In the past year, about 10 percent of adults in the United States have experienced tinnitus lasting at least five minutes. In severe cases, tinnitus can interfere with work and sleep, and some patients experience anxiety, depression, and extreme life changes.
Even though tinnitus is relatively common and affects quality of life, historically some clinicians have thrown up their hands when confronted with the challenges of treating it. After all, tinnitus is not a disease, but rather a symptom that can result from multiple conditions affecting the auditory system, which includes the ear, the auditory nerve that connects the inner ear to the brain, and the parts of the brain that process sound.
To help clinicians determine the most appropriate interventions to improve symptoms and quality of life for people with tinnitus, the American Academy of Otolaryngology–Head and Neck Surgery Foundation (AAO-HNSF) published the first evidence-based clinical practice guideline for the evaluation and treatment of chronic tinnitus. The guideline, which was included as a supplement to the October issue of Otolaryngology–Head and Neck Surgery, emphasizes interventions and therapies that are deemed beneficial and discourages those that are time-consuming, costly, and ineffective (2014;151[suppl 2]:S1-S40 http://oto.sagepub.com/content/151/2_suppl/S1.full).
“Overall, I am impressed with the guideline,” said James W. Hall III, PhD, a member of The Hearing Journal’s Editorial Advisory Board and an adjunct professor of audiology at Salus University, who was not an author of the clinical practice guideline.
“Evidence-based guidelines for tinnitus assessment and management are definitely needed. The authors preparing the guideline included in the document all major topics relevant to tinnitus assessment and management.”
A multidisciplinary team of otolaryngologists, audiologists, and other healthcare professionals, as well as consumer advocates, developed the guideline's 13 recommendations for the evaluation of adult patients with persistent, bothersome primary tinnitus in which the underlying cause is not clear.
The guideline excludes patients with secondary tinnitus, which is associated with a specific underlying cause other than sensorineural hearing loss, because these patients are often excluded from randomized, controlled trials of tinnitus management. The guideline also excludes patients with tinnitus related to complex auditory hallucinations or to hallucinations associated with psychosis or epilepsy, and patients with pulsatile tinnitus.
The guideline begins with recommendations about patient examinations. First, clinicians should perform a targeted history and physical examination at the initial evaluation of a patient with presumed primary tinnitus to identify conditions that, if quickly identified and managed, might relieve tinnitus.
Second, clinicians should obtain a prompt, comprehensive audiologic examination in patients with tinnitus that is unilateral, persistent (present for at least six months), or associated with hearing difficulties. For patients who present with tinnitus that does not meet any of these conditions, an initial comprehensive audiologic examination was listed as an option.
“There are two action statements that support audiologic assessment for these patients,” said David E. Tunkel, MD, lead author of the tinnitus clinical practice guideline and chief of pediatric otolaryngology at Johns Hopkins School of Medicine.
“The first just identifies who should have prompt audiologic assessment, and the second notes that audiologic assessment can be performed for any patient with persistent, bothersome tinnitus.”
Robert Sweetow, PhD, clinical professor of otolaryngology–head and neck surgery at the University of California, San Francisco, who was not involved in developing the guideline, was disappointed by the lack of a recommendation for routine audiologic care.
“Without audiologic measures, I don't think the full range of opportunities for help can be given,” he said.
The most important recommendations in the clinical practice guideline focus on identifying patients in need of clinical management, thereby limiting unnecessary testing and treatment, said Pawel J. Jastreboff, PhD, ScD, MBA, professor of otolaryngology at Emory University School of Medicine, who was not a member of the guideline development group.
For example, clinicians are encouraged to distinguish patients with bothersome tinnitus from patients with non-bothersome tinnitus, and further distinguish patients with bothersome tinnitus of recent onset from those with symptoms lasting at least six months.
The guideline also recommends that clinicians avoid imaging studies of the head and neck unless the tinnitus is localized to one ear, pulsatile, or associated with focal neurological abnormalities or asymmetric hearing loss.
Moreover, clinicians should not routinely recommend transcranial magnetic stimulation or medications like antidepressants or anticonvulsants because these interventions may not effectively treat tinnitus and could cause side effects, including worse tinnitus.
Similarly, dietary supplements such as ginkgo biloba, melatonin, and zinc are not recommended because they have no proven efficacy and pose potential harm to patients.
Dr. Jastreboff also agreed with the recommendation that clinicians educate and counsel patients about management strategies.
On the other hand, he found controversial the statements identifying cognitive–behavioral therapy as a recommendation—a treatment that clinicians should recommend—and sound therapy as an option—a therapy that clinicians may recommend.
“Sound therapies are unjustly underappreciated, while the usefulness of cognitive–behavioral therapy in practice is very limited,” he said. “There are very few therapists who can do it properly for tinnitus, and it is not addressing hyperacusis and hearing loss, which sound therapies are doing and which very frequently accompany tinnitus.
“In my opinion, it is crucial to treat decreased sound tolerance—both hyperacusis and misophonia—and hearing loss together with tinnitus to achieve a high level of success.”
Dr. Tunkel, on the other hand, said that cognitive–behavioral therapy is one of the best-supported treatment strategies for tinnitus management, with a number of reviews and trials behind it.
“While the availability and use of cognitive–behavioral therapy may be limited, the usefulness may not be,” he said.
Dr. Sweetow also is a proponent of cognitive–behavioral therapy.
“More and more audiologists, in addition to psychologists, are being trained to provide this assistance,” he said, adding that he strongly believes in relaxation training as well.
In addition, he was pleased with the recommendation of a hearing aid evaluation for patients with hearing loss, which is frequently associated with tinnitus.
“I believe that the most important message conveyed in the guideline is that otolaryngologists should not tell patients that there is nothing that can be done to help them.”
EVALUATING THE EVIDENCE
Dr. Tunkel noted the high-quality evidence base for the clinical practice guideline.
“We looked at randomized, controlled trials and systematic reviews, and also looked at potential sources of bias in the evidence,” he said.
“A major issue was that some studies of interventions for tinnitus had methodological flaws that limited our ability to recommend treatment strategies. These flaws included problems with randomization, inadequate placebo conditions, and variation in entry criteria and outcomes measures.”
Dr. Hall agreed that the quality of the evidence base for the clinical practice guideline generally was good.
“Best practice is, in effect, evidence-based practice,” he said. “That is, decisions regarding how to evaluate, diagnose, and manage patients with tinnitus and other problems must be guided by research findings.
“The guidelines appropriately cite not only the research evidence in support of the recommendations, but also the strength or quality of the evidence behind each recommendation.”
The guideline is a step in the right direction, Dr. Jastreboff noted.
“I believe that these guidelines should be helpful, provided that people take them as suggestions and not strict rules,” he said. “They should help in avoiding some errors in treatment, but they are not sufficient for people who are not familiar with treating tinnitus patients.”
Tinnitus experts had additional suggestions beyond the guideline recommendations. For example, Dr. Sweetow advised that patients first see an otolaryngologist for proper diagnosis, and then see an audiologist trained in tinnitus management.
“For nonmedical treatment, trained audiologists are the best professionals for helping patients find relief,” he said. “Physicians simply don't have the necessary time to spend with the patients.”
A challenge moving forward is convincing otolaryngologists that audiologists can greatly benefit tinnitus patients, he added.
Dr. Jastreboff sees value in tinnitus retraining therapy (TRT), which uses a combination of low-level broadband noise and counseling to achieve the habituation of tinnitus, such that patients are no longer aware of their tinnitus, except when they focus their attention on it.
“TRT is effective for all types of tinnitus, and its effectiveness does not depend on tinnitus etiology,” said Dr. Jastreboff, who pioneered the approach. “I believe it is most effective and addresses tinnitus, hyperacusis, misophonia, and hearing loss.”
Cochlear implants are sometimes used in people who have tinnitus along with severe hearing loss. The device brings in outside sounds that help mask tinnitus and stimulate change in neural circuits.
Meanwhile, some patients have turned to acupuncture, but the poor quality of the data and the limited potential for harm kept the clinical guideline development group from making a recommendation about this therapy.
No matter which treatment is used, the evaluation of its effectiveness should involve the assessment of tinnitus severity and changes in the impact of tinnitus on a patient's life, Dr. Jastreboff said.
To a large extent, success in tinnitus management depends on aligning the treatment approach with the disorder and related underlying problems for a specific patient, according to Dr. Hall.
“One management approach doesn't work for all patients because tinnitus is not a unitary disorder, but rather a symptom of many potential disorders,” he said.
Various companies are now investigating drugs for the future treatment of tinnitus. For example, Autifony Therapeutics announced in June that the United Kingdom's innovation agency—the Technology Strategy Board, which is now called Innovate UK—had awarded the company £2.2 million for a Phase 2a clinical trial in tinnitus patients with its lead compound, AUT00063. (To find out more about investigational treatments targeting audiological conditions, read the article on page 14 of the September issue of The Hearing Journal, available at bit.ly/HJ-Investigational http://journals.lww.com/thehearingjournal/Fulltext/2014/09000/Funding_Pours_in_for_Investigational_Hearing.1.aspx.)
AUT00063 is a first-in-class Kv3 potassium channel modulator targeting the brain regions that process sound.
Meanwhile, Otologic Pharmaceuticals is investigating whether its antioxidant-based product, NHPN-1010, will reduce the onset of noise-induced tinnitus.
In addition, Auris Medical is developing AM-101 for the treatment of acute inner ear tinnitus following traumatic cochlear injury or middle ear infection. This gel contains an N-methyl-D-aspartate (NMDA) receptor antagonist called esketamine hydrochloride.
Similarly, Otonomy is developing a tinnitus treatment called OTO-311—a sustained-exposure formulation of the NMDA receptor antagonist gacyclidine.
“Medication continues to be explored, but there is no magic bullet yet,” Dr. Sweetow said.
Dr. Jastreboff also expressed skepticism.
“I have seen many claims of ‘highly effective treatment’ over the last 30 years, which turned out to be not true when investigated by independent investigators,” he said.
“I do not believe the cure for tinnitus is possible in any reasonable time, if at all. Our current knowledge of the function of the auditory system and the brain makes a cure extremely unlikely.”
Moving forward, it will be important to better understand the mechanisms responsible for tinnitus being bothersome and to investigate the mechanisms involved in brain plasticity, Dr. Jastreboff said. The American Tinnitus Association is funding research to explore the relationship between tinnitus and tonotopic remapping in auditory regions of the brain.
In the meantime, obstacles remain in the treatment of tinnitus. One of the biggest challenges is “the attitude that nothing can be done for primary tinnitus, so clinicians are not engaged in finding appropriate management strategies,” Dr. Tunkel said.
On a related note, Dr. Jastreboff noted the lack of financial incentives to work with tinnitus patients.
“It takes time and knowledge, and it is not covered by insurance plans,” he said. “One needs to be very passionate to keep working with these patients, or to have other sources of support of the work than patients’ payments.”
Despite these challenges, Dr. Hall remains optimistic.
“Clinicians managing tinnitus now can turn to rather substantial peer-reviewed published research for guidance in how to evaluate and manage their patients,” he said. “There is ample evidence that tinnitus can be accurately diagnosed and, in most cases, effectively managed.
“All patients with tinnitus can be helped, and, with appropriate management, the vast majority of patients with bothersome tinnitus can regain their former quality of life.”