Why Tinnitus Is Bothersome

 

I want to speak for a while about what is physiologically happening in the person with bothersome tinnitus.

And understanding what's happening in your brain, or what's happening in your body, is an important clue to help us find better ways to manage bothersome tinnitus so that we can allow our brain to habituate to this benign body sensation.

And so, you know, in my practice, I like to look at other body systems to help me understand other body systems.

By other body systems, I mean we are one system.

And so it stands to reason that looking at one body part can help us understand another body part.

And so today we're going to talk about phantom limb sensation as a way to better understand what might be happening in the brain of the person with bothersome tinnitus.

So phantom limb sensation, for those who have not known anything about that, is that when humans or animals lose a body part, the brain can experience it as if the body part were still there.

And oftentimes it can be excruciating pain.

Sometimes it's warmth, coolness, a tickle, tingling, what have you—some sort of sensation.

But the brain seems to create a scenario where you can feel as if that body part is still there.

And so let's use my hand as an example.

Okay?

So let's pretend I cut my hand off.

Boom.

Horrible thought, but let's pretend.

And so when my hand is cut off, my brain—my hand is literally here, but my hand is really here.

Okay?

So because this is where the sensations from the hand go to, this is where the commands to the hand come from, and this is where the memories of this hand are, right in my brain.

And so in the absence of the hand, let's say I cut it off, God forbid, the brain starts to freak out.

And the brain doesn't like gaps.

It loves to fill things in.

I mean, our blind spot, for those who know that we have one, our brain fills in that blind spot so that we can see a full picture without the hole in what we're able to see.

So anyway, the brain loves to fill things in.

And so in the absence of the hand, the brain starts to say, "Wait a minute. Where's my hand?"

It starts to freak out because it's always had a hand.

I was born with a hand.

I use my hand all the time.

It has to be here.

So the brain starts to search and search and search, and it really starts to freak out because it can't find the hand.

And it has to be here.

It's always been here.

So the brain searches and searches and searches, and in that neuronal firing around those areas, boom, it creates the sensation as if the hand were still there.

Okay?

So we know that is phantom limb sensation.

And again, it can be tingling, it can be kind of itching, it can also be incredible pain.

Now let's look at another body part: the ears.

And maybe we can learn from phantom limb sensation to give us clues as to what's happening in the brain of the person with bothersome tinnitus, or tinnitus per se.

So let's go to the ears.

We have—I'll break the ear into three parts.

We have the outer ear, which is right here.

We have the middle ear, which is from the eardrum to the oval window.

And then we have the inner ear, which is basically, you know, the last stop before sound goes to the auditory nerve, and then it goes to the auditory cortex, and we get the sensation of sound.

And so there's an organ in the inner ear called the cochlea.

And now the cochlea is shaped like a snail shell.

Okay?

So imagine a snail shell.

It's kind of a tube that turns in on itself.

Okay?

This is the cochlea.

And the inner lining of the cochlea, we have these tiny little hair cells that line the inner lining of the cochlea.

Now let's take the cochlea and let's unravel it.

Okay?

So imagine I've just unraveled the cochlea so that it's flat in front of us, and it has all of these hair cells on the inner lining.

And now when sound comes through the ear, it creates a sensation—the waves will hit these hair cells and make them move, which transmits then an electrical signal to the auditory nerve, which goes to the brain.

And that's how we perceive sound based on the frequencies of the hair cells that are stimulated.

So here we have the cochlea in front of us, and we have these hair cells.

And I find it interesting because the high-frequency hair cells are here—the high-frequency hair cells—and the low-frequency hair cells are down here.

And just like a piano, or a tonotopic map, we have every hair cell note in between, just like a piano.

And so I often chuckle because here we think the Italians invented the piano, when we've all been walking around with a piano inside of our brains the whole time—or inside of our ears the whole time.

But anyway, I digress.

So we have this cochlea here that's flat in front of us.

Now let's start at the low notes, or at the low-frequency hair cells, and let's roll it back up.

So roll it, roll it, roll it, roll it, roll it.

Here we have the mouth of the cochlea, which corresponds to the high frequencies, and deep, deep inside we have the low-frequency hair cells.

Okay?

So let's think about the physiology, or the anatomy, of the ear.

In that, waves of air come to the ear and create sound.

We said before these waves will stimulate the hair cells, and then will give information to the auditory nerve and the auditory cortex about what frequency the wave has created.

So over our lifetime, air comes through the ear as waves.

And look what happens.

The mouth of the cochlea has these high-frequency hair cells, and over time—wear and tear, the accumulation of birthdays, what have you—we notice that these high-frequency hair cells are the first ones to chafe off.

Now, the low-frequency hair cells are very, very well protected, deep, deep, deep inside the cochlea.

Now, things like Ménière's disease or other ototoxic reactions, or genetic reasons, the low-frequency hair cells can be affected.

But in the majority of people, it's high frequency because they're the most vulnerable.

They're the ones that are closest to these waves of air that are coming in from the external world, you know, to be processed by the brain.

And so what happens—and it's so common, in fact, that we have a word for it.

It's called presbycusis.

It's called hearing loss with age.

And what happens is those high-frequency hair cells start to chafe off.

Okay?

And so let's go back to phantom limb sensation.

We know that in the absence of the hand, the brain freaks out and starts to search and search and create the sensation as if the hand were still there.

Now let's go back to the cochlea and these hair cells that are chafing off.

The brain starts to say:

"Wait a minute. Where's that frequency? It has to be here. I've always heard that frequency. I was born hearing that frequency. I've heard that frequency all the time. It has to be here."

So the brain starts to search and search and search and search.

And it starts to really freak out because it just can't find the frequency.

So it searches and searches and searches and searches.

And in that, it's creating the stimulation of those neuronal endings.

And then, boom, it creates the sensation of tinnitus that people experience.

So essentially, there's nothing broken.

Okay?

There's nothing really to fix.

It's the brain is searching for a sound that it's no longer receiving.

That essentially is what tinnitus is.

The brain is searching for a sound that it's no longer receiving.

And when somebody gets locked and loaded on that missing sound and walks around kind of searching for it and connects it with fear, then it can stay, again, front and center for 20 million Americans and create a situation where there's an awful lot of suffering around this otherwise benign body sensation.

And so in the process of habituation, the brain needs to reappraise tinnitus for what it is: a benign body sensation.

Simply, your brain is searching for a sound that it's no longer receiving.

Nobody's ever died from that.

It's, you know, unfortunate.

Wouldn't it be great if we didn't lose hair cells?

But it's part of this life we live.

And so the brain is going to have to digest that, calm down, and really stop itself from over-searching for this frequency that it's no longer receiving.

And in so doing, it creates that disengagement from fear, and the person is able to shift tinnitus from bothersome to non-bothersome.