Balance Impacted Negatively with Retrosigmoid Approach?

[Pallen]

Hi everyone, I met with an experienced ENT guy yesterday at MI Ear Institute.  He told me something new I hadn't heard before.  He suggested that the retrosigmoid approach might create more problems with balance than the translab approach.  He said that sometimes there were a couple of vestibular (balance) fibres on the cochlear (hearing) nerve, and that since the cochlear nerve is left intact with the retrosig approach, there is a chance those remaining balance nerves could send out false signals.  I had assumed balance would be affected similarly across the different surgical approaches, but he seemed to suggest otherwise.  Anyone have any insights on this?

[ANSydney]

ENTs cannot do retrosigmoid. It's a bit like going to a Ford dealer and asking what brand of car is best.

[Pallen]

Thank you for taking the time to reply.  The doctor I saw is board certified in Neurotology, Otolaryngology and Skull Base Surgery and is part of a large acoustic neuroma center.  I'm sorry if using ENT caused confusion.  If you have insight into my question, I'd appreciate hearing it.  Thanks for your help.

[Greece Lover]

I've not heard that, but the nerves in that part of the head are so delicate and intricate it would make sense that doctors continue to understand their complexity. There are other symptoms that tend to be correlated with specific surgical approaches (for instance, retrosig tends to result in more problems with post-operative headaches for some reason). 

Sounds like this ENT doc is up on the lates research and a good place to go to for advice.

[Pallen]

So I read a bit more on this topic, and thought I would post what I found in case anyone else asks this question.  In the ANA member section under Resources / Patient Info booklets, there is a helpful booklet on improving balance.  The following quote is found on page 16:  "In some cases, persistent imbalance may be due to the poor or abnormal signal coming from residual vestibular nerve fibers on the AN side. This abnormal vestibular nerve signal may interfere with the brain’s interpretation of the signal coming from the other ear’s vestibular nerve."  The solution to this problem, according to the booklet, is either to perform a labyrinthectomy, essentially removing the inner ear and taking out the entire vestibular nerve, or to try to treat it first using Gentamicin injections.

In an another article on vestibular nerve section, done to try to control balance issues for some conditions, the author (Timothy Haine, M.D.) states that "some of the fibers of the vestibular nerve run very close to the cochlear (hearing nerve)," and because of this they may not be completely cut out in the procedure.  https://www.dizziness-and-balance.com/treatment/vn_section.html

If I'm reading these right, it seems that with the retrosig approach, there *could* be some residual vestibular nerve fibres left behind, and in the off chance they send out false signals, they *could* contribute to ongoing balance issues even as the good ear tries to take over.  Not sure if it's worth worrying about, but it seems to fit with what the doctor I originally saw was telling me.

 

[Greece Lover]

That's fascinating, and from the stuff I've learned, it makes sense.  Thanks.

[ANSydney]

Give me one fully functional vestibular nerve and one marginally functional vestibular nerve over just one fully functional vestibular nerve any day.

The way I look at it, the more sensors you have connected to your brain, the better. Look at balance for instance, you've got your two vestibular nerves, what your looking at and tension sensors on your leg muscles all contributing to the wonders of balancing.

I would never use Gentamicin since it damages the vestibular nerve https://www.dizziness-and-balance.com/disorders/bilat/gentamicin%20toxicity.htm . I want to enhance rather that reduce any function I have.

Rather that remove vestibular nerve function to give your brain a constant signal, why not do things that improve your balance such as yoga or bike riding. Find the combination of what you like doing and balance improvement.

This is just my opinion and we're all entitled to our opinion.

[Greece Lover]

I think the point that the science makes here is that the evidence shows that one full vestibular nerve and one compromised vestibular nerve, in combination, makes it harder for the brain to retain good balance.  That's why surgeons remove them on one side (also so tumor doesn't return).  Not sure that this is a place that is subject to opinion.

[Kristena]

I had retrosigmoid, and I'll be honest, my balance is about the only thing that improved! It's still not perfect, and I can't compare it to if I would have had translab, but it's definitely better overall; and I'm not experiencing the sudden loss of balance whenever I would have a burst of tinnitus.

[jami]

HI

I had retrosigmoid, and it turns out that my tumor was growing on the vestibular nerve, so it had to go (along with the cochlear as it was hanging on there as well). Over years prior, I thought my balance issues were due to growing old. I even recall a yoga class a few months before diagnosis where the instructor was telling everyone that good balance was all in your head. Little did she know...

Post surgery, my balance is no worse than it was before and is more consistent now.  It is different for everyone, however.

Jami