Treatment Prospects: Vagus Nerve Stimulation

Here's a quick and nice response from Dr. Kilgard on the development of an enhanced VNS stimulator:

Our current experimental therapy reduces tinnitus severity by about half of people who receive the therapy. We are hoping to do better and are actively working to optimize the therapy.

Unfortunately, it will take at least a year before the new and improved VNS therapy could be approved.

You can track our progress by signing up for our newsletter at https://www.utdallas.edu/txbdc/newsletter/

Best wishes,

Dr. Kilgard

 

My opinion is that surgically implanting a VNS device probably doesn't offer much more than the non-invasive devices routing through other avenues like Lenire going through the tongue. The secret sauce has to do with the simulation parameters, which, as of yet, have shown to be unproven.

 

Is this invasive? Sorry, I haven't kept up with the vagus stimulation treatment research.

 

Yes, it's invasive, but generally considered more safe than other devices like DBS.

 

You may be right @Glenn. It's a questionable matter. Question remains if directly stimulating the vagus nerve via a surgically placed stimulator is more effective than indirectly via the tongue (Lenire). Direct stimulation may be more effective, because it activates the nucleus basalis, which in turn could have a more profound effect on neuroplasticty.

Here's an explanation by Ross about the difference & rationale approach between Lenire and University of Texas/MicroTransponder:

Ross: Right, so there’s also a group in the University of Texas as well. Some of the treatments would target different nerves. Some groups concentrate on the Vagus nerve, so they pair Auditory Stimulation with Vagal Nerve Stimulation because there were a number of papers that showed that a sensory based nerve can activate nucleus basalis which is a key attentional centre and, as I said before, driving attention kind of hardwires the effects into the brain faster so they took that approach. Unfortunately, the only way to access the Vagus nerve is through surgery so it’s a highly invasive procedure. Other devices also target, let’s say the trigeminal nerve, non-invasively but they may do it by stimulating the face or the neck. Now, for us we chose the tongue because, essentially, it’s the most enervated part of the body outside of the fingertip. So, in terms of ‘bang for your buck’ if you’re going to stimulate any nerve that’s the place to do it. Also, the tongue doesn’t have the epidermal layer so it means that you can stimulate it with much, much lower levels of electricity which is much safer.

Link: https://www.tinnitustalk.com/podcas...innitus-talk-podcast-ep07-neuromod-lenire.pdf

 

I really think this research is a dead end and what they're really seeing is the placebo effect. You can actually stimulate the vagus nerve by sticking a q-tip in your ear [1]. When I was younger, I always coughed when I cleaned out my ears and had no idea why until a doctor told me (I don't have a chronic cough though, I only cough when the nerve is stimulated).

If I use a vibrating device on my ear it feels weird, and kind of takes my mind off the tinnitus. It's similar to how HeadOn worked. HeadOn didn't do anything for a headache, but the nice tingly sensation it gave your forehead took your mind off it and made you think it was working in other ways.

The placebo effect is going to make it really hard to find a good treatment for tinnitus. Unless these trials are similar to FX-322 where they only treat one ear, and they test a few weeks after treatment, I would think much of them.

[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4222929/