Tinnitus Flashcards
Intro
-Tinnitus is an auditory phantom perception of sound that originates in the head (Jastreboff, 1990)
-There is a strong relationship between causes of hearing loss and causes of tinnitus; some common causes of tinnitus include noise exposure, head injury, and medications.
o There is also a strong correlation between tinnitus
and otosclerosis, ear infections, acoustic neuroma,
Meniere disease, and aging (Jastreboff & Jastreboff,
2000)
o However, many people experience idiopathic
tinnitus.
Prominent Theories Intro
” It is thought that the mechanism responsible for coding tinnitus can originate from many different places along the auditory system and brain including the cochlea, the auditory nerve, the brainstem, or the central nervous system.
“ Two prominent theories of tinnitus production and perception are the neurophysiological model and the central gain theory.
neurophysiological model
” The neurophysiological model for tinnitus (Jastreboff, 1990; Jastreboff & Hazell, 1993)
o The process by which tinnitus emerges is divided into four stages:
“ Generation in the peripheral auditory system related to cochlear disorder
“ Detection in the subcortical auditory centers based on pattern recognition
“ Perception and evaluation in the auditory cortex
“ Sustained activation of the limbic and autonomous nervous system (Jastreboff, 1990)
“ This fourth stage only occurs when negative emotions are attached to the perception of tinnitus allowing a feedback loop to develop
Central Gain Theory
” The central gain theory is based on a “homeostatic plasticity mechanism”
o Works to stabilize the average firing rates of central auditory system neuron in response to increased spontaneous activity from sensory deprivation (Chrostowski et al., 2011; Norena, 2011; Schaette & Kempter, 2006).
o With this model, a damaged cochlea would result in reduced output from the auditory nerve, which would, in turn, trigger the amplification of “neural noise,” which would be perceived as tinnitus.
“ This compensatory increase in the central auditory activity in response to the loss of sensory input is referred to as central gain enhancement.
o Other mechanisms that could alter central gain include:
“ Loss of inhibition in central auditory pathways consequent on hearing injury (Eggermont and Roberts, 2004; Richardson et al, 2012)
“ Changes in inhibition associated with aging (Caspary et al., 2005)
What causes some individuals to have tinnitus that is so intrusive it significantly changes their quality of life or even becomes debilitating
” Tinnitus is related to a library of patterns in auditory memory and also, by reference to the limbic system, associated with an emotional state (Jastreboff and Hazell, 1993).
“ If the neuronal networks associated with tinnitus are mapped such that they consider the tinnitus signal to be important, we will continue to be aware of the meaningful signal leading to a tinnitus problem (Hallam, Jakes, & Hinchcliffe, 1988; Hallam, Rachman, & Hinchcliffe, 1984).
“ Unfortunately for those suffering from tinnitus (~25% of people with tinnitus), emotional associations are usually extremely negative; a strong negative connection to tinnitus is more likely to develop when tinnitus emerges during periods of stress (e.g. illness, loss of a job, death in the family).
Tinnitus is considered intrusive and bothersome when it affects …
o Sleep
o Concentration
o Hearing
o Mood.
Factors that make tinnitus worse are
o Stress o Noise exposure o Fatigue o Certain medications o Diet o Biochemical changes o Self-monitoring tinnitus o Internet searching about tinnitus - The process of "negative counseling" as described by Jastreboff and Hazell (1993) is another way that that tinnitus can become highly intrusive to an individual.
Audiologic Eval
” The first component of a tinnitus evaluation in the clinic is a standard audiologic assessment (Henry et al., 2008).
o During pure-tone testing, the observed presence of a slope on the audiogram can aid in localization of the perceived pitch of an individual’s tinnitus; this is based on the hypothesis of discordant damage of IHC and OHC systems and is frequently observed in clinical practice (Hazell, 1987).
o Similarly, otoacoustic emissions can identify areas of limited damage in the cochlea; data from by Jastreboff and Hazell (1993) indicates that tinnitus pitch may well be associated with abnormal OAE distortion products even before any abnormality is noted on audiometry.
Patient Reaction
” Next, the patient’s reaction to the presence of tinnitus should evaluated. The Tinnitus Handicap Inventory (THI) can be used obtain a global index score of the patient’s tinnitus severity, which will serve as a baseline measurement for validation of outcome measures as well as guide audiologic testing and counseling (Henry et al., 2008).
o The THI is an ideal measure of perceived tinnitus severity, given that it is:
“ Widely used
“ Easy to administer
“ Highly reliable
“ Valid measure of tinnitus-related handicap
(Kleinstauber, Frank, & Weise, 2014)
Pyschoacoustic tests - general
” The tinnitus evaluation is conducted to measure tinnitus objectively through psychoacoustic testing.
o The measurements allow clinicians to:
“ Quantify tinnitus
“ Fitting of sound maskers
“ Monitoring changes in tinnitus perception
Loudness Matching
Loudness matching (LM) involves asking the patient to match an external 1000 Hz tone to the loudness of their tinnitus.
When tested repeatedly, the majority of tinnitus patients are very reliable at producing consistent LMs, thought to reflect an “internal standard” available for comparison with the external tone (Vernon, 1996).
Pitch Matching
o During pitch matching, the patient is provided with pure-tone stimuli and is asked to identify the sound that is most like their tinnitus based on its pitch.
“ Pitch matching for tinnitus involves several complicated factors, and there is great variability in the precise location of identified frequencies (Graham & Newby, 1962).
“ However, patients can typically compare the pitch produced by a pure-tone to the most prominent pitch of their tinnitus (Tyler, 2000).
Minimum Masking Levels
o Minimum masking levels (MMLs) are a measure of the amount of noise required to mask the tinnitus.
“ They are typically obtained using a broadband noise stimulus and asking the patient to identify when they can no longer hear their tinnitus.
“ The test-retest reliability of MMLs is good (Meikle et al., 2008).
“ Both LMs and MMLs are significantly reduced following effective tinnitus treatment (Jastreboff, Hazell, & Graham, 1994).
Loudness discomfort levels
o Loudness discomfort levels (LDLs) are another important quantification to make when evaluating tinnitus in the clinic.
“ For some tinnitus therapies, such as tinnitus retraining therapy, the measurement of LDLs is considered crucial for determining the course of treatment and for monitoring treatment outcome (Henry et al., 2002).
Tinnitus Masking
” Tinnitus masking (TM) is a sound-based therapy (Vernon, 1977)
o The main objective of TM is to provide a sense of relief from tension or stress caused by tinnitus using a broadband sound (Vernon & Meikle, 2000).
o Maximizing a sense of relief can be accomplished with complete masking or partial masking (Henry et al., 2008)
o TM patients normally are fitted with ear-level devices that present wide-band noise to the ears
“ Patients are instructed to adjust the noise to the level that provides the greatest sense of relief
o Patients also are advised to use other sound-producing devices to achieve relief, including portable music players, sound machines, sound pillows, etc.
o Counseling is used with TM, but the use of therapeutic sound to induce a sense of relief is the primary mode of intervention (J. A. Henry et al., 2002; Schechter & Henry, 2002).
TRT
” Rooted in the Neurophysiology Model for tinnitus (Jastreboff, 1990), Tinnitus Retraining Therapy (TRT) is another tinnitus management strategy that includes the use of a sound-based intervention.
o Jastreboff & Jastreboff (2000) propose that Tinnitus Retraining Therapy (TRT), when implemented properly
“ Is highly effective
“ Does not have side effects
“ Needs to be implemented over a finite amount of time
“ Can be used on all patients
o The signature features of TRT is include a combination of directive counseling and sound therapy to counteract the pathological positive feedback loop and promote habituation to the tinnitus (Jastreboff, 1993).
“ The directive counseling is aimed to educate patients about the auditory system and explain the mechanisms by which tinnitus is thought to arise.
o In TRT, patients are divided into one of five groups according to the severity of their tinnitus, the presence or absence of significant hearing impairment and the presence or absence of hyperacusis.
o The sound therapy acts by providing the auditory system with constant, low-level, neutral auditory signals to
“ (1) decrease the contrast between tinnitus-related neuronal activity and background neuronal activity
“ (2) interfere with the detection of the tinnitus signal
“ (3) decrease enhanced gain within the auditory pathways.
o With TRT, the patient should hear the tinnitus clearly, but with constant sound in the background (Henry et al., 2008).
“ The background sound reduces the contrast between the tinnitus and the quiet environment, thus making the tinnitus less likely to attract attention (passive attention diversion).
o TRT patients are supposed to use sound in this way every day to eventually achieve habituation (i.e., reduction or elimination of tinnitus reactions and perception).
o The protocol for TRT recommends that patients should receive follow-up sessions at monthly intervals for the first three months and then at six, nine, 12, 18 and 24 months (Jastreboff, 2004).
literature to support the effectiveness of these therapies as evidence you would present to a third-party payer to encourage the incorporation of tinnitus services - TINNITUS MASKING ONLY
” While significant research on TRT has been completed, less empirical investigations have considered the efficacy of TM.
“ Vernon and Meikle (2000) evaluated data obtained from a tinnitus clinic with a sample of 828 patients and concluded that 61% of patients who underwent TM therapy were satisfied with the effectiveness of their treatment.
literature to support the effectiveness of these therapies as evidence you would present to a third-party payer to encourage the incorporation of tinnitus services - TINNITUS MASKING AND TRT
” A quasi-randomized trial by Henry et al. (2006) comparing TM with TRT in a cohort of 123 participants concluded that both tinnitus masking and TRT were effective treatment options; based on effect sizes, both treatments showed considerable improvement overall.
o While TM effects remained fairly constant at subsequent follow-up intervals, TRT effects improved incrementally.
o For patients experiencing significant distress, tinnitus severity as measured using the THI was improved by 29.2 points in the TRT group as compared to 16.7 points in the TM group at 18 months.
o Ultimately TRT had a greater positive outcome for participants than tinnitus masking for long term management (Henry et al., 2006).
literature to support the effectiveness of these therapies as evidence you would present to a third-party payer to encourage the incorporation of tinnitus services - JUST TRT AND CONCLUSIONS
More recently, Bauer et al. (2017) conducted a randomized control trial comparing TRT to standard of care treatment (SC) in a cohort of 38 adults with chronic, bothersome tinnitus.
o This study found a significant improvement in tinnitus impact for both TRT and SC therapies, with a larger treatment effect obtained in the TRT group
o Additionally, lasting therapeutic benefit was evident at 18 months suggesting good evidence of long-term impact of TRT.
“ Ultimately, TM and TRT are useful therapies for patients with bothersome tinnitus and should be considered clinically relevant and significant for the purposes of improved patient quality of life and insurance coverage.
(Jastreboff, 1990)
Tinnitus is an auditory phantom perception of sound that originates in the head
