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5 StancIarctizing Procedures A desirable goal is widespread adoption of a standard procedure for measuring and evaluating tinnitus, and it would be particularly nice to be able to put forth that standard procedure here. Unfortunately, such action is premature. Too little is known about crucial aspects of tinnitus behavior to be able to specify the best pro- cedures for assessing it. Instead, we can offer only some suggestions about what a standard procedure of the future might include. MEDICAL EXAMINATION As has been noted several times in this report, tinnitus is itself not a discrete disease entity; rather, it is a symptom that is produced by many known and unknown causes and diseases. For this reason, it is wrong to begin by treating the symptom, whether with drugs, tinnitus maskers/instruments, or whatever. m e first step should always be to try to diagnose and treat the underlying cause. Of course, some causes of tinnitus are themselves not treatable, given current knowledge, and palliatives for the tinnitus are the only recourse. m is fact does not exempt the clinician from the obligation to try to establish the underlying disorder. m is section is intended only to indicate the wide variety of possible causes to be considered by the responsible physician-- and should not be taken as a complete guide to diagnosis or treatment. Ever since the introduction of tinnitus maskers/ instruments as a palliative for problem tinnitus there has been concern in some quarters that eliminating this symptom may be "covering up" an important sign of a seri 117
118 ous medical problem--for example, an eighth-nerve tumor. This concern may be exaggerated, because no present treat- ment of tinnitus eliminates it permanently; the concern also appears to be based on logical considerations, not on widespread experience or even anecdotes about such occurrences (see, for example, Miller, 1981). However, even if documented instances of a serious illness being obscured by effective treatment of tinnitus are rare, the point is well taken. Just as patients complaining of tinnitus deserve complete audiological examinations, they also deserve medical examinations that emphasize those general bodily problems that are known to be associated with tinnitus. Of course, all of the general physiologi- cal abnormalities that may produce tinnitus have yet to be identified, but we are able to indicate certain items that deserve attention. 1. Blood pressure. The commonly observed variations in tinnitus with stress and the blood Pressure changes _ _ known to accompany stress imply that altered m~croc~rcu~a- tion in the cochlea may be the basis for some tinnitus. Treating the tinnitus with a masker/instrument or other agent may be less direct than treating the blood pressure problem itself. 2. Kidney function. It is commonly asserted that the ear is like the kidney in that both structures are con- cerned with maintaining normal electrolyte concentration gradients. This similarity between the two structures causes them to react similarly to certain agents. Thus, verification of normal kidney function seems advisable in sufferers from severe tinnitus. 3. Drugs. The medical examination should establish what drugs--both physician-prescribed and self- prescribed--the patient takes, and on what schedule(s). Aspirin and other salicylate-bearing agents are obvious ones to eliminate if possible, but other drugs, or com- binations of drugs, may be responsible for a particular individual's tinnitus, and attempts to relate the onset of tinnitus episodes to patterns of drug usage may be worthwhile. If there is a suspicion of the tinnitus being drug induced, a further step would be to prescribe substitute drugs for short periods of time and observe any effects on the tinnitus. 4. Diet and allergy. These are probably very infre- quent causes of tinnitus, but verification of a balanced diet, and suggestion to the patient to be alert to pos- sible temporal associations between tinnitus episodes and exposures to common allergy-producing agents, cannot hurt.
119 5. Other conditions. Goodey (1981) and Schleuning (1981) argue that a general medical examination for a tinnitus sufferer should also include tests for infections of the head, neck, and teeth; hypothyroidism; hyperthy- roidism; early diabetes; hypoglycemia; disturbance of serum lipids; high blood viscosity; autoimmune disease; vasospastic disease; meningitis; multiple sclerosis; and migraine. AUDIOLOGICAL EXAMINATION Many hearing specialists believe that a complete audio- logical examination should precede the prescribing of any form of treatment for tinnitus, but this is not universal. Experts also differ in their strength of feeling about the necessity for a complete audiological examination when the primary symptom is tinnitus (Shulman, 1981:205-207). A complete examination would include, but not necessarily be limited to, air- and bone-conducted pure-tone threshold measures, speech threshold and discrimination tests, tym- panometry and reflex testing, and site-of-lesion tests if indicated. Following these standard tests, the tinnitus itself should be documented. The measures made should include, but not necessarily be limited to, pitch and loudness matches, a test of maskability, and a test for residual inhibition. At present there exist numerous procedures for making these various measures, and, unfortunately, they do not always produce the same outcome. It may be that particular methods will eventually prove more reli- able and valid than others for particular forms of tin- nitus, but at the moment it is premature to specify par- ticular psychophysical procedures for the various measures or for different forms of tinnitus. Nevertheless, it is possible to make certain general recommendations about measures and procedures. 1. Some tinnitus is said to be "masked" by sounds from numerous locations across the spectrum and some by both ipsilateral and contralateral waveforms. The use of several tonal or narrowband maskers, both ipsilaterally and contralaterally, would thus seem worthwhile, for it may be that some tinnitus sufferers would be better served by a masker waveform different from that most effective against an external sound of the same frequency and band width.
120 2. Similarly, residual inhibition should probably be studied with several maskers, both ipsilaterally and contralaterally. 3. It follows from the previous two recommendations that testing should not be done using loudspeakers to present the stimuli, but with headphones, and preferably with headphones having a good seal, good high-frequency response, and high intermural attenuation. 4. It is important that pitch matches be verified with tests at octave frequencies above and below the matched frequency, and since pitch matches are so diffi- cult for unpracticed subjects, it would be advisable to have a repeat determination either later in the exami- nation session or at another time. 5. Because tinnitus is notorious for its variability, both within and across days, it is important that the current status of the tinnitus be established at the time of the tinnitus examination. Specifically, the patient should be asked whether the tinnitus being experienced is typical, and, if not, how it differs and how greatly it differs from the typical problem day. If the tinnitus of the current day is judged to be sufficiently atypical, the patient should probably be asked to return during a more typical episode; otherwise, the measurements made could be very misleading to the clinician attempting to prescribe for the problem. In today's busy clinics, such a procedure may be very inconvenient both for the patient and the clinician, but the inconvenience and delay ought to be offset in the long run by better diagnosis and treatment. 6. A procedural suggestion made by the Oregon group appears well advised: measures of tinnitus magnitude should be made using procedures that involve only suc- cessive increases in intensity, for the premature intro- duction of high intensities could produce a residual inhibition that would invalidate later measures. m e suggestion applies, of course, to measures of tinnitus other than magnitude measures; in general, stimuli of long duration and relatively high intensity should be avoided throughout the tinnitus examination. 7. Whenever possible, it would be advisable to report loudness matches in both SL and SPL units. 8. Attempts to determine the monaural or binaural nature of the tinnitus appear worthwhile. As noted in the section n Is the Tinnitus Monaural or Binaural? in Chapter 3, a binaural but asymmetric tinnitus can appear to the patient as having a monaural origin, but such a
121 tinnitus will in many instances be much more resistant to a (monaural) masker/instrument than will a truly monaural tinnitus. One procedure for attempting to determine the monaural/binaural nature of the tinnitus has already been described (see "Is the Tinnitus Monaural or Binaural?" in Chapter 3), and others could surely be developed. The examiner must always remember that a person's tinnitus may be composed of many different spectral components (see "Quality of the Tinnitus" in Chapter 3) and that some of these may be monaural, some binaural and approxi mately equal in magnitude, and some binaural and quite discrepant in magnitude. Ideally, the monaural or bin - aural nature of each of the components would be determined along with their relative annoyances, so that an optimal masker program could be chosen. Additional measures and procedures that would be desir- able will undoubtedly become clear as our knowledge of the origins of tinnitus increases.