Objective. Sudden hearing loss (SHL) is a frightening symptom that often prompts an urgent or emergent visit to a physician. This guideline provides evidence-based recommendations for the diagnosis...

/pdf/clinical-practice-guideline-sudden-hearing-loss-8acwe9fo8a.pdf

Clinical practice guideline: sudden hearing loss.

Objective Autoimmune disease (e.g., Cogan syndrome) and other inflammatory inner ear diseases may ravage the labyrinth if not treated aggressively with antiinflammatory medication. Corticosteroids are the mainstay of treatment, yet, partly because of the existence of the blood-labyrinthine barrier, the ideal drug, dose, and route of administration are currently unknown. Study design In the present study, we established cochlear fluid pharmacokinetic profiles of hydrocortisone, methylprednisolone, and dexamethasone in the guinea pig following oral, intravenous, and topical (intratympanic) administration. High-performance liquid chromatography was used to determine the drug concentrations, and comparisons were made with simultaneous pharmacokinetic profiles from blood and cerebrospinal fluid. Results Our findings demonstrated a much higher penetration of all three drugs into the cochlear fluids following topical application as compared with systemic administration, with methylprednisolone showing the best profile. Discussion The results suggested that intratympanic administration of corticosteroids might be more efficacious while avoiding high blood levels and therefore the deleterious side effects of systemic use. Clinical application Thirty-seven patients with various inner ear disorders causing sensorineural hearing loss were subsequently treated using intratympanic corticosteroids, 20 with dexamethasone, and 17 with methlyprednisolone. Patients with immune-mediated hearing losses showed the best results, with notable improvement also seen in several cases of a "sudden deafness." No benefit was seen in patients with cochlear hydrops or those with sudden deterioration of a preexisting hearing loss. Three patients developed a transient otitis media related to the treatments, easily controlled with antibiotics. There were no cases of treatment-induced hearing loss and no permanent tympanic membrane perforations. Conclusions Overall injection of intratympanic corticosteroids for the treatment of hearing loss in inner ear disorders appears to be both safe and highly effective for certain disorders. The concept of this technique is supported by animal experimental data. The findings from the present study warrant further clinical application and experimental investigation.

Corticosteroid pharmacokinetics in the inner ear fluids: an animal study followed by clinical application.

Sudden sensorineural hearing loss (SSNHL) is commonly encountered in audiologic and otolaryngologic practice. SSNHL is most commonly defined as sensorineural hearing loss of 30dB or greater over at least three contiguous audiometric frequencies occurring within a 72-hr period. Although the differential for SSNHL is vast, for the majority of patients an etiologic factor is not identified. Treatment for SSNHL of known etiology is directed toward that agent, with poor hearing outcomes characteristic for discoverable etiologies that cause inner ear hair cell loss. Steroid therapy is the current mainstay of treatment of idiopathic SSNHL in the United States. The prognosis for hearing recovery for idiopathic SSNHL is dependent on a number of factors including the severity of hearing loss, age, presence of vertigo, and shape of the audiogram.

/pdf/sudden-sensorineural-hearing-loss-a-review-of-diagnosis-1y0qilepkr.pdf

Sudden sensorineural hearing loss: a review of diagnosis, treatment, and prognosis.

A healthy 58-year-old woman answers the telephone and realizes that her hearing is diminished on the left side. She notices aural fullness and loud tinnitus in the affected ear. Self-administered ear cleaning with the use of an over-the-counter kit does not relieve the symptoms. How should she be evaluated and treated?

http://otosurgery.org/2008_NEJM_RAUCH_SSNHL.pdf

Idiopathic Sudden Sensorineural Hearing Loss

Background
This is an update of a Cochrane review first published in The Cochrane Library in Issue 1, 2006 and previously updated in 2009.

Idiopathic sudden sensorineural hearing loss (ISSHL) is a clinical diagnosis characterised by a sudden deafness of cochlear or retrocochlear origin in the absence of a clear precipitating cause. Steroids are commonly prescribed to treat this condition. There is no consensus on their effectiveness.

Objectives
To determine whether steroids in the treatment of ISSHL a) improve hearing (primary) and b) reduce tinnitus (secondary).

To determine the incidence of significant side effects from the medication.

Search methods
We searched the Cochrane Ear, Nose and Throat Disorders Group Trials Register; the Cochrane Central Register of Controlled Trials (CENTRAL); PubMed; EMBASE; CINAHL; Web of Science; Cambridge Scientific Abstracts; ICTRP and additional sources for published and unpublished trials. The date of the most recent search was 22 April 2013.

Selection criteria
We identified all randomised controlled trials (with or without blinding) in which steroids were evaluated in comparison with either no treatment or a placebo. We considered trials including the use of steroids in combination with another treatment if the comparison control group also received the same other treatment. The two authors reviewed the full-text articles of all the retrieved trials of possible relevance and applied the inclusion criteria independently.

Data collection and analysis
We graded trials for risk of bias using the Cochrane approach. The data extraction was performed in a standardised manner by one author and rechecked by the other author. Where necessary we contacted investigators to obtain the missing information. Meta-analysis was neither possible nor considered appropriate because of the heterogeneity of the populations studied and the differences in steroid formulations, dosages and duration of treatment. We analysed and reported the quality of the results of each study individually. A narrative overview of the results is presented.

Main results
Only three trials, involving 267 participants, satisfied the inclusion criteria and all three studies were at high risk of bias. One trial showed a lack of effect of oral steroids in improving hearing compared with the placebo control group. The second trial showed a significant improvement of hearing in 61% of the patients receiving oral steroid and in only 32% of the patients from the control group (combination of placebo-treated group and untreated control group). The third trial also showed a lack of effect of oral steroids in improving hearing compared with the placebo control. However, this trial did not follow strict inclusion criteria for participant selection and analysis of data was limited by significant exclusion of participants from the final analysis and lack of participant compliance to the treatment protocol. No clear evidence was presented in two trials about any harmful side effects of the steroids. Only one study declared that no patients suffered from adverse effects of the steroid treatment.

Authors' conclusions
The value of steroids in the treatment of idiopathic sudden sensorineural hearing loss remains unclear since the evidence obtained from randomised controlled trials is contradictory in outcome, in part because the studies are based upon too small a number of patients.

Marc E. Guay

Papers

Sudden sensorineural hearing loss