The Search for Why?
Tinnitus is the ultimate symptom of some otherwise undiscovered ?something else.' In many ways, it's like a stuffy nose in that you can tell your doctor about it and he will check down his list...
"Got a cold?" he will ask.
"No," you reply.
"Been crying a lot lately?"
"Eating a lot of wheat?"
"Been stuffing pencil erasers up there?"
"Well, I'm sorry, I can't find anything that would be causing your stuffy nose, you'd better go home and just get used to it."
Established medical opinion has left millions of people feeling abandoned, frustrated, and lost in a claustrophobic world of relentless noise. The last true sanctuary, the mind, has been invaded. The impact on quality of life can be devastating.
Strangely enough, this is what I found really liberating, the fact that traditional medicine has hit a wall.
When we go to a doctor we want them to ?Fix it." Just fix it. I'll spend any amount of money I can if you just fix it. Perhaps someone has to come up with something first that no one else can just fix. Maybe we are pioneers, self-explorers in the true last frontier. Or perhaps I have become a romantic philosopher and can offer you nothing you really want to hear right now. I only feel in my breath and bones that if I can do this, if I can find the quiet for longer and longer periods, you can, too.
What is Tinnitus?
Seemingly relentless sound in the ears and head; buzzing, popping, hissing, roaring, clicking, ringing, and whining are the most common descriptions. The first days are spent vacillating between expecting it to stop at any time and the ever-increasing fear that won't. Concentration and relaxation are the first things to go, beginning a vicious cycle of fatigue compounded by stress, leaving the sufferer even less able to either cope or recover. Social interaction is abruptly curtailed?verbal communication with others is just too much effort over the roar?resulting in feelings of profound isolation. Normal leisure activities like reading, watching television or listening to music are invaded by the ever-present noise. Earplugs can be essential in preventing further sound-induced damage to the ear, but can cause the perceived symptoms to worsen since they block ambient noise and isolate the sound of Tinnitus in your head, making it more noticeable.
It can feel as though the privacy of your mind has been breached. There seems to be no safe place to go, nowhere to run, and less and less hope for change.
The two most important things you can do in the early days are to make an appointment with an Ear, Nose and Throat (ENT) physician and not panic. It could be something as simple as a build-up of earwax or a sinus infection. Really. If, however, the doctor finds no mechanistic cause for the Tinnitus and sends you on your way to deal with it as best you can, You are not alone?
An estimated 45 million people in the US, UK and Europe have some sort of noticeable Tinnitus and at least half that number find that it profoundly affects their daily lives.
In some 10% of cases, the Tinnitus diminishes on its own several weeks after onset with no formal treatment. You could be one of those people. Things can always change for the better just as quickly and easily as not.
One of the fascinating things about Tinnitus is that both the medical community and Tinnitus-experiencers themselves are divided in their opinions regarding where precisely the sound either originates or is perceived. One group says it is caused by trauma to the ear itself, the other is convinced it is either generated or reflected by the auditory, limbic and/or amygdalic regions of the brain.
Tinnitus is usually classified as either objective or subjective. Objective Tinnitus is the rarer of the two and consists of head noises audible to other people in addition to the sufferer. The sound can be caused by vascular anomalies, repetitive muscle contractions or inner ear structural defects and are generally external to the auditory system. An examiner can hear the sound heard by the sufferer by using a stethoscope. TMJ, openings of the Eustachian tubes, or repetitive muscle contractions may also contribute. Pulsatile Tinnitus can be caused by the flow of the carotid artery or the continuous hum of normal venous outflow through the jugular vein and is experienced exactly as named, a pulsing sound sensation. It could be a sign of increased intracranial pressure with additional neurologic abnormalities. The sounds may arise from a turbulent flow through compressed venous structures at the base of the brain.
Subjective Tinnitus may occur anywhere in the brain and/or auditory system and is much less understood, with the causes being many and open to debate. The subjective form is not audible to others. Any area between the ear canal and the brain may be involved.
In any case, every person's experience is unique. The field is wide open to new discoveries. Most of those discoveries are made by people who are living with Tinnitus every day. As in when a person suffers from pain, the experience of Tinnitus is entirely individual and subjective. If you care to consider it this way, there is great freedom in this. For possibly the first time in your life you are in a place to explore exactly what works and does not work for you, what brings you relief and what makes you stronger. You stand to gain valuable skills that will carry you through any experience you may encounter in the adventure of your life. All it takes is self-belief and the desire for change.
What Causes Tinnitus?
This is the great question concerning both the medical establishment and individual sufferers.
This section explores the mechanistic approach favored by current research and seems the best place to begin this journey of self-discovery.
The number one cause of Tinnitus cited by both medical professionals and Tinnitus-experiencers alike, is either exposure to sudden loud noises or progressive hearing loss due to age. It can be a sudden shock from an explosion or blast or sustained extreme exposure from the sound of clubs, concerts, traffic, alarms, drilling, noisy gatherings or, simply, the passage of time and the warranty on your ears reaching the 100,000 mile marker.
The first effect of extreme sound-induced damage is an unusual feeling of fullness or pressure in the ear, similar to being under water. A high-pitched whine or drone usually accompanies the sensation. The full feeling usually subsides, though the ringing tone stays, and in some cases, increases.
Hearing is a series of events in which the mechanism of the ear converts sound waves into electrical signals that are interpreted by the brain as distinct sounds. The three delicate parts of the ear, outer, inner and middle, act in sequence to translate and communicate these signals. A dysfunction in any single part not only affects the final nerve impulse, but the way in which that impulse is interpreted by the brain.
There are three tiny bones in the middle of the ear called the ossicles. They are named the malleus, the incus and the stapes, or by the names usually taught in school, the hammer, the anvil and the stirrup. Acting with the eardrum, they amplify the vibrations, transmitting them to the fluid that fills the snail-shaped cochlea. This fluid moves the top portion of hair cells lining the cochlea, initiating the changes that lead to the production of nerve impulses. These impulses are then interpreted by the brain as sound. Different sounds move the hair cells different ways, allowing the brain to interpret them as distinct.
Sound is measured in units called decibels. Normal conversation is around 60 decibels, the humming of a refrigerator (unless it's my annoyingly loud fridge) is 40 decibels and city traffic can clock in at 80-120 decibels.
Most scientists maintain that sounds of less than 80 decibels are unlikely to exacerbate hearing loss, though it is commonly believed amongst people suffering from Tinnitus that there are ?weak? and ?strong? ears, weak ears being more vulnerable to damage.
When damage occurs through noise exposure, and a recovery is experienced within 16 to 48 hours, the period of loss is called a temporary threshold shift. It is believed that a succession of these shifts can ultimately result in permanent hearing loss and/or Tinnitus. Repeated exposure to noise from loud concerts, industrial production or gunfire, anything at a decibel level that causes some immediate discomfort, is cited as a contributing factor.
Recent research shows that hair cells are capable of rebuilding their structure from top to bottom over 48 hours, thus accounting for the temporary threshold shift. When the damage is so severe that it overwhelms the self-repair mechanism, permanent hearing loss occurs.
While all this is happening in the inner ear, what is going on in the brain? Welcome to the "Centrally Based" theory of Tinnitus.
According to this theory, the damaged ear is often the trigger of Tinnitus, the sound not originating in the ear itself, but rather in the way the brain interprets the different (or lessened) signal from the cochlea.
The damaged ear can cause the brain to act as the source of the sound when the brain responds to the altered input from the ear by altering its own activity. The suggestion is that Tinnitus-related brain hyperactivity, once triggered, becomes an independent phenomenon.
The brain, either in an attempt to ?fill in the gaps? from progressive hearing loss or replaying a pattern imposed by sudden, explosive noise, continues with its hyperactivity. It does this because it has seemingly permanently ?rewired? itself in response to the ear damage. This is why severing the entire auditory nerve, which leads from the ear to the brain, often fails to cure Tinnitus. In some cases, the now completely deaf patient is still left with persistent ringing and no ability to mask the sound with ambient noise. This is a grim possibility to consider. Similarly, laser treatments or a cochlea transplant could be no more effective than cutting the auditory nerve, because they would not address the possible source of the perceived sound?the brain itself.
Studies using positron emission topography to chart brain activity have recently confirmed something that researchers have long suspected: in certain people, Tinnitus activates both the auditory and limbic (emotional) centers of the brain. The experience of Tinnitus can raise your blood pressure by inducing anxiety. Sounds trigger emotions, which is why a person can hear a piece of music on the radio and hardly even notice it, while the next selection may bring them to tears. It's all just different sounds, though the emotional response can be very different depending on the exact frequency or combinations of frequencies.
In people who have either habituated or never had a problem with Tinnitus, the sound is like elevator or ambient music?they don't really notice it at all.
In certain horror films, a stringed instrument is often employed to play a sustained high note to heighten suspense. Tinnitus experiencers perceiving a similar sound in their heads may translate this into a sense of dread or anxiety, possibly a trained response by their body to past stimuli. The anxious feelings may then contribute to a greater level of stress, further contributing to the volume or duration of the perceived Tinnitus.
According to the Centrally Based theory, Tinnitus continues, unless one somehow causes re-patterning, or cortical reorganization, in the affected areas of the brain, thus undoing the effects of the trauma. This re-patterning is most commonly addressed through Tinnitus Retraining Therapy (TRT).
Peripheral (ear-based) Tinnitus is still a possibility. A signal is sent to the brain from damaged ear cells and is then interpreted by the brain as Tinnitus, though the centrally based theory is where current research is headed.
In a 1998 study by Dr Alan Lockwood and Dr Richard Salvi at the University of Buffalo, brain activation was observed corresponding specifically to Tinnitus. They found that when Tinnitus was momentarily increased in one ear due to jaw movements, altered activity was only seen on one side of the brain. While normal sound introduced through one ear would activate both sides of the auditory cortex, Tinnitus appears to activate only one side. This indicates that the Tinnitus signal is fundamentally different from peripheral noise sources, and Lockwood and Salvi concluded that it must be centrally based.
It seems that some people deeply dislike the thought of their brains being "rewired? and thus tend to gravitate towards the theory of hair cell damage as the source. Conversely, others are frightened of the seeming permanence of hair cell damage and turn with hope to the possibility of re-patterning the brain's perception of sound.
Both scenarios have validity at this point in medical research. Everyone has some hair cell damage and everyone probably has some sort of cortical re-patterning; in terms of both peripheral and central interpretations, it's most likely not a matter of either/or, but more a question of where you believe you are that determines how Tinnitus affects you.
At a certain level, the brain is re-patterned every moment?uncomfortable experiences can be re-interpreted if given the right stimuli. It is also important to realize that your individual experience of Tinnitus at any particular moment does not signify either permanency or increase of the symptoms.
The latest research in peripheral causes seems to be converging around the Dorsal Cochlear Nucleus Disinhibition hypothesis (DCND-H), which maintains that damage to the cochlea leads to reduced neural input for the brain's auditory system. The dorsal cochlear nucleus (DCN), is the first processing station in the central auditory system, contributing significantly to sound processing. Reduced neural input to the DCN results in its becoming disinhibited; put simply, it continues working spontaneously, even when there's no signal for it to process. Disinhibition of this organ is also observed following non-auditory problems involving TMJ disorders and whiplash. The neurotransmitter substances that normally inhibit certain neural activities show reduced action. This absence of inhibition allows increased spontaneous activity of the affected regions of the auditory pathway. Having been sent to the auditory cortex via another crucial organ, the inferior colliculus, this hyperactivity in the DCN is interpreted as Tinnitus.
This may lead to the identification of a final common pathway for the vast majority of Tinnitus cases. This theory focuses on particular organs and locations, and should ultimately include specific neurotransmitter substances as well.
Standing fast against this theory is the supposition that if the process described above is initiated by any and all damage to the cochlea, Tinnitus would accompany hearing loss far more consistently than it does.
It's a mystery. It's a mystery compounded by the fact that a person could have very subtle damage to the mechanism of the ear which has no conscious impact on the capacity for hearing, but which is nonetheless significant for the brain because it slightly alters neural activity. A particular person suddenly perceives an annoying sound, while the next person with a similar level of damage is unaffected.
The correlation between Tinnitus and hearing loss may be due to a specific type of damage, or possibly there is some specific brain chemistry in certain individuals, predisposing them to Tinnitus in response to peripheral triggers.
This can lead us back to the earlier point that Tinnitus is the ultimate symptom for some as-yet-undiscovered ?something else," and that each person's experience is based on factors completely unique to them and their subjective experience.
I would now like to proceed from the mundane to the possibly super-scary reasons for Tinnitus causes and triggers.