There are a variety of causes of SSNHL.
A panel discussed this new research and provided context for the new clinical care guidelines for SSNHL in a session here at the AAO-HNS Annual Meeting.
Previous research has found that patients with AIED who are steroid resistant have higher levels of plasma interleukin-1 beta (IL-1B) than those who respond to steroids and that the IL-1 receptor antagonist anakinra can suppress its release. Andrea Vambutas, MD, chair of otolaryngology at Long Island Jewish Medical Center and North Shore University Hospital in New York, hopes that recent findings on patients with AIED are also found to be true for patients with SSNHL.
In a new study, Dr. Vambutas and her colleagues treated patients with AIED who had a decline in hearing with corticosteroids for 30 days. Those who didn’t respond were treated with anakinra therapy for 84 days. Phase I/II trial results show that the anakinra-treated steroid-resistant patients had audiometric improvement when compared with standard therapy (J Clin Invest. 2014;124:4115-4122).
“Sudden sensorineural hearing loss and autoimmune inner ear disease may have similar immunologic responses to disparate antigens,” Dr. Vambutas said. “I’m hoping that what we saw in autoimmune inner ear disease will translate to sudden sensorineural hearing loss, because it’s clearly a much larger population that needs to be served.”
That study stemmed from previous work demonstrating increased circulating IL-1beta in patients with steroid-resistant immune-mediated hearing loss.
Her laboratory has observed that steroid-sensitive, immune-mediated hearing loss is associated with an in vitro reduction of tumor necrosis factor (TNF) release in response to steroids in patients who are clinically responsive to corticosteroids (Arch Otolaryngol Head Neck Surg. 2012;138:1052-1058). Similarly, the antioxidant L-N-acetyl cysteine (LNAC) also can block the release of TNF. This finding helped explain earlier findings that steroids combined with LNAC produced twice as many patients with total hearing recovery than those just taking steroids (Acta Otolaryngol. 2012;132:369-376; Arch Otolaryngol Head Neck Surg. 2012;138:1052-1058).
Sudden Hearing Loss Guidelines
Panelists also discussed the guidelines for clinical care of sudden hearing loss, published by the AAO-HNS in 2012 (Otolaryngol Head Neck Surg. 2012;146(3 Suppl):S1-S35.)
James Saunders, MD, associate professor of otology/neurotology at the Geisel School of Medicine at Dartmouth in New Hampshire, said SSNHL still leaves a lot to be desired when it comes to evidence. “It still continues to be something that’s identified as a gap in knowledge in our membership,” he said.
One of his top take-home messages, he said, was that all patients should be evaluated for retrocochlear pathology. “That doesn’t necessarily mean that all patients should get an MRI scan, although in my practice, I strongly advise most patients to get an MRI scan,” he added.
His bottom line regarding SSNHL is that there are a variety of causes and that these possible causes aren’t necessarily mutually exclusive. “Perhaps what we’re really dealing with is some sort of a trigger that provokes it, perhaps vascular or viral, and that sets in motion a common cellular-stress pathway within the hair cells that results in cellular death,” he said.
Sujana Chandrasekhar, MD, director of New York Otology and a member of the guideline panel, said that, despite what might be a prevailing view in the field, steroids are not a true gold standard for SSNHL. The guidelines suggest that a clinician “may offer” steroids as an initial treatment.
“That was a surprising finding based on the literature,” Dr. Chandrasekhar said. “Most of us went into the guidelines panel thinking that steroid is, quote unquote, the gold standard for sudden hearing loss management.”
Actually, though, while some studies have found a benefit, others have not. A Cochrane review of the best available evidence found mixed results with steroids, she said. Three studies made the cut for the review, but all had a high risk of bias. So, in the end, she said, steroids are an option, not a recommendation.
Oral v. Intratympanic Administration
When it comes to oral administration versus intratympanic (IT) injection of steroids, the best guidance might come from a landmark 2011 study that found no benefit difference but a “less worrisome” side effect profile for IT injection (JAMA. 2011;305:2071-2079).
Contrary to the administration of steroids (systemic or IT) as an option for initial treatment, however, is the clinical practice guideline panel’s recommendation that physicians offer IT steroid injection as salvage if the patient fails any type of initial management, which might include observation, systemic or IT steroids, hyperbaric oxygen, or other treatment. “The literature on utility of IT steroid injections for salvage is actually very clear and shows a benefit,” she said.
Still, there might be a benefit to using IT injection in addition to systemic steroids, because delivery time is longer with IT injection if the round window is closed because of fibrous adhesions, Dr. Chandrasekhar said.
Seth Schwartz, MD, MPH, chair of the AAO’s Guidelines Task Force, discussed the guideline that clinicians “may offer hyperbaric oxygen therapy,” in which pure oxygen is delivered at a higher-than-usual pressure. While the treatment is not approved for SSNHL in the United States, international literature shows some possible promise. A Cochrane Review, for example, found improvement in acute idiopathic SSNHL but with the clinical significance unclear and no benefit in chronic idiopathic SSNHL.
“I’ve had more and more patients come into my clinic since the guidelines came out asking about this therapy,” said Dr. Schwartz, “and I think there’s a lot of uncertainty about who exactly we should recommend it to and how we should handle it. And we’re currently trying to come up with a protocol at our hospital.”
Afterward, Dr. Chandrasekhar emphasized how important it is to talk to patients about the options with this disorder. “This is one entity where you need to spend the time to educate the patient,” she said, “because there’s a reasonable chance they’re going to get better if you do nothing. If you do nothing and they don’t get better, there’s a reasonable chance that injecting with steroids at that point, if you don’t wait too long, will work.”
In her experience, she said, patients almost never opt for no treatment, usually because they’ve already had a “no treatment” period while they waited before seeing a physician.