Hearing Loss Cures and Neuroplasticity

[DebInAustralia]

Question...

Even if a hearing loss cure is discovered, will tinnitus still be a problem given the plastic changes that have occured???

 

[seal]

I don't think anybody can tell as we don't even know if and how hearing loss can really cause tinnitus and neuroplastic changes are also only a theory

 

[Sound Wave]

That's a good question for which I don't think an answer yet exists...

 

[Steve]

Neuroplasticity is proven in other areas, for example where a person loses one ear or one eye the brain recruits other areas to adapt to the changes. Our brains are constantly rewiring themselves in response to change.

So it does seem to make sense that when we lose input (in the form of a hearing loss) the brain adapts to this and as a by-product we hear tinnitus. But it doesn't answer why only some of us get tinnitus.

If the brain has changed, then it will have to change back again if hearing is restored. I would guess that we have to stimulate the brain in some way to make that change. Maybe over time having full hearing will gradually decrease tinnitus or maybe we would have to listen x hours a day to broadband noise (white noise, rain etc) or something targeted at reminding the brain of the full range of noise that could be heard to encourage the change.

 

[Johno]

Neuroplasticity is some kind of healing proces. But, why then it produces Tinnitus and makes things even worse? A lot of people with damaged hearing doesn't have tinnitus.

 

[Stina]

Neuroplasticity is some kind of healing proces. But, why then it produces Tinnitus and makes things even worse? A lot of people with damaged hearing doesn't have tinnitus.

I think the neuroplasticy theory states that the brains of adults are not as plastic which is why the sound is memorized. g. the brain gets used to doing certain actions and cant change back later although the original cause doesn't have an effect on it anymore. But I dont know why some people dont get tinnitus. It has been stated that the more gray mass one has the more prone they are to, also I think often more naturally anxious people are under risk. the brain creates tinnitus because he thinks that he is in fact compensating for hearing loss. Of course the brain iss not thinking about our emotions though.
I dont think neuroplasticy is a healing process though, I think its just the way the brain is. But Im not a doctor so maybe I havenät fotten anything right.

 

[jchinnis]

There are a lot of research papers that examine auditory neuroplasticity in animals and humans. It is a well-established fact.

Plasticity remains in the adult. One of the practical implications of plasticity in the auditory system is that hearing aids or implants can cause changes which then create a need for adjustments.

Plasticity works in funny ways. The order in which things happen makes a difference. So, losing a bit of hearing one day followed by a different loss later doesn't necessarily produce the same changes in neural "wiring."

It's also the case that there is activity in the auditory system related to discrimination of pitches that involves some rather specific interactions among neighboring neurons. One that is sometimes mentioned here is lateral inhibition. This means that adjacent tones try to suppress one another--a louder tone will be able to suppress its neighbor more, leading to it standing out better. What happens when some specific frequencies are lost or reduced is still a bit of a question in research. Do neurons adjacent to neurons with lost inputs fire more because they are suppressed less?

It is pretty easy to come up with a variety of hypotheses about how tinnitus might emerge from "edge effects" like this. And it seems clear that tinnitus might thus bear little or no relationship to gross hearing loss (such as shown in an audiogram), yet might have a clear relationship to an incredibly detailed map of hair cell loss--and its history/timing.

Not simple or easy!

 

[Littlebailey]

It would seem like the main driver of tinnitus is damage to the all-important ear hairs, and so the brain responds, for whatever ungodly reason, by making those exacts same sounds - phantom sounds - which the ear can no longer deliver to the brain. Just like everyone says. And in a way, I guess is sort of straightforward. Obviously I'm just citing the conventional thinking.

But maybe it's only a certain kind of damage. And gradual, more gentle hearing loss, doesn't induce the ringing response like more sudden, violent noise-induced hearing loss. And the brain is never riled up enough by the loss of tiny, steady auditory input to respond with the terrible ringing. But maybe there's more to it, and only a certain personality type even gets the tinnitus. Maybe if you're a nervous sort, the brain is more on edge, and is more liable to respond with some sort deep-inner brain subconscious panic to this loss of input. And if you're a generally content and easygoing person, the unconscious brain may not panic, and in effect not worry about the missing input due to any cochlear damage. And so you never get the ringing. And when I say 'nervous', I don't mean like, a basket case or anything. Just a little more tendency toward nerves, and a greater sensitivity to potential worry and the like.

Makes sense to me. Though that's obviously the purest of ignorant layman's speculation, as is probably wrong.

 

[bill 112]

I believe once the input is restored the ringing should stop and ive good reason to believe this.I was reading an article in an Irish health magazine about a man who proves this hypotheses.He had lost most of his hearing at birth from sort of virus I think it was.As he grew older his hearing diminished even further and later devoloped T as a result and could hear what sounded like people talking even though he was profoundly deaf.Worried he went to his specialist thinking he had gone crazy but they could provide no answers.Eventually he got a call from a specialist in the U.S who was intrested in helping him.After an examination the doctor came to his conclusion.His diagnosis was that the input from the cochlea was so low that the brain was compensating for the low input of sound by creating phantom sounds and using sounds from the auditory memory as compensation.He was scheduled to receive a cochlear implant after this he reported that his T had reduced by 90percent.He was then given a second implant which is rare considering most people get one.After this it took about 2 months and his symptoms had completely disappeared which is a good proof of concept that once input is restored the T should disappear.I cant find this story yet but il keep looking and post a link.Also there is a similar story on google about a woman from the U.K with similar results she also got two implants check it out.

 

[dan]

The real processing is concluded in the grey matter. It was given the name gray because of its appearance. It has a grey color because of the grey nuclei that comprises the cells. It fills about 40 percent of the whole brain in humans, and consumes 94 percent of oxygen. The neurons of the grey matter do not have extending axons, or long, thin projections of neurons, that send electrical signals away from the soma (another name for the cell body of neurons). Neurons create networks, in which nerve signals travel. From the dendrites to the end of its axons, the signals reproduce in the neural membrane by way of electrical modes. Neurons do not make body contact with each other when conveying messages. The neurotransmitters serve as the medium to connect one neuron to another neuron. The senses of the body (speech, hearing, feelings, seeing and memory) and control of the muscles, are part of the grey matter's function.


The white matter, also known as substantia alba, is a neuron that is made up of extending, myelinated nerve fibers, or axons. It composes the structures at the center of the brain, like the thalamus and the hypothalamus. It is found between the brainstem and the cerebellum. It is the white matter that allows communication to and from grey matter areas, and between grey matter and the other parts of the body. It functions by transmitting the information from the different parts of the body towards the cerebral cortex. It also controls the functions that the body is unaware of, like temperature, blood pressure and the heart rate. Dispensing of hormones and the control of food, as well as the intake of water and the exposition of emotions, are additional functions of the white matter.

Read more: Difference Between Grey and White Matter | Difference Between | Grey vs White Matter http://www.differencebetween.net/science/health/difference-between-grey-and-white-matter/#ixzz2zYm3R4L4
_____________________________

So I would think that in the T sufferer the white matter is malfunctioning.

 

[jchinnis]

I believe once the input is restored the ringing should stop and ive good reason to believe this.I was reading an article in an Irish health magazine about a man who proves this hypotheses.He had lost most of his hearing at birth from sort of virus I think it was.As he grew older his hearing diminished even further and later devoloped T as a result and could hear what sounded like people talking even though he was profoundly deaf.Worried he went to his specialist thinking he had gone crazy but they could provide no answers.Eventually he got a call from a specialist in the U.S who was intrested in helping him.After an examination the doctor came to his conclusion.His diagnosis was that the input from the cochlea was so low that the brain was compensating for the low input of sound by creating phantom sounds and using sounds from the auditory memory as compensation.He was scheduled to receive a cochlear implant after this he reported that his T had reduced by 90percent.He was then given a second implant which is rare considering most people get one.After this it took about 2 months and his symptoms had completely disappeared which is a good proof of concept that once input is restored the T should disappear.I cant find this story yet but il keep looking and post a link.Also there is a similar story on google about a woman from the U.K with similar results she also got two implants check it out.

I agree. But I think this cure may work only for certain types of hearing loss. I doubt that it will work for someone with "normal" hearing, for instance.

There's been research on this and the results are mixed. Sometimes a cochlear implant will eliminate or greatly reduce the tinnitus. Interestingly, because a CI can be turned on and off, the tinnitus disappears only when the CI is turned on. (So much for plasticity...)

 

[jazz]

And it seems clear that tinnitus might thus bear little or no relationship to gross hearing loss (such as shown in an audiogram), yet might have a clear relationship to an incredibly detailed map of hair cell loss--and its history/timing.

I've always found this topic interesting. Here is an an article that explains "hidden hearing loss" and tinnitus.

http://www.tinnitusresearch.org/en/...usResearchArticleSeries_forTRI_4_Schaette.pdf

The article is based in part on this research article, which does include a free full text if anyone is interested: (http://www.jneurosci.org/content/31/38/13452)

http://www.ncbi.nlm.nih.gov/pubmed/21940438

J Neurosci. 2011 Sep 21;31(38):13452-7. doi: 10.1523/JNEUROSCI.2156-11.2011.

Tinnitus with a normal audiogram: physiological evidence for hidden hearing loss and computational model.

Schaette R1, McAlpine D.
Author information

Abstract
Ever since Pliny the Elder coined the term tinnitus, the perception of sound in the absence of an external sound source has remained enigmatic. Traditional theories assume that tinnitus is triggered by cochlear damage, but many tinnitus patients present with a normal audiogram, i.e., with no direct signs of cochlear damage. Here, we report that in human subjects with tinnitus and a normal audiogram, auditory brainstem responses show a significantly reduced amplitude of the wave I potential (generated by primary auditory nerve fibers) but normal amplitudes of the more centrally generated wave V. This provides direct physiological evidence of "hidden hearing loss" that manifests as reduced neural output from the cochlea, and consequent renormalization of neuronal response magnitude within the brainstem. Employing an established computational model, we demonstrate how tinnitus could arise from a homeostatic response of neurons in the central auditory system to reduced auditory nerve input in the absence of elevated hearing thresholds.

 

[bill 112]

My only question is if its not from the cochlea which I dont think mine is even my audiologist thinks its source is near the cerebellum which gives evidence to what Dan posted how do we sort this problem out?

 

[MikeA]

There's been research on this and the results are mixed. Sometimes a cochlear implant will eliminate or greatly reduce the tinnitus. Interestingly, because a CI can be turned on and off, the tinnitus disappears only when the CI is turned on. (So much for plasticity...)

There's a story in the April issue of Tinnitus Today about a gentleman that has experienced a near elimination of extreme tinnitus upon implantation of a CI. When the 'processor' is on, he hears no tinnitus. When he takes the processor off at night, tinnitus returns, but at a much lower level than before the implant.