Tinnitus--Introduction

AUD 733 Week 1

Tinnitus Definition:

From the Latin tinniere (to ring) Refers to an auditory perception not produced

by an external stimulus Commonly described as a ringing, roaring,

hissing, or whooshing Ranging from high pitch to low pitch or even

a noise-like sound (with no tonal quality)

Pronunciation Controversy Tin’-i-tis (stress on the first syllable and

the middle “i” uses the short pronunciation)

Tin-i’-tis (the middle “i” is long and the usual pronunciation of the suffix “itis” is used

The controversy goes on

The Arguments The researchers and some individuals from the

American Tinnitus Association (ATA) argue that “itis” should be pronounced with a long “i” , as described in numerous dictionaries

The majority of other individuals use the short vowel sound for the middle “i” and may argue that “itis” with a long “i” suggest some sort of inflammation which is not accurate when referring to tinnitus

Suggestion Use whichever pronunciation you are

comfortable with Explain briefly to your patients that they

may here either pronunciation used and both are acceptable

What Tinnitus IS NOT Auditory hallucinations are not the same as

tinnitus Auditory hallucinations may be

psychological or may have a true neurologic foundation

More on What Tinnitus Is The exact pathophysiology of tinnitus is

unknown Many Mechanisms have been sited as

possibly producing tinnitus Outer hair cell decoupling from the tectorial

membrane Hyperactivity of neural firing Hypoactivity of neural firing

Cont… Improper functioning of the olivocochlear

bundle (efferent auditory pathways) resulting in a lack of normal inhibition

Basic Concepts on the Origin of Tinnitus It is the chronic perception of a sound that

has no external source. The auditory sensation is continually generated by aberrant neuronal discharges in the auditory nervous system

The brain erroneously interprets the signal as sound/s

Site of Origin The cochlea seems like a likely site because we

know that damage to the cochlea from salicylates (aspirin), noise exposure, and other factors produce tinnitus

But surgical severing of cranial nerve VIII with tinnitus remaining present points toward a central rather than peripheral origin

Postulated course of tinnitus(by Sweetow in Hearing Disorders, Ed. By Jerry Northern (1996))

“An acute insult (or offending agent) leads to a chronic signal, which leads to a central modification, which leads to psychological enhancement, which leads to intractable tinnitus.”

Characterizations of Tinnitus As mentioned earlier, tinnitus can vary in

pitch, loudness and tonal quality It may be constant, pulsed or intermittent It can arise suddenly or slowly It may be heard in the ear/s (tinnitus

aurium) or in the head (tinnitus cranii)

Classifications Literature describes objective and

subjective tinnitus Objective-is audible to an observer (using a

stethoscope or by listening near the ear) Present in less than 5% of overall tinnitus

cases Usually a cause can be determined and

treated medically

Cont.. Objective Tinnitus

Usually associated with vascular or muscular disorders Arteriovenous aneurysms, abnormally patent

Eustachian tube/s, glomus jugulare tumors, palatal myoclonus, spasms or tics of the stapedius or tensor tympani muscle/s

Often pulsatile and synchronous with the patient’s heartbeat

Subjective Tinnitus Audible only to the patient The most common, occurring in over 95% of

tinnitus patients ( we will focus on subjective tinnitus for the rest of this course)

Associated with practically every known otologic disorder

Also related to a host of nonauditory pathologies See separate chart/page in course content for

pathologies associated with subjective tinnitus CLICK HERE to view page now

Epidemiology View information from the Tinnitus Data

Registry developed by the Oregon Health Sciences University (OHSU). It has been in existence since 1975 and has some data published at http://www.ohsu.edu/ohrc-otda/otda.html

Prevalence in the U.S. 40-50 million Americans experience

chronic tinnitus Approx. 2.5 million are debilitated by the

tinnitus

Other Facts About Tinnitus Approx 60% bilateral 30 %, unilateral 10% perceived in the head About three times more men than women

seek treatment for tinnitus Why?

If a person has transient episodes of a tinnitus-like sound, it would not be considered chronic. If tinnitus occurs occasionally and only lasts a few minutes per episode, it would not be considered pathological.

What Makes Tinnitus a Problem? It is not known why tinnitus becomes or is

a problem for some individuals and not for all who experience it. It is suggested, however, that individuals already predisposed to psychological disturbances are more likely to be negatively impacted by the existence of tinnitus.

Correlates No absolute correlation between the quality of the

tinnitus and the etiology For example, low-frequency roaring tinnitus is often

reported with Meniere’s disease but NOT always, and roaring tinnitus can occur with other conditions

It is unknown if acoustical qualities correlate with the perceived severity of the problem For those who seek treatment, the loudness and pitch of

the tones “matched” to the tinnitus do not predict the severity of the problem. We do not have data on those who are not bothered by their tinnitus and do not seek intervention.

Subjective Rating of Tinnitus Loudness

On a scale of 1 to 10, 1 being the “softest sound imaginable” and 10 being the “loudest sound imaginable”, most of the subjects (70%) rate their tinnitus loudness between 4 and 8. About 20% rate it between 8 and 10, and 10% rate it below 4.

Information From the Tinnitus Data Registry