It is agreed that sudden single-sided deafness is an emergency that is typically treated with corticosteroids. The question is, what route of treatment is best? Or, more specifically, is the intratympanic route as effective and fraught with fewer adverse effects than the time-honored systemic route?
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April 2006Investigators in an ongoing Phase III clinical trial, sponsored by the National Institutes of Health, hope to emerge with a definitive answer to this question. In separate phone interviews, one of the participating investigators and two other experts in sudden sensorineural hearing loss (SSNHL) discussed the importance and timeliness of the trial.
This is a well-known condition that all otolaryngologists learn about in residency, said Steven D. Rauch, MD, Associate Professor of Otology and Laryngology at Harvard Medical School in Boston, Mass. It’s one of the few otologic emergencies. The best epidemiologic data suggest it strikes one person per 5,000 per year. In metropolitan Boston, for example, this would mean that 300 or 400 people per year develop idiopathic SSNHL. It’s a fairly common problem.
I’m really excited that the trial has gone forward. We face this difficult problem all the time. – -Steven W. Cheung, MD
Untreated SSNHL has an ominous prognosis: in untreated patients, spontaneous recovery only occurs in 25% of cases; early diagnosis and treatment with corticosteroids improves the recovery rate to 50%.
For several reasons, idiopathic SSNHL is difficult to treat:
- The symptoms overlap with reversible nerve deafness due to such cases as drug-induced ototoxicity and acoustic trauma.
- Patients do not perceive the condition as urgent. The dilemma that we face is getting the patients in time to reverse the hearing loss, Dr. Rauch said. The predominant symptom is a stuffy ear. Ear wax, water, fluid, and infections can all cause stuffiness. The patient doesn’t connect it to nerve damage, and the hearing loss goes untreated or treated with pseudoepinephrine over the phone by a primary care physician. Often patients aren’t seen by an otolaryngologist for another month, when it’s far too late to treat the hearing loss. That’s frustrating to me. One of the things we hope to accomplish with our study would be to raise the awareness of this condition among primary care doctors.
- Even if patients are seen promptly, the chance of recovery with oral steroids is only 50%. When only 50% of patients respond, it may be that, with oral treatment, not enough gets to the ear, Dr. Rauch said.
Simple Test Identifies Emergencies
A physician or nurse can differentiate SSNHL from more benign causes of single-sided deafness by a simple test that can be given over the phone, Dr. Rauch said. If a patient calls and complains of blockage in one ear, ask the patient to hum, he said. Ask the patient where he hears his own voice when he hums. If he hears it in the blocked ear, there’s nothing to worry about. It’s a wax build-up or other benign cause. If the patient hears the humming in the good ear, it’s nerve loss and it’s an emergency. If nurses know that, we can find and treat SSNHL patients much more quickly. Sound goes toward a conductive hearing loss and away from a sensory hearing loss. It’s like a tuning fork test.
The Appeal of Intratympanic Injection
The investigators hope that the study will shine the light of science on intratympanic steroid injections, which are growing in popularity, Dr. Rauch said. The logic of treating by injecting directly into the ear has some appeal, but it is simplistic to think that if some is good, more is better, he said. Prior research has shown intratympanic steroid injections get approximately the same results as oral treatment.
Because intratympanic injections ought to be associated with fewer side effects than systemic therapy, investigators want to know if this treatment route is at least similar in efficacy and superior in safety to oral steroids. Therefore, the trial is designed to compare the routes of administration. We’ve gone to great lengths to make the treatments equivalent in duration and relative dose, Dr. Rauch said.
If a patient calls and complains of blockage in one ear, ask the patient to hum. If he hears it in the blocked ear, there’s nothing to worry about. If the patient hears the humming in the good ear, it’s nerve loss and it’s an emergency. – -Steven D. Rauch, MD
We’re monitoring the patients very closely during treatment and after. We want to know if there’s a difference in efficacy between the two treatments, and how the side effects compare. If one works much better than the other, it will become the favored treatment. If they work equally, the relative side effects will be important to consider. For example, the injections may be safer in a patient with brittle diabetes, but pills may be more appropriate in patients who are averse to needles.
Dr. Rauch expressed concern that some physicians may face financial temptations to overuse the injections because of the new reimbursement code for in-office injections. If you have a choice for writing a prednisone prescription or charging for an injection, you might feel the pressure to do the injection.
A Need for Controlled Studies
The investigators want to raise public awareness of idiopathic SSNHL and to scientifically identify the best treatment for it, he said. There is a moment in time in the evolution of a treatment, when it’s become widely known enough that people are adopting it, but it’s not entrenched as standard care, he said. We’re at or passing that tipping point. Most otolaryngologists are injecting steroids in people with various hearing loss, but we have no controlled studies to validate it, so it’s not yet an evidence-based treatment. The enthusiasm for it is growing wildly, and everyone’s getting paid for it. It may be that if we don’t get the evidence one way or the other, the insurance companies will shut it down.
The study is seen as a way to fill the dearth of scientific knowledge, he said, noting that the investigators are still recruiting patients. We want patients with idiopathic sudden deafness within two weeks of onset, he said, noting the challenge of catching patients within that window. The incidence of sudden hearing loss is pretty common, but the prevalence at any given moment is low. We can’t recruit effectively by putting up signs in buses. The only way we can recruit is by having other doctors send us patients.
The study is designed so that 250 patients, 125 in each study arm, will allow the investigators to make statistically significant analyses, Dr. Rauch said. The study is being conducted at eight centers that are listed on the Web site hosted by the NIH (see below). The investigators will follow the patients for six months, with assessments after one week of treatment, at the end of the two-week treatment period, and at two months and six months after enrollment into the study. Some of the parameters of the trial include the time course of the recovery, the stability of the recovery, and adverse events.
Experts Weigh In
Two experts not involved in the study discussed its importance and their hopes that it will provide some clarity to treatment for SSNHL. We don’t know what causes SSNHL and this has hampered our ability to develop effective treatments, said Stephen Cass, MD, Associate Professor of Otolaryngology at the University of Colorado School of Medicine in Denver.
Steroids have stood the test of time, but some people don’t tolerate steroids very well, he added. Therefore, we’ve seen more interest in targeting the ear more directly by placing medications into the ear. This approach has advantages, because we can get a high dose of steroids right to the ear with minimal side effects. Often oral medications don’t get to the ear very well, and the injection is relatively easy to do. The problem is, does the injection help the patient?
Dr. Cass agreed with Dr. Rauch that intratympanic injections have become something that is frequently performed without a lot of evidence to substantiate it. He said, We’ve had a lot of studies with no control group and no blinding. Results are difficult to interpret without those controls. That’s why it’s so important to do this kind of study. Studies like this reduce the guesswork and make us better doctors.
The only way of knowing with reasonable certainty is a large-scale study such as the one sponsored by the NIH, said Steven W. Cheung, MD, Associate Professor of Otolaryngology at the University of California-San Francisco. I’m really excited that the trial has gone forward. We face this difficult problem all the time. In some patients, particularly those with osteoporosis and diabetes, oral corticosteroids can cause complications, and an alternative would be very attractive, provided it would confer similar benefits to the oral route.
There have been anecdotal reports that the intratympanic method has been successful in restoring some level of hearing in patients who have not responded to oral steroids, he said. What is confusing is that some patients will recover hearing some time beyond the oral steroid dose. We don’t really know whether some of the patients treated with intratympanic steroids would have gotten better. This study is designed to that question, because there is a direct comparison between the two treatment modalities.
Both Drs. Cass and Cheung felt that the reimbursement issue may not create as much pressure to offer the intratympanic injection as Dr. Rauch feared. Reimbursement is an issue I hadn’t considered, Dr. Cheung said. My sense is that, overall, given the uncommon nature of the problem, the generation of revenue is an unlikely motive for choosing intratympanic steroids. It can’t possibly constitute enough of a revenue stream.
I think the strongest influence toward offering intratympanic injections is wanting the best for the patients and also wanting to be on the cutting edge, said Dr. Cass.
©2006 The Triological Society