Few Tests, 1 Treatment
As do rheumatologists, otolaryngologists commonly treat sudden SNHL with corticosteroids. The big difference, Dr. Rubinstein says, is that these patients typically receive a one-week course followed by tapering over the second week.
“To treat autoimmune inner ear disease, you need significantly longer courses of high-dose steroids,” he says—typically for at least a month to start. “Before I subject somebody to that experience, which is incredibly unpleasant, I’ve got to be pretty confident that that’s what we’re dealing with. So I want to see evidence that the hearing loss is progressing.”
Is there a role for Hsp70 antibodies to help distinguish sudden SNHL from autoimmune SNHL? Dr. Rubinstein says unfortunately no. Although testing for the presence of Hsp70 antibodies cannot distinguish sudden from autoimmune SNHL, the test can help predict responsiveness of rapidly progressing SNHL to glucocorticoids, he notes. Periodic audiograms can help confirm that the hearing loss is indeed rapidly progressing, he adds, while magnetic resonance imaging is also routine because the loss is often asymmetric.
“When someone has asymmetric hearing loss, we always image them to look for acoustic tumors,” he says. Meningeal carcinomatosis can also cause bilateral, rapidly progressive hearing loss. “The purpose of the MRI scan is to rule out other conditions, not to rule in autoimmune inner ear disease. There’s no imaging correlate of the condition, so it’s really just based on hearing tests,” he says.
If a differential diagnosis points to autoimmune SNHL, doctors have traditionally treated patients with three months of high-dose glucocorticoids and then tapered the dose while conducting hearing tests to find the lowest possible dose that allows hearing to be maintained. Some patients can be successfully weaned from the steroids; for others, the tapering has led to flares that require ramping up the dose again.
Clinicians have periodically assessed alternatives to high-dose glucocorticoids, such as methotrexate, which has lower toxicity and fewer side effects. A few small studies have suggested methotrexate may help treat patients with refractory SNHL, although larger placebo-controlled trials haven’t found a significant benefit. One multi-center clinical trial, for example, enrolled patients who had bilateral, rapidly progressive hearing loss and had at least partially responded to a month-long dose of prednisone.5 The trial then randomized one arm of patients to methotrexate and the other to continued prednisone.
The methotrexate arm “failed miserably,” Dr. Rubinstein says. “By that point, methotrexate had become pretty popular for treating it, but the evidence was pretty clear in the trial that methotrexate didn’t help.”
