RINGING IN THE EAR – TINNITUS
Ringing in the ears will affect everyone. Fortunately for the overwhelming majority of individuals the condition appears fleeting and not sufficiently bothersome to warrant medical attention. However for about 10-20% or more than 50 million Americans the situation causes mild annoyance or distress. In slightly less than 1% of the population tinnitus significantly and negatively impacts on an person’s capacity to enjoy life and for some may be so devastating that it leads to consideration of suicide.
Tinnitus refers to noise a person perceives that does not originate from any external source. No one, not even the most highly trained specialist, possesses any tools capable of confirming the very existence of the complaint. Symptoms are described as ringing, buzzing, hissing, roaring, clicking, sizzling or whistling. Less frequently they mimic cricket-like sounds and at times appear rhythmical.
These sounds may occur continuously or intermittently and with varying intensity. Tinnitus tends to peak between ages 40-70 often becoming less bothersome in the elderly. The incidence in children may rival that in adults, although younger individuals seem more tolerant and less concerned with the ringing.
Traditional concepts suggest tinnitus strikes more men than women. Recent changes in our society now expose an expanding population of women to excessive workplace, military and recreational noise. These factors threaten the stability of the hearing apparatus and predispose to this condition. Actually tinnitus remains one of the more frequent causes of work and military related disability.
Interestingly although environmental exposure to noise shares an indelible link to tinnitus, the incidence appears similar in developed countries and in less advanced and presumably quieter nations in Africa, Asia and parts of South America.
While onset may occur abruptly after head injury or exposure to high level noise, in most cases it develops insidiously. Some individuals localize the ringing to one ear or the other with predominance on the left side. In more than 50% the sounds affect both ears equally or simply seem to be present centrally within the head.
Once present tinnitus may persist, wax and wane or continue unabated for years to decades. Psychological issues significantly impact on both the intensity and degree of perceived nuisance. Tinnitus may be tortuous for those prone to anxiety, depression, irritability or insomnia. Situational stress further enhances an individual’s dismay. Contrariwise ringing may exacerbate any underlying personality flaw.
Tinnitus remains a scientific mystery. Genetic susceptibility probably greatly impacts on the tendency to develop tinnitus but its precise role remains undefined. Until recently most authorities believed the ear itself, specifically damage to the microscopic hair cells or cilia in the cochlea of the inner ear, played a critical role. More recently available functional imaging studies clearly place the auditory cortex in the brain as the principal sound generator. In fact tinnitus may develop or continue after severing the auditory nerve and completely isolating the ear from the central nervous system.
Perhaps damage to structures within the ear may initiate the chain of events leading to the onset of tinnitus but after a short period that original insult no longer seems necessary for ongoing symptoms. An analogous situation occurs in football where the quarterback becomes largely irrelevant once the ball is passed to the receiver.
Complicated neural pathways involving neurotransmitters, neuromodulators and altered sodium, potassium, calcium and chloride ion channels in the central auditory system perpetuate the condition. This new appreciation hopefully will translate into tailored therapy within the foreseeable future.
In any event, a wide assortment of triggers exists for subjective tinnitus, the type only appreciated by the affected individual. It may develop with interruption in the conduction of sound waves to the inner ear. Common causes include the presence of fluid in the middle ear or an obstruction of the external ear canal, perhaps impaction of cerumen commonly referred to as wax. Perforation of the eardrum or tympanic membrane and damage to the bones just beyond it also regularly create problems.
More often damage to the hair cells or cilia of the cochlea in the inner ear initiate the series of events leading to tinnitus. Just as the hair on our head become less dense and fades to gray as we grow older, a parallel situation disturbs the microscopic cilia or hairs necessary for hearing. This age related problem, presbycusis, cannot be avoided. Repetitive exposure to loud noise or even a solitary concert or burst of gunfire irreparably damages these fine cilia and accelerates the process.
Certain medicines may pose a similar toxic threat to the cilia. Aspirin and the related non-steroidal anti-inflammatory drugs (NSAIDs) including Aleve, Advil, Motrin and their generic equivalents naproxen and ibuprofen predispose to tinnitus. Antibiotics such as erythromycin and vancomycin as well as the tetracyclines – Minocin and Doxycycline – may damage the ear. The same holds for the widely prescribed water pills or diuretics, Lasix or furosemide, as well as a long list of cancer therapies.
Other associations include whiplash, head injury, concussion, multiple sclerosis, diabetes and rheumatoid arthritis. Hyper- and hypothyroidism as well as anemia along with an enormous list of miscellaneous conditions bear some undefined relationship to tinnitus.
Meniere’s Disease represents a unique form of tinnitus associated with vertigo or dizziness, hearing loss and a peculiar feeling of heaviness or fullness within the ear. Episodes occur spontaneously and unpredictably over time. Unlike other forms of tinnitus, the hearing loss tends to be in the lower rather than higher frequencies and specifically associated with complaints of roaring and buzzing. Acoustic neuromas and glomus or vascular tumors are other rare but important causes of tinnitus.
A much less frequent type of tinnitus can be appreciated by someone examining the individual. Noise caused by the turbulence of blood rushing past an obstruction in the carotid artery or jugular vein creates a sound capable of detection with a stethoscope placed over the offending vessel. Referred to as objective tinnitus, this pulsatile form requires more thorough investigation. In the same category are spontaneous contractions or spasms of muscles of the soft palate or middle ear.
Central to all of these situations
seems to be apparent or not so apparent hearing loss. Supposedly an audiogram, the commonly utilized hearing test, measures an individual’s hearing range. But this test only has the ability to monitor specific frequencies between 250 – 8,000 Hz. The test lacks the capacity to detect high frequency hearing deficits between 8,000 – 20,000 Hz. Since ever expanding loss typically begins in these higher frequencies it requires time to migrate into the clinically detectable range. The correctness of the old aphorism that tinnitus begets hearing loss should not be surprising.
Additionally audiograms only monitor discrete frequencies. Loss either above or below the specifically tested bands also fails detection. One common denominator that heralds the onset of tinnitus may be subclinical and undetected hearing loss; another relates to a sensitive auditory cortex within the brain.
Routine evaluation may be performed by a general practitioner, an internist, a neurologist or an otolaryngologist – an ENT specialist. Potentially complicating emotional issues may warrant attention. Simple laboratory examination including a blood count, some chemistry tests and monitoring of thyroid function generally suffices. In the absence of specific abnormalities, a plan of treatment may be discussed.
As with any medical condition, advice begins with education regarding the benign nature of the condition and its lack of association with anything more sinister.
Counseling suggests avoiding cigarettes and excessive amounts of both alcohol and caffeine. Illegal stimulants including cocaine and methamphetamine further exacerbate symptoms by creating a hyperdynamic circulation and obviously should be avoided. Nasal allergies must also be addressed.
Beyond these simple nostrums, relatively little scientific support exists for the many treatments championed by the profession. Wide variations among preferred therapies appear between practitioners within a specialty, a country and internationally. Were any specific intervention successful, widespread adoption would occur. Currently no medicine for tinnitus carries the seal of the FDA or its equivalent on the continent – the European Medicines Agency.
The goal of therapy remains improving the quality of life rather than eradicating symptoms. While some individuals respond to one therapy or another, studies point to a lack of uniform benefit compared to a placebo. This being the case, costly interventions and those associated with an increased likelihood of adverse reactions should be avoided. Since symptoms tend to be magnified during the quiet of the night, the white noise made by a radio not tuned to a specific station may provide some relief.
Popular therapies include the older tricyclic antidepressants. Included in this widely prescribed group are Elavil / amitriptyline and Pamelor / nortriptyline. Originally thought to benefit all patients with tinnitus, these tend to aide only those with pre-existing depression. A similar situation exists with the SSRI family: Prozac, Zoloft and Paxil. Anti-anxiety drugs including Ativan and Xanax treat emotional turmoil not ear related issues.
Some doctors champion Neurontin / gabapentin, Tegretol / carbamazepine, Klonopin / clonazepam and Lamictal / lamotrigine but without evidence of merit. The same applies to betahistidine, anti-coagulants and water pills / diuretics such as hydrochlorothiazide or furosemide.
Unfortunately low power lasers, acupuncture, assorted herbs, ginkgo biloba, melatonin, vitamin b 12, magnesium, zinc and candling similarly lack substantial value when compared against placebo response.
Widespread prescription of expensive hearing aids continues even in the face of studies demonstrating people on the waiting list to obtain hearing aids do as well as those receiving them.
Sound therapy with hearing aid-like devices became popular in the late 1970s and allegedly masks the tinnitus. Initial enthusiasm however waned. Of course the exotic sounding fancier TRT or Tinnitus Retraining Therapy, combining sound generators with counseling, provides hype without hope. A similar situation exists with brain stimulation by transcranial magnetic devices.
Cognitive Behavioral Therapy, relaxation therapy and biofeedback remain popular mostly because of the purported benefits and their holistic appeal. None of these interventions offers a positive outcome.
Surgery should be avoided except in the very rare instance where a vascular lesion exists. In the past surgeries were performed to sever the acoustic nerve primarily in people with Meniere’s disease. At times this actually worsened the condition since tinnitus originates within the brain not within the ear.
Cochlear implants may be helpful in extraordinarily limited situations.
But not everything remains bleak. Now with our firmer comprehension of the basic underlying pathophysiology of tinnitus, a scientific approach will ultimately provide specifically directed therapy matched with the primary defect. Until now our approach to the problem lacked merit. It resembled the old adage: throw enough mud at the wall and some of it will stick. It’s time for appropriate, sound pharmacotherapy for this nuisance condition that sometimes bedevils it’s sufferers.