Noise-Related Tinnitus: Brain Remapping Experiment

@HomeoHebbian

Based on that study where they "created T" by wearing the plug on one ear for 24/7 ..I was wondering if we could consider the following approach, and please let us know what you think of this.

I am basing all this on a situation caused by a clear cut inner ear injury/noise trauma situation.. - nothing else. No stress/anxiety/unknown etc.. causes

If the brain tries to recreate some lost frequencies because it remembers that there was signals coming from the ear before..maybe we can trick the brain into forgetting about those lost frequencies.

The experiment would be as follows:

Recreating the one plug study, we wear the plug in our worst ear for 24/7 maybe a few weeks more than the study, if required. The goal is to get a new, louder tinnitus.

Now the brain thinks its a lot worse than before, and T is louder. The silicone plug cuts the high frequencies well which mimics a major noise induced hearing loss.

Then maybe some time later, some habituation happens and a T decrease follows, as the brain re-maps to the further lack of high frequencies to that bad - plugged -ear.

At this point, we remove the plug from the ear and the brain is tricked into believing the high frequency loss is cured which could lead to a permanent cure of T....how much can the brain remember how if was before the acoustic trauma which was well before the added loss by the plug ?

Maybe this is our free-of-charge, no-side-effects permanent ticket out of T-Land ?

Maybe this is why no one studied it, as there is really no money to be made out if this..besides the cheap silicone plug...no fancy filters required we want to block as much HF as possible.

The "New T" would be very loud and uncomfortable for the duration of the remapping but if this means a permanent reduction at the end of the tunnel, so be it.

We know that some of the sound therapies do work but but those are not very effective because its impossible to listen to the notched sounds for 24/7 and for weeks.

Listening to sound therapy in order to re-program the brain for 16 hours a day , then a few hours of normal sound is perhaps enough to erase all reprogramming done for the day therefore the effectiveness is not impressive...you are back at square one everyday.

 

Good idea but...

Not sure about that. That would mean a sudden hearing loss is always followed by tinnitus, which is not the case. The volume of T is not linked to the severity of hearing loss either.

When you plug, you feel a louder T because nothing can mask it.

If T is created by the loss of synapses following a noise injury, the brain won't receive weird signals if you just plug and won't feel the need to make T louder.

In my opinion, you will just return to base level when you remove the plug.

If we follow your logic :
- mild hearing loss : mild T
- loud hearing loss : loud T
- back to mild hearing loss : back to mild T, the hearing loss is still there, the brain knows it because it receives nerves signals that tell him that

I would also be worried about an infection, keeping a plug for weeks... Besides, I don't think a brain reprogramming happens in a few months time.

But I'm not saying it's not worth a try.

 

Here is the study link

https://www.tinnitustalk.com/threads/plugging-the-ear-leads-to-the-perception-of-phantom-sounds.975/

We know that some sound therapies have a positive effect on T perception - even though the nerves/cells have not improved. But those therapies are hard to implement effectively.

This plan is similar to a sound therapy in a way, but its more effective as its 24/7 and free of charge.
Yes you would need to remove the plug for short times regularly and clean the ear canal or use anti-bacterial cream on the plugs etc..but again, they did it in the study so its possbile

 

So are you going to try it ? Maybe just a week first ?

 

I may try it - but I was hoping to get more discussion on this first.

Yes after a week it would be interesting to remove the plug and see what we get ..and maybe then try longer if this points to to right direction in terms of T reduction.

At some point the brain is not going to remember those lost signals, that's why many people with very slow progressing hearing loss don't have T.

The worst is a sudden change/acoustic trauma where the brain has no time to adapt and remembers what it was before.

 

I tend to agree with Foncky, it sounds most logical you will just return to your original state after wearing the earplugs.

I think there are two things involved in Tinnitus generation/severity:

• Tinnitus caused by actual damage (your base level).
• Increased tinnitus perception due to stress/anxiety (this is added on top of your "damage" tinnitus and depends on your emotional state).

If you start to wear earplugs 24/7, your tinnitus will be perceived louder due to the earplugs. This in turn might lead to emotional responses making the Tinnitus perception even louder. If you take out the earplug you will simply return to the "damage" tinnitus state once you have calmed down.

You will however never undo point 1, the damage tinnitus, unless this damage is recovered (hence it is a symptom). You can retrain the brain to a certain extend, but this will mainly retrain your perception of the damage tinnitus (not the generation of the tinnitus in the first place). The tinnitus will still be there if you look for it.

That's what my understanding is anyway... Of course I might be completely wrong, as no one knows anything for sure with this mysterious affliction. I would absolutely love to be proven wrong...

 

Vinnitus you said it better than I did. That's exactly what I think. I want to be wrong too.

T might not only be the result of a lack of signals : weird signals are also sent to the brain after cochlea damage.

 

A lot of people have hearing loss with major hair cell damage but no T - In fact the majority of people on this planet have some degree of hearing loss AND not T.

A sales guy in my office cannot even hear 8khz or higher at all - but I can.

But he has zero T.

Because his loss happened very slowly over decades.

The key is to reprogram - or in this case trick - the brain to not notice the lost frequencies and to not re-create those.

Hence the sound therapies..

 

I know a hunter who became deaf in one ear after a single gunshot with no protection. No T.

Just try it Bobby, see you next week !

 

Yes - exactly !...you can have major hearing loss and no T .

Our stupid brain thinks it needs to re-create those lost frequencies for some reason..there is no reason really..

But not every one brain is the same..some need more help reprogramming, some just forget and move on like the hunter guy you mentioned.

maybe @HomeoHebbian can throw his opinion as well, he is a brain specialist I believe.

 

Yes, but I believe the work of Charles Liberman revealed that there are different types of hearing loss. You have the hearing loss where sensory hair cells are damaged or broken and you have the type of hearing loss where the connections (synapses, nerve terminals) between the hair cell and the auditory nerve are damaged.

As a result, I now think it depends on the type of hearing loss you have whether you will develop Tinnitus or not. If you have hearing loss due to losing hair cells, this might not cause Tinnitus per se (losing hair cells is a natural process anyway). If you however lose hearing due to damaged synapses, this might be responsible for Tinnitus.

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0162726

This makes me think... What might be possible, is that a high decibel event causes an input surge just before the synapse gets damaged. The central gain in the brain is adjusted as a consequence of this elevated decibel input. As there is no stimulation anymore at the damaged input synapse after this event, the gain increase in the brain gets "stuck" for that frequency, possibly causing the perception of Tinnitus... I believe that is what it says here. I wonder if that frequency can be "unstuck" if we do not have the sensory inputs anymore to reach it...

 

I think you makes this "sound"(!) a lot more complicated that what it is.

The fact is that the plug study was able to re-create T and without any of the damage in the inner ear.
So its clear that sound which cannot reach the brain MAY result in T but not for everyone.
Some brains just forget and move on, some other get stuck with T.
Not everyone with major loss suffers T so its possible to be off T even with major damage..
My idea was to get the brain to forget and move on - that's what the sound therapies try to achieve with partial success.

I guess we have to try this out ourselves..at least this is better than any of the psycho meds out there with temporary effect and other drugs with side effects ..and it costs nothing.

 

I think I see what you are after, Bobby. Crank up the T by wearing an earplug and then hope that the new 'steady state' T is lower than it was before once the plug is removed and the central gain is turned down. Seems to me that the root problem of a reduced input from the damaged ear(s) remains and that the gain will settle back to its original position. The interplay between the cochlea and the brain's 'central amplifier' is well described by the canonical negative feedback loop - https://en.wikipedia.org/wiki/Negative_feedback. These systems are self-organizing, very robust and hard to push out of the set point by adding removing input. I understand the logic of your idea but I think the best bet is to a) change the 'set point' of the central amplifier or b) increase the input from the damaged ear.

As for physicians and scientists pooh-poohing any remedy that wouldn't allow them to cash in... nah, I wouldn't say that is a big factor. Tinnitus is viewed as one of the 'premier problems' in our field so I think fame and glory would motivate people to set monetary gain aside. At the same time, I think you are right that there is a major bias towards devices and drugs. More than anything else, this is the zeitgeist of the age. We live in a time when drugs have worked extremely well for so many conditions that they are viewed as a panacea. I myself am skeptical that a drug could ever be developed that would pinpoint the generator of the phantom sound. As for devices, well yeah, otolaryngology is a surgical subspecialty and removing/installing things is pretty much their worldview.

Why don't you try your approach and see how it works? I think you noted the risks (increased T while wearing the plug) and I played the role of the curmudgeon and told you why I didn't think it would work. But I would love to proven wrong. It won't be terribly scientific but you could mark down your T severity on a scale of 1 (not audible) to 7 (intolerable) twice a day during the course of your "experiment". My advice (though I am NOT a medical doctor and my advice should not be taken as anything more than another voice from the peanut gallery) would be to skip it because it will make your T worse at first and then no better than it was later.

 

I think you are both on an interesting point. I agree with Bobby, in that the brain doesn't distinguish between a loss of input from the ear that originates from the loss of hair cells or cochlear synapses. Loss is loss. And reduced input is the driving force behind increased 'brain gain'.

On the other hand, Vinnitus also has a good point in that cochlear damage from noise exposure differs from cochlear damage from aging or ototoxic drugs at the moment of trauma. Blast injury or intense noise exposure drives pathological activity during the period of cochlear decline, whereas cochlear decline with aging or certain types of chemotherapy drugs (for example) does not incur the same pattern of pathological activity. We (hearing scientists) don't really understand to what degree tinnitus arises from the abnormal patterns of activity during the period of noise exposure versus the aftermath of having lost a lot of cochlear input.

I take the simpleminded view that it is the 'steady state' level of reduced signal coursing through the auditory nerve that drives the pathologically over-powered central amplifier, but maybe there is more to it. The most common way to reach the land of chronic tinnitus is through noise exposure so maybe there something special (i.e., particularly terrible) about what is happening in the auditory pathway during the period of intense noise. Off the top of my head, I can't think of any study that has ever attempted to track activity in the brain during noise exposure. It's not an easy thing to do.

 

The current thinking isn't that the brain is "recreating the lost frequencies", per se. Think of it this way: the cochlea is played out like the keys of a piano. Low frequencies on one end, high frequencies on the other. The keyboard-like arrangement (which is called tonotopy) is recapitulated at each of the various stations of auditory processing in your brain. Now let's say that someone takes a hammer and destroys the six highest keys on the cochlea's keyboard. What do neurons positioned in that portion of the brain's keyboard do? They aren't getting any more input from the keys that have been destroyed. Well, they start cranking up their internal gain, making themselves more sensitive to inputs from the neighboring keys and more sensitive to the background 'hum' from their local neural neighborhood. Now when you strike the keys just adjacent to the damaged keys they elicit a lot more neural activity than they used to. What's more, the neurons that used to encode inputs from the damaged keys are now both hypersensitive and hyperactive. Paradoxically, destroying their section of the keyboard has made them more active, not less active.

The processes in our brain that shape our conscious awareness don't know whether neurons were activated by a sound in the environment or whether the activity was internally generated. For example, if you pass weak electric current into the brain of a patient undergoing a neurosurgical procedure they will report vivid hallucinations that depend on what part of the brain was stimulated. So, when processes that shape our perception of sound 'see' a whole mess of neural activity in the high-frequency region of the brain's keyboard...they do their job and induce a conscious percept of the corresponding sound frequencies.

This is a pretty accepted view of how the most common tinnitus, a high-frequency tone/whistle arises. But like unhappy families, no two forms of tinnitus are quite alike.

 

Yes, the brain will turn up the gain if it notices the auditory input is reduced (by ear plug or otherwise). If you remove the ear plug, the auditory input is restored and therefore the gain can be adjusted to a lower level. In the case of a damage-event however, there is actual damage to the sensory inputs, preventing the brain from turning down the gain.

This is similar to the 1953 Heller/Bergman experiment where they put healthy people into a silent room and they started to notice "Tinnitus". What they in fact might have noticed, is their brain increasing the gain and looking for auditory signals, giving them the perception of Tinnitus. The conclusion often reached after referring to this study; "everyone has tinnitus" is however too simplistic. We, as tinnitus patients, perceive this increased gain even in normal environments due to sensory damage.

So yes, the conclusion should actually be: "everyone has (the possibility to perceive) Tinnitus" because everyone has this gain mechanism in their brain and in certain circumstances they can trigger it. For Tinnitus patients however, this is triggered indefinitely due to sensory input damage. This sensory-input damage level is where you will return after taking out the earplugs.

In conclusion; I don't think this ear-plug approach will work, but if you want to try it I will be interested to know the results. And again; I will be very happy to be proven wrong, as it might mean there is a way out of this misery. Good luck and keep us updated please.

 

This is what techniques like Acoustic CR Neuromodulation and Vagus Nerve stimulation try to achieve, right? Do you know of any data about the long lasting effects of these types of treatments? Some patients reported success with it. If this hyperactive neuron theory is true, I wonder if the treatments will result in temporary changes or that the neurons might become hyperactive again some time after the treatment has finished... Maybe peripheral malformed input will put them back in their old behaviour? After all, the initial damage has not been resolved and Tinnitus is a symptom of it.

I have been looking for data on this matter, but I can hardly find any... Maybe it is too early in the game for this?

I agree. I think the only treatments that will reliably resolve Tinnitus, are the treatments that take away the root cause. The other treatments are "symptomatic treatments" in my opinion, and might need repeated treatment in order to keep working. They might provide relief (of course very welcome relief), maybe temporary, but they will not fix the issue. The only ways to permanently sort this (I think) will be the following.

• Suppressing the proteins in the inner-ear that prevent hearing regeneration for a while, until the damage has been restored.
• Supplying the inner-ear with stem cells to regenerate the needed cells from them.
• Finding other ways to stimulate the areas responsible for the lost frequencies (some people reported their Tinnitus disappeared after getting a Cochlear Implant).

All these methods will be able to restore auditory input to the brain. This will not cure tinnitus directly, but will cure "hearing loss" and maybe tinnitus as a consequence of that.

 

So I have to get my earwax cleaned out every few months and have noticed a continuing improvement in my bad ear each time they remove the wax. Strangely I used to never get this much wax buildup before my T.

 

@HomeoHebbian

In your opinion is there any potential therapy by altering the electrical activity in the brain?
I'm especially interested in sodium and potassium ion channels and their effect on tinnitus. Trobalt (a potassium channel opener) appears to temporarily reduce tinnitus while lidocaine (a sodium channel blocker) also reduces tinnitus temporarily in some people. I wish I knew more about neurochemistry, but from my understanding potassium ion channels have a calming effect on neurons and sodium channels have an excitatory effect on neurons. Is this correct?

If you were to suppress the sound for a long period of time, would it be possible to reverse some of this neuroplasticity? One thing I don't understand is why some people with hearing loss get tinnitus and why others do not get tinnitus. It seems to me tinnitus arises from an inappropriate brain reaction to hearing loss (often sudden hearing loss). If that is the case, can stress or certain medications alter the way the brain reacts to hearing damage?

Can this extreme hyperactivity recruit other non-auditory brain areas?

I have a lot more questions, but I'm half asleep so I hope I'm making sense.
I appreciate your input in this forum. Hope you stick around.

 

Sure, electrical activity is the lingua franca of all brain areas, no matter whether they control hunger, weigh ethical dilemmas or create annoying phantom sounds that piss off their owner. It is widely understood that the fundamental pathology of tinnitus lies in the patterning of electrical surges in the brain. So, change that and you can create/eliminate tinnitus.

Yes, sodium and potassium are ions (molecules that carry a charge) and are two of the essential building blocks for creating the electrical excitability of the brain (and the ear...and the heart...). These molecules are ubiquitous so changing the gross levels of sodium or potassium is unlikely to a successful strategy for tinnitus relief. And I think you mislead by someone who told you that there is any connection between a type of ion channel and an emotional state like calm, agitated etc. There is no reason to believe that is true. Neurons are equipped with pumps that diligently pump sodium out of the cell and keep potassium inside the cell when the cell is at a resting state. When a cell "fires" those ions change their concentrations (sodium rushes in and potassium out) and then sisyphus most resume his work of establish the correct ionic balance with those pumps once again.

Why do some people get tinnitus and others do not? That is the $64,000 question. One explanation is that it boils down to the number of intact 'channels' you have that convey acoustic signals from hair cells to neurons in auditory processing centers of the brain. If you lose channels, either through hair cell death or nerve fiber loss, the brain compensates and the process of compensation puts you at risk for tinnitus. Standard hearing tests are only sensitive to certain types of ear damage. That explains why people can have vastly different tinnitus outcomes with the same audiogram (and vice versa). Another explanation is that the problem lies more directly in the brain. More specifically it can be attributed to a process called -> homeostatic plasticity <-. This is a cellular process that allows neurons to return to a 'set point' of activity. Like the thermostat in your house, neurons sense their own metabolic activity and adjust their sensitivity up or down until they get their internal temperature just right. Tinnitus might be a failure of this homeostatic process. The neuron keeps turning its sensitivity up and up and up and then at some point, it crosses a point of no return and can't down-regulate its excitability.

Hope that is enough to chew on for a while...

 

I did not mean the type of ion channel dictating an emotional state like calm and agitated, what was getting at was cellular excitability. I had assumed that opening up potassium channels down regulated neuron excitability. Thanks for the explanation.

You are right, potassium and sodium channels are so ubiquitous that relief from tinnitus won't come without side effects elsewhere in the body. Some here at tinnitutalk have gotten temporary relief from tinnitus on retagabine, but not without side effects. There have been a few that claimed they got a lasting reduction after discontinuing the drug which I find interesting. Still those who had a lasting reduction are outweighed by others that had bad side effects with no lasting improvement.

I have heard that the hyperactivity of tinnitus following an acoustic trauma may recruit other non-auditory brain areas, like those that effect stress and attention so not only do you get a constant sound, but you get a constant sound that can't be ignored.

Homeostatic plasticity, that's something I'll have to mull over. That does bring me back to the question... can certain medications alter the way the brain reacts to hearing insults? A number of people on this forum blame bupropion for their chronic tinnitus, yet the drug is not listed as ototoxic. Can medications like wellbutrin and benzos indirectly affect homeostatic plasticity?

 

I feel like this is a stretch. Is LLLT not working for you @Bobby B ?

 

Technology, science, and medicine *will* conquer this and other maladies.

You have companies like Google, IBM, and major pharma companies on the case.

The thing to keep in mind is that the human brain contains 100,000,000,000 neurons. It *will* get done and major medical breakthroughs will occur at all levels. However, it will definitely take time.