TU Delft & Prof. Dirk De Ridder — Bimodal Stimulation Device for Treating Tinnitus

I made a post about this subject somewhere in this thread. Besides the non-invasive aspect of the TU Delft device, there are additional differences we can expect from it vis à vis VNS devices like MicroTransponder:

 

So it's a habituation device?

 

It's not intended as a habituation device. Dr. De Ridder and Prof. Serdijn have mentioned in multiple articles and interviews that their main aim is to reduce tinnitus severity, not merely the annoyance per se. They hope to retrain the brain's fight-or-flight response to a rest-and-digest response, thereby stopping the generation of phantom sound perception.

This text is from the summary of the NRC article:

Concerning the rationale behind the rest and digest response:

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Concerning Prof. Serdijn's remark:

In my view, we can't judge the effectiveness of a tinnitus treatment like the TU Delft device after just using it once, much like Dr. Shore's Auricle device demonstrates. These treatments rely on neuroplastic changes within the brain, which inherently take time. Dr. Shore's device shows us that for a real, meaningful reduction in tinnitus perception, consistent and long-term stimulation is crucial. It's about retraining our brain's auditory processing, and this process doesn't happen overnight. We need to give these treatments time to work, as the brain adapts and learns to process sounds differently, which could ultimately lead to a significant decrease in the severity of one's tinnitus.

 

So they don't expect their mechanism to actually lower the volume of tinnitus? They hope that something else will take care of that later? I'm curious what data points leads them to believe that this is a reasonable hypothesis.

I know, for example, that in my case (n=1), I do not have any fight-or-flight response like I used to have in the beginning of my tinnitus journey. However, my tinnitus hasn't changed: my brain has not decided to stop the generation of that phantom sound at all.

So as to not limit ourselves to n=1, there are lots of testimonials online (on Tinnitus Talk, but also elsewhere) from people describing habituation as "your tinnitus hasn't changed, you just don't worry about it anymore", and that seems to indicate that even if you get rid of the fight-or-flight response, your brain doesn't decide to stop generating tinnitus.

There may exist testimonials from people who say "I had horrible tinnitus, but I stopped worrying about it and it went away", but I have to say I haven't come across those, neither in the "anecdotal evidence" source that online fora provide, nor on more scientific sources such as PubMed. Certainly not from folks who have measurable hearing damage as result of auditory insults or disease.

 

I have gotten the intimation that Dr. De Ridder doesn't believe firmly in bimodal neuromodulation based on his other talks. I was curious why this device because it mimics Dr. Shore's device. My guess is there is a sense a money train might be coming and they don't want to miss out. I think it most likely means they don't have data to support lowered tinnitus volume.

I am questioning cynically if this could be a way to discredit bimodal neuromodulation in advance of a future treatment yet to be announced.

 

Ah, I didn't mean to pass any judgment concerning Prof. Serdijn's remark.

I just thought it was interesting that Dr. De Ridder felt the need to expand on having used the device, whereas Prof. Serdijn (who actually suffers from tinnitus) understandably answered with "no comment." The bit about a less severe stress response feels like it was added for the sake of the interview/article.

I'm curious to see where this goes. There actually already is a clinic in the Netherlands that offers pulsed radiofrequency of the auriculotemporal nerve. You can read their research on ResearchGate.

 

Funny.

I don't see this helping out with reactivity, hyperacusis, or noxacusis.

 

Valid point. Dr. De Ridder suggests in this article that the mechanism of vagus nerve stimulation (VNS), especially when paired with sound, is expected to influence the perceived volume of tinnitus directly, rather than hoping for an indirect or later effect.

According to Dr. De Ridder, the subjective loudness perception (lateral pathway), distress (medial pathway) & the noise canceling system (descending pathway) are important factors in the manifestation of subjective tinnitus. He support the idea that VNS paired with sound stimulation can reduce the functional connectivity between those pathways in hopes of reducing tinnitus severity, annoyance and awareness. It does this by making certain parts of the brain communicate less with each other via bimodal stimulation. These parts are usually involved in how we perceive the loudness of tinnitus, how distressed it makes us feel and what makes us aware of external/internal stimuli.

Here you can find relevant information from the article concerning the data points that support this hypothesis:

(Source)

Several pathways involved in manifestation tinnitus


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Dr. De Ridder has been conducting extensive research on VNS for tinnitus, with and without sound stimulation, since at least 2014:

De Ridder, D., Vanneste, S., Engineer, N.D., Kilgard, M.P., 2014a. Safety and efficacy of vagus nerve stimulation paired with tones for the treatment of tinnitus: a case series. Neuromodulation 17, 170–179.

Concerning your remark on Dr. De Ridder's view on VNS with/without sound stimulation:

(Source)

See my response to @GregCA about the data concerning lowered tinnitus volume.

 

Perhaps reactivity and hyperacusis is where it works best.

I had a neurologist appointment who did deduce (theory mind) that reactiveness is a neuroplastic change in the brain as a response to auditory changes.

This response continues until, one would assume, neuroplastic changes again to reverse the trigger.

Personally my reactivity appears to be 'echos'. If I come from a call it sounds like a thousand voices as a tinnitus tone, all repeating over each other. A long car drive and I'll hear more hissing. Rain on the roof and the reactivity becomes high pitch. The brain could could be stuck in an auditory feedback loop for a period time.

All tinnitus and hyperacusis theories are speculative, no one knows, but if neuroplasticity changes really have set in causing reactivity, perhaps - just perhaps - bimodal stimulation could reverse that brain change for the better.

 

They have no clue. I see a lot of question marks in Figure 3 on the ends of the diagram.

 

So this is the paper.

Again, as per Dr. De Ridder style, the full article is behind a paywall.

Weaknesses:

• Small group
• No placebo

Strengths:

• Used TFI and Minimum Masking Level (MML)

Again, being just the abstract, there is little information on the methods, little discussion, and no information or data to view on what the changes in TFI and MML were. What were the profiles of the patients? What were the inclusion/exclusion criteria?

Just like the other papers he has been the lead author on, this was barebones. His or Sven Vanneste's paper on Cyclobenzaprine was just the same.

 

Again, as per my style, the full article is attached.

 

You could read the paper to understand the reason for the question mark placed after 'tinnitus loudness' & 'Pavlovian reconditioning'. The word 'may' is pivotal here, since the pairing of tinnitus-matched sound with VNS has not yet been tested in humans. However, there are indications that this approach could aid in reducing tinnitus loudness, based on the outcomes of VNS treatments paired with non-tinnitus sound stimulation.

With the upcoming trial of the TU Delft device, researchers aim to determine whether adjusting parameters could optimize the effects of reducing tinnitus loudness.

Text from paper (concerning fig. 3):

(Source)

 

Thanks @annV.

So a mean decrease of 14 dB for all participants, for those on medication 4.9 dB, and out of the 5 that were on no medication, a permanent mean decrease of 29 dB.

A very small sample size and no placebo. Given the invasive nature, I can understand why.

If that type of result can be achieved with 100 participants, it's a winner.