For inner ear treatments, intratympanic gentamicin has been shown to be effective, but there is no strong agreement on appropriate dosing, timing, and delivery method, said Soha Ghossaini, MD, an otologist-neurotologist at Ear, Nose, and Throat Associates of New York. “We have to remember that intratympanic gentamicin can potentially cause hearing loss in a good percentage of the patients, depending on the dose,” she said.
Explore This IssueMarch 2019
A key question is when to use the drug in patients who have good hearing. “The consensus is to use them in patients with impaired hearing function and patients with good contralateral vestibular function,” she said.
Some researchers have advocated for a “titration” protocol and not systematic weekly or monthly injections, with end points of symptom resolutions and signs of hearing loss, realizing that these signs will be delayed by two or three days after treatment (Clin Otolaryngol. 2015;40:682-690). Tests such as ENG, VEMPs, and head-impulse test (HIT) were not found to establish end points for treatment with gentamicin, Dr. Ghossaini noted.
Intratympanic steroid therapy, particularly dexamethasone, is becoming more popular for vertigo control. Even though some studies have found that gentamicin controls vertigo better, steroids come with fewer risks, she said. She added that patients might need repeated treatments and that adding oral betahistine to steroid treatment has been shown in one study to produce better vertigo control. She added that no improvement in hearing has been found after long-term follow up.
Surgical procedures for Ménière’s have been found to have a range in efficacy, Dr. Miller said.
Researchers have found that overpressure devices reduce vertigo frequency, but the results on hearing loss have been mixed (Clin Otolaryngol. 2015;40:682–690; Clin Otolaryngol. 2015;40:197–207; Cochrane Database Syst Rev. 2015;CD008419). The official American Academy of Otolaryngology-Head and Neck Surgery position is that there is “some medical evidence” to support their use as a second-level therapy after medical treatment has failed.
Endolymphatic sac surgery isn’t supported by histopathologic studies for shunt placement, but has been found to bring vertigo relief for some patients. “Although we don’t necessarily understand the basis behind it, it can be effective,” Dr. Miller said.
Vestibular nerve section has been found to lead to complete vertigo resolution in 85% of patients, based on two approaches that were studied, Dr. Miller said. The number isn’t 100%, she said, likely because the literature mostly reports on cases of transection of the nerve and not on cases that also involve destruction of Scarpa’s ganglion, which would bring about a more complete effect.
Cochleosacculotomy can be 60% to 80% effective in eliminating vertigo, she said.
Transcanal labyrinthectomy is a shorter procedure than transmastoid labyrinthectomy and has lower morbidity, but also has a lower success rate. It involves a transcanal approach, so it can be more difficult to remove all of the vestibular end organs, Dr. Miller said. This, she said, might be a better approach for older or frail patients.