets, provides 6 tablets the first day and 1 less on each subsequent day, for a total dose of 84 mg over 6 days.27 This only gives the equivalent of 105 mg prednisone, compared with a total dose of 540 mg prednisone over 14 days for a 60-kg adult using the formula above. As noted above, early treatment is important, so the clinician should ensure that the patient is initially adequately dosed. Potential side effects of systemic corticosteroid therapy are reported in many organ systems. Corticosteroids are hormones and have access to, as well as an effect on, all organ systems. The commonly used glucocorticoids, such as prednisone, have little mineralocorticoid, androgenic, or estrogenic effect, and the major systemic side effects are suppression of hypothalamic-pituitaryadrenal function and signs and symptoms of Cushing syndrome.28 Some common side effects of prednisone include insomnia, dizziness, weight gain, increased sweating, gastritis,mood changes, photosensitivity, and hyperglycemia. Severe (but rare) side effects include pancreatitis, bleeding, hypertension, cataracts, myopathy, opportunistic infections, osteoporosis, and osteonecrosis manifesting as fractures and aseptic necrosis of the femoral and humeral heads.27-31 To minimize the risk of treatment, patients with systemic medical conditions such as insulindependent or poorly controlled diabetes, labile hypertension, tuberculosis, peptic ulcer disease, and prior psychiatric reactions to corticosteroids, among others, may not be able to receive systemic corticosteroids. The lack of clear evidence supporting this treatment, as well as the existence of potential adverse treatment effects, supports a large role for shared decision making with patients.32 Most serious side effects, however, occur with chronic use, and adverse events are usually acceptable and manageable for the short 10- to 14-day course of steroids recommended for SSNHL. Alexander et al33 reviewed the safety of high-dose steroids taken for up to 22 weeks for autoimmune inner ear disease and found that most patients completed the course, with the most frequent adverse events being hyperglycemia and weight gain. There is also evidence that osteonecrosis and fractures occur more commonly in patients with preexisting bone or joint problems in conditions such as systemic lupus erythematosis and rheumatoid arthritis.34 Intratympanic Corticosteroids A more recent method of corticosteroid delivery is the intratympanic (IT) route. The use of IT corticosteroids in patients who do not recover with systemic corticosteroids ( salvage therapy ); IT corticosteroids will be reviewed here in the context of initial treatment. Parnes et al22 published the first animal data and clinical series and demonstrated higher inner ear steroid levels following IT steroid application, with benefit in one-third of patients, and higher percentages of benefit in certain otologic conditions. Subsequent laboratory data have substantiated the claim of higher perilymph steroid concentrations after IT steroid application.35 Since those publications, a large number of small series without controls, and usually retrospective in nature, have shown inconsistent results for IT steroids. One regimen of initial treatment combining oral and IT steroids for patients with profound hearing loss, in an effort to improve the poor prognosis, had a positive effect in only 3 of 25 patients.36 However, a combination of a high-dose prednisone taper with IT steroids resulted in partial or complete hearing recovery in 14 of 16 patients.37 Another study combining oral and IT corticosteroids did not show a difference in hearing recovery compared with corticosteroids alone.38 A recent study proposed IT treatment as the sole initial treatment.39 The protocol consisted of early injections for 3 consecutive days, with only 3 of 34 patients failing to improve. A systematic review concluded that IT steroids can be a valuable solution for patients with ISSNHL who either cannot tolerate systemic steroid therapy or are refractory to it.40 For patients with diabetes who cannot take systemic corticosteroids, IT steroids may be an alternative.41,42 Intratympanic steroids are usually administered as either dexamethasone or solumedrol.22 Agents such as histamine and hyaluronic acid have been shown to facilitate transport ofthe corticosteroid across the round window membrane in laboratory studies.43,44 Intratympanic corticosteroids appear to affect both immune suppression and ion homeostasis.45 Corticosteroid concentrations vary widely between studies; most studies on IT corticosteroids refer to dexamethasone 10 to 24 mg/mL and solumedrol 30 mg/mL and higher. Higher concentrations appear to have better outcomes. The frequency of IT steroid administration also varies widely between studies, from self-administration by the patient across a pressure-equalizing tube (PET) several times per day to physician administered for several consecutive days to once weekly or less. Moreover, IT corticosteroids have been reported as primary, secondary, or salvage treatment. As such, the myriad studies on IT steroids are difficult to assess, but based on reasonable success in initial reports, more rigorous studies are indicated.8,45-49 Although with less potential toxicity than systemic corticosteroid treatment, IT corticosteroids can also have adverse effects. These are infrequent but include pain, transient dizziness, infection, persistent tympanic membrane perforation, possible vasovagal or syncopal episode during injection, cost, and multiple office visits. The only RCT on oral vs IT steroid therapy for ISSNHL was conducted at 16 centers and enrolled 250 patients.50 All patients were enrolled within 14 days of onset of their SSNHL. For primary therapy of SSNHL, promptly administered and equivalently dosed oral and IT steroid appeared to be equally effective, with hearing improvement seen in more than 75% of treated patients. Because the hearing outcomes in these 2 groups of patients were equivalent, the clinician s judgment about the choice of therapy can and should be based on other considerations, such as risk of side effects and cost. Adverse effects were reported by 88% of the oral group, such as elevated blood sugar, increased thirst, and sleep or appetite changes, and 90% of the IT group, such as transient pain at the injection site and brief caloric vertigo. The adverse effects were the anticipated manageable side effects, most of which were resolved within 1 to 2 weeks, with rare outlying persistent tympanic membrane perforations lasting up to 6 months. Harm vs Benefit of Corticosteroid Therapy Despite the uncertain balance of benefit vs harm for steroid therapy based on existing RCTs, there is also insufficient evidence to conclude the treatment is ineffective. Moreover, a large volume of observational studies suggests a treatment benefit, although to what degree this exceeds spontaneous resolution is not known.8 Considering the devastation of SSNHL and the profound impact on QOL that a hearing improvement may offer, the AAo-HNSF guideline panels concluded that, therefore, even a small possibility of hearing improvement makes this a reasonable treatment to offer to patients. Intratympanic (IT) steroids For patients who fail to recover spontaneously or after initial management, including corticosteroid treatment and/or observation, IT delivery of steroids has been proposed by a number of authors as an option to obtain additional hearing recovery.8,22,35,36,51-54 There is now a significant body of research investigating the use of IT steroid therapy in this setting, consisting of numerous case series and 4 RCTs. Although most of these studies sufferfrom considerable design flaws, the majority do show improved hearing outcomes after IT steroid therapy.40 Similar to the concept of parenteral steroids for ISSNHL, IT steroid therapy aims to reduce inflammation in the inner ear that may be contributing to or preventing recovery from hearing loss. There is experimental evidence from animal models indicating that a considerably higher concentration of steroid can be delivered to the inner ear when the medication is delivered through a transtympanic route compared with systemic administration.22,35 The steroids are delivered to the middle ear and then absorbed and diffused through the round window membrane into the inner ear. Intratympanic steroids may be delivered via a needle through the tympanic membrane or may be placed into the middle ear through a tympanostomy tube or a myringotomy (incision in the eardrum). Steroids may also be delivered to the round window via a microcatheter, a MicroWick,51 hydrogel applications, and nanoparticles. Transtympanic needle or tympanostomy tubes are the most frequently used.2 The IT delivery route has the additional benefit of avoiding the considerable side effects of further systemic steroid therapy. Intratympanic steroids very rarely cause changes in serum glucose levels in patients with diabetes.41 They may also be given to patients with cataracts, myasthenia gravis, and glaucoma.23 The principal risk appears to be a persistent tympanic membrane perforation at the injection site. This complication, however, is rare and frequently resolves spontaneously or with a paper patch myringoplasty in the office. Existing studies showed considerable variability in the dose and concentration of steroids administered; the timing, frequency, and total number of injections (ranging from one to several to continuous); and drug selection (dexamethasone and methylprednisolone).40 This high degree of variability makes it difficult to compare results across studies. Despite this variability, 3 of the 4 RCTs evaluating intratympanic steroids as salvage therapy found that IT steroids improved hearing outcomes beyond placebo. Hearing improvement occurred in 53% to 90% of patients.53,54 The other RCT compared a continuous infusion of steroids to the middle ear for 14 days with an infusion of saline.55 This study, with only 23 patients, was underpowered to detect meaningful differences, and all patients in the control group received IT steroids after 1 week, making it impossible to differentiate longer term differences. This study failed to find a statistically significant difference in improvement in PTA between the treatment and placebo groups (mean [SD], 13.9 [21.3] dB HL vs 5.4 [10.4] dB HL, respectively; P = .07), although word recognition trended toward better in the treatment group (24.4% improvement in one group vs 4.5% in the other group; P = .07). The majority of non-RCTs and noncontrolled trials of IT steroids as salvage therapy reported a hearing improvement in the treatment group ranging from 8% to 100%.8,38,40,42,56-60 One critical problem in the individual trials is how an improvement in hearing was defined. Most authors used a 10-dB HL improvement in the PTA or an improvement in WRS of 15% or 20% as indicative of successful treatment. Others used a 30-dB HL PTA improvement or 50% recovery as the definition of successful therapy. Depending on the degree of hearing loss, these thresholds may or may not indicate an improvement to useable hearing. Hence, these outcomes, although statistically significant, may not be of clinical significance.Despite the limitations of the existing research, the majority of studies evaluating IT steroids as salvage therapy for ISSNHL, including both nonrandomized and RCTs, demonstrated a consistent benefit of some degree of additional hearing recovery beyond that afforded by initial therapy. Because salvage IT steroid therapy has been found to be beneficial for some degree of hearing recovery, treatment may be applicable for those who have persistent hearing loss despite conventional treatment with oral or intravenous steroids. The decision to perform this treatment should be based on whether a significant degree of hearing loss still exists and patient preference. The decision to treat is often subjective but should take into consideration the risks and benefits of the treatment being considered. Q2. What is the efficacy of hyperbaric oxygen therapy for SHL? Vascular compromise and associated cochlear ischemia are thought to be contributory to SSNHL in some cases or could be a final common pathway to hearing loss. Hyperbaric oxygen therapy exposes a patient to 100% oxygen at a pressure level higher than 1 atmosphere absolute (ATA) in a specially designed sealed chamber. This allows for delivery of greatly increased partial pressure of oxygen to the tissues in this case the cochlea, which is very sensitive to ischemia. Furthermore, HBOT is thought to have complex effects on immunity, oxygen transport, and hemodynamics, reducing hypoxia and edema and potentiating normal host responses to infection and ischemia.61 Hyperbaric oxygen therapy has been implemented for the treatment of ISSNHL, typically as an adjunctive treatment. The most recent Cochrane review on this topic reports that HBOT was first used to treat SHL in the late 1960s by French and German workers.62 Since that time, numerous studies (n = 91) have reported or evaluated the use of HBOT in SHL, but only a small fraction are prospective RCTs. Two important issues to consider in the evaluation of potential treatments are the outcome measures used to assess benefit and the risk of adverse events. Evaluation of outcome is particularly challenging for ISSNHL, as there is no widely accepted standard, and each method of measuring outcome has limitations.63 The Cochrane review included 7 identified RCTs, published between 1985 and 2004.64-70 The criterion used for determination of significant benefit was 50% improvement in hearing. Although the chance of a 50% improvement was not significantly increased following HBOT, the chance of a 25% increase was. Data indicated that a physician would need to treat 5 patients with HBOT therapy to improve 1 person s hearing by 25%. Whether this is truly clinically significant is debatable. Although the small total numbers of subjects in this pooled group (n = 392) precluded extensive subgroup analysis, data suggested that improvement may be related to the severity of the hearing loss on presentation. Results were better if HBOT was performed within 2 weeks of acute onset. However, both of these issues should be explored further in future RCTs.Since this review, the panel found only one other prospective RCT of HBOT for SSNHL.71 Thirty-six patients were randomized into the study arm that consisted of HBOT plus

standard medical therapy with prednisolone and compared them with 21 patients who were treated only with prednisolone. Success was defined as hearing regained completely ( 50-dB improvement) or moderately (10- to 50-dB improvement). Seventy-nine percent of patients in the HBOT arm had success compared with 71.3% of the control group, a nonsignificant difference. The study offers no evidence that would support the addition of HBOT to a medical regimen for the treatment of SSNHL. Although risk of serious side effects with HBOT is small, some risks do exist. These include damage to ears, sinuses, and lungs from pressure changes; temporary worsening of short-sightedness; claustrophobia; and oxygen poisoning. Major adverse events were not reported in most of the studies reviewed. In a population of 782 patients with 11,376 sessions receiving HBOT for a variety of indications, the primary complication of HBOT was difficultly equalizing pressure in the middle ear, which occurred in 17% of patients.72 Another study found that 45% of patients undergoing HBOT for a variety of indications had eustachian tube dysfunction.73 Patients undergoing HBOT for SSNHL may have fewer complications as the use of concurrent systemic steroids is common and may decrease the inflammation or edema that may lead to difficulty in pressure equalization or eustachian tube dysfunction. In a study of 80 patients undergoing HBOT for SSNHL, 5 (6.25%) had ear or sinus barotrauma.74 In addition, patients may suffer from some degree of confinement anxiety while undergoing HBOT.72,74 Finally, HBOT is an expensive and time-consuming intervention. Therapy typically involves multiple 1- to 2-hour sessions over days to weeks. Although costs may vary considerably among facilities, queries by the AA)-HNSF guideline panel showed that typical fees in academic institutions are approximately $600 to $700 per session, including both technical and professional fees. Typical treatments have consisted of 5 to 10 sessions. Given the small number of patients in the trials reviewed, methodological shortcomings, and poor reporting, the reported findings of benefit should be interpreted cautiously. The substantial cost, the potential adverse effects (including barotrauma), a question of the clinical significance of reported benefits, and the confounding effect of cointerventions (steroids, antivirals, rheologic agents) make it difficult to weigh benefits and harms. The evidence supports possible benefit of HBOT as an adjuvant treatment in cases of acute SSNHL when used within 3 months of the onset of the hearing loss, with potentially more benefit noted in cases of severe to profound loss.

References

1. Norris CH. Drugs affecting the inner ear: a review of their clinical efficacy, mechanisms of action, toxicity, and place in therapy. Drugs. 1988;36(6):754-772.
2. McCall AA, Swan EE, Borenstein JT, Sewell WF, Kujawa SG, McKenna MJ. Drug delivery for treatment of inner ear disease: current state of knowledge. Ear Hear. 2010;31(2):156-165.
3. Wei BP, Mubiru S, O Leary S. Steroids for idiopathic sudden sensorineural hearing loss. Cochrane Database Syst Rev. 2006;(1):CD003998.
4. Conlin AE, Parnes LS. Treatment of sudden sensorineural hearing loss, I: a systematic review. Arch Otolaryngol Head Neck Surg. 2007;133(6):573-581.
5. Conlin AE, Parnes LS. Treatment of sudden sensorineural hearing loss, II: a meta-analysis. Arch Otolaryngol Head Neck Surg. 2007;133(6):582-586.
6. Labus J, Breil J, Stutzer H, Michel O. Meta-analysis for the effect of medical therapy vs. placebo on recovery of idiopathic sudden hearing loss. Laryngoscope. 2010;120(9):1863-1871.
7. Byl FM. Seventy-six cases of presumed sudden hearing loss occurring in 1973: prognosis and incidence. Laryngoscope. 1977;87(5, pt 1):817-825.
8. Haynes DS, O Malley M, Cohen S, Watford K, Labadie RF. Intratympanic dexamethasone for sudden sensorineural hearing loss after failure of systemic therapy. Laryngoscope. 2007;117(1):3-15.
9. Haberkamp TJ, Tanyeri HM. Management of idiopathic sudden sensorineural hearing loss. Am J Otol. 1999;20(5):587-592; discussion 593-595. 10. Wilson WR, Byl FM, Laird N. The efficacy of steroids in the treatment of idiopathic sudden hearing loss: a double-blind clinical study. Arch Otolaryngol. 1980;106(12):772-776. 11. Moskowitz D, Lee KJ, Smith HW. Steroid use in idiopathic sudden sensorineural hearing loss. Laryngoscope. 1984;94(5, pt 1):664-666. 12. Stokroos RJ, Albers FW. Therapy of idiopathic sudden sensorineural hearing loss: a review of the literature. Acta Otorhinolaryngol Belg. 1996;50(1):77-84. 13. Chen CY, Halpin C, Rauch SD. Oral steroid treatment of sudden sensorineural hearing loss: a ten year retrospective analysis. Otol Neurotol. 2003;24(5):728-733. 14. Ghosh A, Jackson R. Best evidence topic report: steroids in sudden sensorineural hearing loss. Emerg Med J. 2005;22(10):732-733. 15. Slattery WH, Fisher LM, Iqbal Z, Friedman RA, Liu N. Intratympanic steroid injection for treatment of idiopathic sudden hearing loss. Otolaryngol Head Neck Surg. 2005;133(2):251- 259. 16. Jeyakumar A, Francis D, Doerr T. Treatment of idiopathic sudden sensorineural hearing loss. Acta Otolaryngol. 2006;126(7):708-713. 17. Mattox DE, Simmons FB. Natural history of sudden sensorineural hearing loss. Ann Otol Rhinol Laryngol. 1977;86(4, pt 1):463-480. 18. Rauch SD. Clinical practice: idiopathic sudden sensorineural hearing loss. N Engl J Med. 2008;359(8):833-840. 19. Fetterman BL, Saunders JE, Luxford WM. Prognosis and treatment of sudden sensorineural hearing loss. Am J Otol. 1996;17(4):529-536. 20. Narozny W, Kuczkowski J, Mikaszewski B. Steroids promote recovery in sudden hearing loss. Otolaryngol Head Neck Surg. 2006;134(6):1068. 21. Megighian D, Bolzan M, Barion U, Nicolai P. Epidemiological considerations in sudden hearing loss: a study of 183 cases. Arch Otorhinolaryngol. 1986;243(4):250-253. 22. Parnes LS, Sun AH, Freeman DJ. Corticosteroid pharmacokinetics in the inner ear fluids: an animal study followed by clinical application. Laryngoscope. 1999;109(7, pt 2):1-17. 23. Banerjee A, Parnes LS. Intratympanic corticosteroids for sudden idiopathic sensorineural hearing loss. Otol Neurotol. 2005;26(5):878-881. 24. Fitzgerald DC, McGuire JF. Intratympanic steroids for idiopathic sudden sensorineural hearing loss. Ann Otol Rhinol Laryngol.2007;116(4):253-256. 25. Cvorovic L, Deric D, Probst R, Hegemann S. Prognostic model for predicting hearing recovery in idiopathic sudden sensorineural hearing loss. Otol Neurotol. 2008;29(4):464- 469. 26. Powell-Tuck J, Bown RL, Lennard-Jones JE. A comparison of oral prednisolone given as single or multiple daily doses for active proctocolitis. Scand J Gastroenterol. 1978;13(7):833-837. 27. UpToDate, Inc. Methylprednisolone: drug information. http://www.uptodate.com/contents/methylprednisolone-drug-information. Accessed May 15, 2011. 28. Saag KG, Furst DE. Major side effects of systemic glucocorticords. http://www.uptodate.com/contents/major-side-effectsof- systemic-glucocorticoids?source=search_result&selected Title=1~150. Accessed May 18, 2011. 29. Drugs.com. MethylPREDNISolone Dose Pack. http://www.drugs.com/mtm/methylprednisolone-dose-pack.html. Accessed May 18, 2011. 30. Swartz SL, Dluhy RG. Corticosteroids: clinical pharmacology and therapeutic use. Drugs. 1978;16(3):238-255. 31. Holland EG, Taylor AT. Glucocorticoids in clinical practice. J Fam Pract. 1991;32(5):512-519. 32. Nash JJ, Nash AG, Leach ME, Poetker DM. Medical malpractice and corticosteroid use. Otolaryngol Head Neck Surg. 2011;144(1):10-15. 33. Alexander TH, Weisman MH, Derebery JM, et al. Safety of high-dose corticosteroids for the treatment of autoimmune inner ear disease. Otol Neurotol. 2009;30(4):443-448. 34. McDonough AK, Curtis JR, Saag KG. The epidemiology of glucocorticoid-associated adverse events. Curr Opin Rheumatol. 2008;20(2):131-137. 35. Chandrasekhar SS. Intratympanic dexamethasone for sudden sensorineural hearing loss: clinical and laboratory evaluation. Otol Neurotol. 2001;22(1):18-23. 36. Battista RA. Intratympanic dexamethasone for profound idiopathic sudden sensorineural hearing loss. Otolaryngol Head Neck Surg. 2005;132(6):902-905. 37. Battaglia A, Burchette R, Cueva R. Combination therapy (intratympanic dexamethasone + high-dose prednisone taper) for the treatment of idiopathic sudden sensorineural hearing loss. Otol Neurotol. 2008;29(4):453-460. 38. Ahn JH, Yoo MH, Yoon TH, Chung JW. Can intratympanic dexamethasone added to systemic steroids improve hearing outcome in patients with sudden deafness? Laryngoscope. 2008;118(2):279-282. 39. Filipo R, Covelli E, Balsamo G, Attanasio G. Intratympanic prednisolone therapy for sudden sensorineural hearing loss: a new protocol. Acta Otolaryngol. 2010;130(11):1209-1213. 40. Seggas I, Koltsidopoulos P, Bibas A, Tzonou A, Sismanis A. Intratympanic steroid therapy for sudden hearing loss: a review of the literature. Otol Neurotol. 2011;32(1):29-35. 41. Kakehata S, Sasaki A, Oji K, et al. Comparison of intratympanic and intravenous dexamethasone treatment on sudden sensorineural hearing loss with diabetes. Otol Neurotol. 2006;27(5):604-608. 42. Han CS, Park JR, Boo SH, et al. Clinical efficacy of initial intratympanic steroid treatment on sudden sensorineural hearing loss with diabetes. Otolaryngol Head Neck Surg. 2009;141(5):572-578. 43. Chandrasekhar SS, Rubinstein RY, Kwartler JA, et al. Dexamethasone pharmacokinetics in the inner ear: comparison of route of administration and use of facilitating agents. Otolaryngol Head Neck Surg. 2000;122(4):521-528. 44. Borden RC, Saunders JE, Berryhill WE, Krempl GA, Thompson DM, Queimado L. Hyaluronic acid hydrogel sustains the delivery of dexamethasone across the round window membrane. Audiol Neurootol. 2011;16(1):1-11. 45. Hamid M, Trune D. Issues, indications, and controversies regarding intratympanic steroid perfusion. Curr Opin Otolaryngol Head Neck Surg. 2008;16(5):434-440. 46. Hu A, Parnes LS. Intratympanic steroids for inner ear disorders: a review. Audiol Neurootol. 2009;14(6):373-382. 47. Doyle KJ, Bauch C, Battista R, et al. Intratympanic steroid treatment: a review. Otol Neurotol. 2004;25(6):1034-1039. 48. Alles MJ, der Gaag MA, Stokroos RJ. Intratympanic steroid therapy for inner ear diseases, a review of the literature. Eur Arch Otorhinolaryngol. 2006;263(9):791-797. 49. Hoffer ME, Balough BJ, Gottshall KR. Delivery of drugs to the inner ear. Curr Opin Otolaryngol Head Neck Surg. 2006;14(5):329-331. 50. Rauch SD, Halpin CF, Antonelli PJ, et al. Oral vs intratympanic corticosteroid therapy for idiopathic sudden sensorineural hearing loss: a randomized trial. JAMA. 2011;305(20):2071-2079. 51. Silverstein H, Jackson LE, Rosenberg SI. Silverstein Microwick

for treatment of inner ear disease. Oper Techn Otolaryngol Head Neck Surg. 2001;12(3):144-147. 52. Ahn JH, Han MW, Kim JH, Chung JW, Yoon TH. Therapeutic effectiveness over time of intratympanic dexamethasone as salvage treatment of sudden deafness. Acta Otolaryngol. 2008;128(2):128-131. 53. Ho HG, Lin HC, Shu MT, Yang CC, Tsai HT. Effectiveness of intratympanic dexamethasone injection in sudden-deafness patients as salvage treatment. Laryngoscope. 2004;114(7):1184-1189. 54. Xenellis J, Papadimitriou N, Nikolopoulos T, et al. Intratympanic steroid treatment in idiopathic sudden sensorineural hearing loss: a control study. Otolaryngol Head Neck Surg. 2006;134(6):940-945. 55. Plontke SK, Lowenheim H, Mertens J, et al. Randomized, double blind, placebo controlled trial on the safety and efficacy of continuous intratympanic dexamethasone delivered via a round window catheter for severe to profound sudden idiopathic sensorineural hearing loss after failure of systemic therapy. Laryngoscope. 2009;119(2):359-369. 56. Van Wijck F, Staecker H, Lefebvre PP. Topical steroid therapy using the Silverstein Microwick in sudden sensorineural hearing loss after failure of conventional treatment. Acta Otolaryngol. 2007;127(10):1012-1017. 57. Plontke S, Lowenheim H, Preyer S, et al. Outcomes research analysis of continuous intratympanic glucocorticoid delivery in patients with acute severe to profound hearing loss: basis for planning randomized controlled trials. Acta Otolaryngol. 2005;125(8):830-839. 58. Lee HS, Kim JM, Kim YJ, Chung DH, Seo BS, Kim SH. Results of intratympanic dexamethasone injection as salvage treatment in idiopathic sudden hearing loss. J Otolaryngol Head Neck Surg. 2008;37(2):263-268. 59. Kilic R, Safak MA, Oguz H, et al. Intratympanic methylprednisolone for sudden sensorineural hearing loss. Otol Neurotol. 2007;28(3):312-316. 60. Dallan I, De Vito A, Fattori B, et al. Intratympanic methylprednisolone in refractory sudden hearing loss: a 27-patient case series with univariate and multivariate analysis. Otol Neurotol. 2010;31(1):25-30. 61. Gill AL, Bell CN. Hyperbaric oxygen: its uses, mechanisms of action and outcomes. QJM. 2004;97(7):385-395. 62. Bennett MH, Kertesz T, Yeung P. Hyperbaric oxygen for idiopathic sudden sensorineural hearing loss and tinnitus. Cochrane Database Syst Rev. 2007;(1):CD004739. 63. Halpin C, Rauch SD. Using audiometric thresholds and word recognition in a treatment study. Otol Neurotol. 2006;27(1):110-116. 64. Cavallazzi G, Pignataro L, Capaccio P. Italian experience in hyperbaric oxygen therapy for idiopathic sudden sensorineural hearing loss. Paper presented at: International Joint Meeting on Hyperbaric and Underwater Medicine; September 5-8, 1996; Milan, Italy. 65. Fattori B, Berrettini S, Casani A, Nacci A, De Vito A, De Iaco G. Sudden hypoacusis treated with hyperbaric oxygen therapy: a controlled study. Ear Nose Throat J. 2001;80(9):655-660. 66. Hoffman G, Bohmar D, Desloovere C. Hyperbaric oxygenation as a treatment of chronic forms of inner ear hearing loss and tinnitus. In: Proceedings of the Eleventh International Congress on Hyperbaric Medicine. Flagstaff, AZ: Best Publishing; 1995. 67. Hoffmann G, Bohmer D, Desloovere C. Hyperbaric oxygenation as a treatment for sudden deafness and acute tinnitus. In: Proceedings of the Eleventh International Congress on Hyperbaric Medicine. Flagstaff, AZ: Best Publishing; 1995. 68. Pilgramm M, Lamm H, Schumann K. Hyperbaric oxygen therapy in sudden deafness [in German]. Laryngol Rhinol Otol (Stuttg). 1985;64(7):351-354. 69. Schwab B, Flunkert C, Heermann R, Lenarz T. HBO in the therapy of cochlear dysfunctions: first results of a randomized study. In: EUBS Diving and Hyperbaric Medicine, Collected Manuscripts of XXIV Annual Scientific Meeting of the European Underwater and Baromedical Society. Stockholm: EUBS; 1998. 70. Topuz E, Yigit O, Cinar U, Seven H. Should hyperbaric oxygen be added to treatment in idiopathic sudden sensorineural hearing loss? Eur Arch Otorhinolaryngol. 2004;261(7):393-396. 71. Cekin E, Cincik H, Ulubil SA, Gungor A. Effectiveness of hyperbaric oxygen therapy in management of sudden hearing loss. J Laryngol Otol. 2009;123(6):609-612. 72. Plafki C, Peters P, Almeling M, Welslau W, Busch R. Complications and side effects of hyperbaric oxygen therapy. Aviat Space Environ Med. 2000;71(2):119-124. 73. Fernau JL, Hirsch BE, Derkay C, Ramasastry S, Schaefer SE. Hyperbaric oxygen therapy: effect on middle ear and Eustachian tube function. Laryngoscope. 1992;102(1):48-52. 74. Korpinar S, Alkan Z, Yigit O, et al. Factors influencing the outcome of idiopathic sudden sensorineural hearing loss treated with hyperbaric oxygen therapy. Eur Arch Otorhinolaryngol. 2011;268(1):41-47. 75. National Institute of Deafness and Communication Disorders. Sudden deafness. 2000. http://www.nidcd.nih.gov/health/hearing/sudden.htm. Accessed May 18, 2011. 76. Saunders JE, Luxford WM, Devgan KK, Fetterman BL. Sudden hearing loss in acoustic neuroma patients. Otolaryngol Head Neck Surg. 1995;113(1):23-31.

WHY THIS TOPIC IS IMPORTANT: Sudden hearing loss (SHL) is a frightening symptom that often prompts an urgent or emergent visit to a physician. Here we are duscussing sudden sensorineural hearing loss (SSNHL), one of many causes of SHL, which, if recognized and managed promptly, may improve hearing recovery and patient quality of life (QOL).

Sudden sensorineural hearing loss affects 5 to 20 per 100,000 population, with about 4000 new cases per year in the United States.7,17 The SSNHL definition used throughout this proposal is based on its consistent use in the literature and National Institute on Deafness and Other Communication Disorders (NIDCD) criteria75; however, the panel recognizes that in clinical practice, expanding the definition to cases with less than 30 dB of hearing loss may be considered. The panel recognizes that the NIDCD definition is not universally used, and accordingly, published evidence not using this definition was considered. The distinction between SSNHL and other causes of SHL is one that should be made by the initial treating health care provider, so that early diagnosis and management can be instituted. Moreover, nonidiopathic causes of SSNHL must be identified and addressed during the course of management; the most pressing of these are vestibular schwannoma (acoustic neuroma), stroke, and malignancy.76 Up to 90% of SSNHL, however, is idiopathic at presentation and is presumptively attributed to vascular, viral, or multiple etiologies.18 A maximum of 32% to 65% of cases of SSNHL may recover spontaneously.5,17 Clinical experience indicates that even this recovery rate may be an overestimation. Prognosis for recovery is dependent on a number of factors, including patient age, presence of vertigo at onset, degree of hearing loss, audiometric configuration, and time between onset of hearing loss and treatment.4,8,19 Treatment options are myriad and include systemic and topical steroids, antiviral agents, rheologic agents, diuretics, hyperbaric oxygen treatment, other medications, middle ear surgery for fistula repair, and observation alone. The comparative efficacy of these treatments, however, is not known, considering that the definitive etiology is also commonly not known.

The AAO-HNSF published a clinical practice guideline (CPG) on Sudden Hearing Loss in 2012. This CPG will need to be updated in 2017, therefore a systematic review would inform the update.

Please choose a description that best describes your role or perspective: (you may select more than one category if appropriate)

professional society

If you are you making a suggestion on behalf of an organization, please state the name of the organization

American Academy of Otolaryngology Head and Neck Surgery Foundation

Please tell us how you heard about the Effective Health Care Program