The majority of patients with subjective tinnitus have a significant hearing loss. Use of a well-fitted hearing aid can improve subjective tinnitus in 50% of patients with hearing loss and tinnitus. Hearing aids increase the ambient noise perceived by the patient, thus masking the tinnitus (26). Additionally, restoration of auditory input within the lost frequencies, particularly those matching the frequency spectrum of the tinnitus, lead to central auditory plasticity, which can decrease tinnitus. Ideally, patients with bilateral subjective tinnitus should be fitted with bilateral hearing aids that include a wide, high-frequency amplification band and open ear mold. The open mold will decrease the occlusion effect, and extend amplification at higher frequencies. Ideal hearing aid settings for a patient with hearing loss and tinnitus would include an omnidirectional microphone, a lower compression point, disabled digital noise reduction, and active digital feedback cancellation (26).

Nonpulsatile and pulsatile tinnitus sounds can sometimes be covered (or masked) by external sounds, thus blocking the tinnitus percept and the unpleasant sensations associated with these sounds. To use this therapy effectively, the physician or therapist needs to exclude patients for whom the tinnitus cannot be masked, the masking sound is perceived as worse than the tinnitus sound, or the tinnitus sound is tolerable as it is (27,28). For many patients, use of environmental sounds such as a noise generator or radio can effectively and inexpensively mask their tinnitus. However, in certain situations, use of such environmental sounds may not be appropriate. Use of an ear-level tinnitus masker, a small device that makes a sound matched to the tinnitus sound the patient perceives, yields total relief for 6% of patients and partial relief for 23% to 64% of patients (27,29). The addition of masking tones to amplifications from a hearing aid can mask tinnitus sounds more effectively than a hearing aid alone (30).

For most patients, masking sounds include many of the frequencies of their hearing loss (29). Occasionally, use of masking sounds can lead to residual inhibition, or cessation of the tinnitus sound, for a period of seconds to hours (29). Residual inhibition is hypothesized to result from inhibition of synchronous activity within the auditory pathway from masking sounds that lie within the frequencies affected by hearing loss being presented above the minimal masking threshold (29). Some proponents of other therapies for tinnitus, particularly TRT, feel that tinnitus maskers may prevent habituation to the tinnitus perception and can therefore impede these patients’ ultimate recovery (31). Certainly, those who benefit from tinnitus maskers require ongoing use of the masker to manage their tinnitus, especially if this is their sole treatment strategy (27,29).

TRT is an effective management strategy for both subjective tinnitus and hyperacusis. TRT is based on the concept that habituation to the unpleasant stimulus can minimize the reactions that these patients experience (Fig. 161.4). Up to 80% of patients experience tinnitus without a significant unpleasant association; and tinnitus severity is not equal to the intensity of the perceived stimulus. For patients with complaints of significant tinnitus, Jastreboff hypothesized that an initial link is made between the tinnitus percept and unpleasant limbic and autonomic reactions that lead to an unconscious linkage between the tinnitus sound and the reaction (31). Since habituation to unpleasant stimuli
occurs all the time, Jastreboff surmised that habituation to tinnitus perceptions can occur as well (Fig. 161.4). Unlike other therapies for tinnitus, TRT does not seek to reduce production of the tinnitus sound but instead attempts to change the linkage between the tinnitus perception and autonomic and limbic systems using extensive counseling and sound therapy. Counseling attempts to reclassify tinnitus as a neutral stimulus and is felt to be necessary to allow habituation. Sound therapy decreases abnormal neural activity causing tinnitus and can also be an effective means to decrease hyperacusis via exposure and habituation. Studies have shown that completion of a 12-month course of TRT can decrease scores on the Tinnitus Handicap Index, a validated scale of tinnitus severity, by up to 80% (reviewed in [31]).

Based on success with tinnitus maskers and counseling, investigators sought to incorporate both phenomena into treatment for tinnitus. The Neuromonics device uses sound therapy, extensive tinnitus education, and cognitive therapy to treat patients with tinnitus. Patients begin their therapy by listening to preprocessed mixed “calming music” (a combination of baroque and new age) combined with noise mixed by proprietary algorithm for 2 to 4 hours daily. The sound spectrum of this noise is shaped according to patient’s audiogram to compensate for hearing loss. Over 6 to 24 months, the noise sounds are gradually decreased. The underlying rationale is that initial wide frequency stimulation will counter the auditory deprivation resulting from preexisting hearing loss, pleasant and calming sounds counter negative feedback from the limbic system, and matched tinnitus tones also incorporated into the program will lead to gradual desensitization (32). Following completion of therapy, up to 77% of patients report improvement of their tinnitus (33).

Up to 80% of cochlear implant recipients have moderate to severe tinnitus. All studies examining tinnitus in cochlear implant recipients show an improvement following unilateral multichannel implantation in most implantees (60% to 90%), with some recipients exhibiting improvement of contralateral tinnitus through residual inhibition (34,35,36,37,38). Some patients, however, experience new onset or increased severity of their tinnitus following cochlear implantation (34,35,39). Worsening of preexisting tinnitus and development of new-onset tinnitus is more common in the setting of bilateral cochlear implantation (40).

A wide variety of standard medications and herbal supplements have been used by patients to reduce or alleviate their tinnitus, including anesthetic agents (IV lidocaine), anticonvulsants, antidepressants, antihistamines, benzodiazepines, diuretic, GABA agonists (Baclofen), Ginko biloba extracts, histamine, steroids, and vitamins. Of these, only a few agents have been shown to be effective agents at consistently improving patients’ perceptions of their tinnitus: IV lidocaine, antidepressants, and steroids.

Lidocaine, an amine-type local anesthetic and class 1B antiarrthymic drug, blocks voltage gated sodium channels and has effects on the firing of a number of other neuronal channels. Lidocaine suppresses tinnitus in 40% to 80% of patients. Sites of action are located in both the cochlea and CNS. Intravenous lidocaine may be effective up to 4 weeks following injection, despite an elimination half-time of 90 to 120 minutes in most patients (41). Intratympanic injection of lidocaine is also effective for treatment of tinnitus, but the high incidence of vestibular side effects limit its use (42).

Antidepressants have been tested in a number of trials for the treatment of nonpulsatile tinnitus, including at least five double-blind placebo controlled studies (42,43). These studies are characterized by varying entry criteria, including the duration and severity of tinnitus, drug used, duration of its use, assessment of efficacy, and presence or absence of depression in trial participants. Often these trials were not assessed on an intention to treat basis. Drugs studied include nortriptyline, paroxetine, sertraline, and trimipramine. Overall, however, patients with anxiety, depression, and more severe tinnitus are more likely to benefit from use of these medications (42,44).

Steroids, either intratympanic or orally administered, have been described as an effective method of control of tinnitus for patients with Meniere’s disease (42). However, the majority of trials of steroid therapy for Meniere’s disease utilized control of vertigo as their primary outcome measure. In these trials, control of tinnitus was a secondary or tertiary outcome measure. Intratympanic steroids were shown to be ineffective for treatment of subjective tinnitus in a randomized control trial of 70 patients (45).

A number of dietary supplements and vitamins have been used to treat tinnitus, including multivitamins (A, B1, B3, B6, B9, C, E, magnesium, manganese, selenium, and zinc), antioxidants (flavonoids, Coenzyme Q, carotenoids) and herbal remedies (ginko biloba, cimicifuga racemosa, cornus officinalis, verbascum desiflorum, yoku-kan-san). Although typically considered harmless, these supplements may have significant side effects and may interact with prescription medications. Typically, there is little evidence of efficacy, and often they can be costly (42).

Vascular compression of the vestibulocochlear nerve (CN VIII) as a cause of nonpulsatile or pulsatile tinnitus is highly controversial. In 1975, Jannetta proposed that tinnitus, vertigo, and SNHL could be attributed to vascular compression of CN VIII from redundant loops of the anterior inferior cerebellar artery in the cerebellopontine angle (46). Recent MRI studies documenting frequent, asymptomatic contact between a vascular loop and
CN VIII dispute the existence of this syndrome and caution against microvascular decompression surgery (47). Nevertheless, reports of efficacious microvascular decompression of the vestibulocochlear nerve suggest surgical treatment of vascular loop syndrome may be useful for some patients (48,49

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