The Neuroscience of Tinnitus

Tinnitus-related neural activity: Theories of generation, propagation, and centralization



Abstract

The neuroscience of tinnitus represents an ideal model to explore central issues in brain functioning such as the formation of auditory percepts, in addition to opening up new treatment avenues for the condition in the long-term. The present review discusses the origin and nature of tinnitus-related neural activity. First, we review evidence for the hypothesis that tinnitus is caused by the central nervous system changes induced by sensory deprivation, even when hearing loss is not visible in the audiogram. Second, we suggest that changes in neural activity in individual central structures may not be sufficient to underlie the tinnitus percept. Instead, we propose that tinnitus may arise from functional alterations at multiple levels which promote abnormal propagation of neural activity throughout the network involved in auditory perception. In this context, functional coupling within and between central auditory structures may be especially important to consider. Investigating how sensory deprivation affects functional coupling between areas, which might be reflected in changes in temporal coherence of intrinsic ongoing activity patterns, may give critical insights into the mechanisms of tinnitus.

Full Article Link

 

I am not a scientist but I believe it is trying to say that tinnitus is a change in our nervous systems caused by sensory deprivation, meaning that if there is a a loss or some loss of one of our senses and in the case of tinnitus hearing, then it causes neural changes within our brain. What is meant by the line "even when hearing loss is not visible in the audiogram" is that even if your audiogram shows "normal" hearing there is still more than likely some type of hearing loss even if minor and this loss causes the changes in our brain. Audiograms only show a certain range of human hearing which is considered the normal range. But human hearing range can be much greater than the standard audiogram. You can have hearing loss at much higher frequencies, but those will not show on a standard audiogram, and still have tinnitus. These are the people referred to as having tinnitus with "no hearing loss" but in fact there probably is some. I fall into that category. I have no loss up to about 13K. That was only discovered with a high frequency audiogram.

Furthermore, these neural "brain" changes happen at multiple levels and regulating these feedback mechanism changes in the central auditory system "may give critical insights into the mechanisms of Tinnitus". This in turn will lead to more effective treatment options. Studies now are already showing that because our brains are plastic, it may be possible that auditory training/stimulation using rTMS (magnetic therapy) and other therapies, can alter the response properties of neurons in auditory pathways and reduce or eliminate tinnitus.

 

So... in conclusion:

For the record, I did take time to read the whole thing. They discuss about different target brain areas for stimulation, different stimulation techniques, but they mainly stay focused on DBS (deep brain stimulation). For all they want to do they can't target specific areas without stimulating other areas, or not without invading your skull (invasive vs. noninvasive), and even then they may not be able to reach into the target areas. They talk about possibly reaching into MGB (medial geniculate body), which is of course more superficial. An obvious obstacle is the complicated brain anatomy.

I call this exploratory surgery and exploratory stimulation. They don't really know what they're doing, they are just poking around and hoping for the best. In my opinion this should be only used in the worst cases of tinnitus, if at all.

I wonder what makes them real, or more real than others? What is this hard evidence? They are using references to research papers by imaginary doctors?

I believe that neuroscience will be instrumental in helping us understand tinnitus. There is no doubt about it in my mind. But we are still in early years of research.

 

Capish! Open brain stimulation it is then!

Of course, some people may need a brain surgery anyway, and if they happen to have tinnitus that goes away after the surgery, that's something we might be able to learn something from.

 

Are you saying we should only trust those who are MD and PhD?