92. When Both Sides Go Dark: Understanding Bilateral Vestibular Hypofunction

In this episode of Grounded: The Vestibular Podcast, we dive deep into bilateral vestibular hypofunction (BVH)—a rare but life-altering condition where both inner ear balance systems are impaired. We’ll break down: What BVH is and how it affects balance, vision, and movement Common causes, symptoms, and the unique ways it differs from unilateral vestibular loss How BVH is diagnosed through clinical tests and patient history Evidence-based treatments, including vestibular rehabilitation therapy and sensory substitution The concept of vestibular dependence and how patients can learn to rely more on vision and proprioception for stability Whether you're newly diagnosed, supporting someone with BVH, or a clinician looking to understand more—this episode is packed with insights, tools, and hope. Tune in and get grounded with us. Links/Resources Mentioned: Vestibular Group Fit (code GROUNDED at checkout!)  More Links/Resources: ⁠The 4 Steps to Managing Vestibular Migraine ⁠The PPPD Management Masterclass⁠ ⁠What your Partner Should Know About Living with Dizziness⁠ ⁠The FREE Mini VGFit Workout⁠ ⁠The FREE POTS - safe Workouts⁠ ⁠Vestibular Group Fit (code GROUNDED at checkout for 15% off your first subscription cycle!) ⁠ Connect with Dr. Madison: ⁠@⁠⁠TheVertigoDoctor ⁠ ⁠@TheOakMethod⁠ ⁠@VestibularGroupFit⁠ Connect with Dr. Jenna @dizzy.rehab.therapist  Work with Dr. Madison 1:1, Vestibular Rehabilitation Therapy Vestibular Group Fit Small Group Coaching (offered throughout the year, sign up for our email list to learn when!) Why The Oak Method? Learn about it here! Love what you heard? Reviews really help us out! Please consider leaving one for us.  This podcast is for informational purposes only and may not be the best fit for you and your personal situation. It shall not be construed as medical advice. The information and education provided here is not intended or implied to supplement or replace professional medical treatment, advice, and/or diagnosis. Always check with your own physician or medical professional before trying or implementing any information read here.

Episode Transcript

(00:04):
Hey, friend. Welcome to Grounded, the vestibular podcast.
I'm doctor Madison Oak, AKA the vertigo doctor.
I am the vestibular physical therapist who is
here to help you with all things dizziness,
imbalance, and vertigo.
In this podcast, we explore the fascinating world
of vestibular disorders. Come with me as we
dive into the journey to discover the mysteries
of dizziness, the brain, inner ear, and the

(00:26):
balance mechanisms that keep us grounded.
Whether you've been managing your dizziness for one
day or for twenty five years, we are
going to get real about what it takes
to manage dizziness, handle the anxiety cycle, and
thrive, not just survive with your vestibular disorder.
First, I want to remind you that this
is never medical advice. Remember this podcast is
for informational purposes only and may or may

(00:46):
not be the best fit for you and
your personal situation.
It shall not be construed as medical advice.
The information and education provided here is not
intended or implied to supplement or replace professional
medical treatment, advice, and or diagnosis. Always check
with your own physician, medical professionals, and health
care team before trying or implementing any information

(01:07):
found here. Meet me in your coziest chair
while we navigate the highs and lows and
the twists and turns of the vestibular universe.
Welcome to Grounded.
Let's dive in.
Hello, and welcome to another episode of Grounded.
My name is doctor Madison Oak, and this

(01:27):
week's win
of the week is by Christine. Christine says,
my elementary school aged kids had a school
dance last night, and there was two hours
of blasting music and strobing lights in the
gym. I did a lot of supportive things
leading up to it. I wore my earplugs
and sunglasses since I didn't I don't have
blue light glasses yet. She knows already that

(01:48):
she's not supposed to wear sunglasses inside, which
is a one in itself. And regularly closed
my eyes and did quick meditations.
That coupled with some ginger gum and a
couple of tools from the dizzy box, which
is by RuWell,
discount code vertigo doc if you want to
get in on that,
helped a lot with overstimulation.
I love this. Nowhere in here was she,
like, I had a panic moment and needed

(02:10):
to leave and had so much dizziness and
whatever. And even if that is the case,
even if you're listening to this right now,
you're like, that did happen.
You know that's the case, you did the
things that you needed to to cope
with a lot of stimulation. Anyone knows an
elementary
aged kid at a dance with strobe lights
and mute plastic music knows that that is

(02:30):
hard to tolerate
for pretty much
literally everyone.
So congratulations to you, Christine, for making it
through this
and using all of your tools and
honestly
just doing well with it overall because this
is a huge step in the right direction,
and I can't wait to see what you
do next. Congrats.

(02:51):
Alright. We are now talking about bilateral
vestibular
hypofunction.
This is
a frequently asked question, but but I think
it's a frequently asked question because I think
a lot of people are misdiagnosed with it.
Bilateral vestibular hypofunction or bilateral vestibular dysfunction, BVH
or BVD.
Not to be confused by binocular vision dysfunction,

(03:13):
BVD, it's very confusing. Bilateral vestibular hypofunction
is when both of your vestibular
systems, both of your inner ears, are not
working properly. So the system in your inner
ear, your vestibular system,
both of them should be firing at the
same time saying, I am looking forward and
if you're watching on YouTube, you can watch
me do this. But basically they say, I'm

(03:35):
looking forward. I'm looking forward all the time.
When you look to the right, the right
side fires more. The left side fires less.
And it says, okay. I'm looking to the
right and then to the left and vice
versa all day long. Now
the problem is
when this is not happening, when you have
a unilateral vestibular hypofunction,
let's say for argument's sake you have 0%
function on your right side, your left side

(03:56):
is pretty cool. It can compensate for
that. But if for some reason you have
0% function, which is really what we're talking
about here, on both sides,
it is going to pose
a pretty significant vestibular disorder. Now that being
said,
I, again, think a lot of people are
misdiagnosed or overdiagnosed with this. Not because it

(04:17):
doesn't exist. It absolutely, positively exists,
but because the VNG or video nystagmography
exam
is not a perfect test. And so the
calorics portion
of the VNG test where they put the
air or the water in your ear, they
see how long your eyes move around for
that's supposed to happen. If it is done

(04:37):
incorrectly,
it can come back with a BVH diagnosis.
So if you have a caloric test that
says you have 0% function on either side,
I highly recommend getting it redone
at least one more time. So
this chronic lack of signal is a problem,
but
a lot of people don't end up having
it. And I I send people back for

(04:59):
VNGs enough and they come back that say,
actually, it showed function in both sides that
it is there.
Bilateral vestibular hypofunction
is about lack of signal.
It is not about spinning. You could technically
still have spinning if you had vestibular migraine,
which makes it a little bit confusing.

(05:19):
But if you have no signal through either
vestibular nerve from your vestibular system, it is
your vestibulocochlear
nerve, but from the vestibular portion.
If you have no signal from either side,
you cannot spin.
So your symptom,
usually the prevalent symptom here, is ultimately going

(05:39):
to be imbalance. If you have
a history of taking gentamicin
or certain chemotherapy drugs, this can happen. They're
called ototoxic
medications,
some autoimmune
inner ear diseases, some genetic conditions. If you
had bilateral vestibular neuritis, it caused 0% function
on both sides. That is very rare, like

(06:01):
very rare.
But I guess it's possible because most neuritis
is you still have some function on one
side.
Sometimes it's idiopathic,
meaning we do not know why it happens.
The main symptom
of bilateral vestibular hypofunction
is going to be unsteadiness when walking,
especially in the dark or uneven ground because

(06:23):
now you only have proprioception
and vision to depend on. You are going
to be visually dependent and that is ultimately
going to be a coping strategy for you
because
if you were not visually dependent and you
were trying to depend on something that is
not there, it's not gonna work. It would
be like if someone who is completely blind

(06:43):
attempted to rely on their eyes for balance,
and you can no longer
rely on your vestibular system for balance.
The next is oscillopsia.
So that is
gaze instability. So when your vision bounces or
blurs with head motion,
this is pretty common honestly. But when it's
with BVH, it does not compensate because in

(07:05):
unilateral hypofunction,
you're using your opposite ear to attempt to
compensate.
In bilateral,
you cannot compensate using your other side.
Therefore,
some level of oscillopsia
is relatively permanent for people. It will be
worsened in low light and visually complex environments,

(07:26):
again, because you are going to have
visual dependence and it's not something we're trying
to get rid of. A lot of times,
like, your visual dependence, we're gonna try to
wean you off of being visually dependent, but
here we need to use it as a
coping and compensation strategy.
And again,
it does not cause a spinning sensation if
you have 0% function on both sides. It

(07:49):
does not. Most people report feeling like they're
uneasy or swaying on a boat, things like
that, walking on marshmallows,
which are not to be confused with vestibular
migraine. If you have these symptoms, it does
not mean that you have BVH. You need
to get a calorics exam to confirm that
because, again, all vestibular
symptoms

(08:09):
go in every single vestibular disorder bucket. Like,
spinning goes in almost every single one. Like,
you can have spinning with BPPV, vestibular migraine,
vestibular neuritis, vestibular labyrinthitis, meniere's disease. These symptoms
are not specific to diagnoses,
so I just want you to know that.
You can get tested again with a rotary

(08:30):
chair test. You could actually get tested with
a
VHIT or Videohead impulse test, VEMP and caloric
testing,
VNG, and then a DVA, which is a
bedside exam, a dynamic visual acuity test. Is
there
improvement to be had to improve your function
and quality of life? Yes, absolutely.

(08:52):
It is really, really important
for people with bilateral vestibular hypofunction
to strength train. I know I say this
all the time for every single vestibular disorder,
and this applies to every single vestibular disorder.
It really does. But especially if you have
bilateral
vestibular hypofunction, and this is because,
basically, your

(09:12):
proprioception
is going to need to be really, really,
really excellent. And one of the best ways
to strengthen your proprioception are going to be
balance exercises
and then strength training. It also builds confidence
and does other things you need to strength
train. There's no which way about it, and
we have safe ways for you to do
so. Of course, obviously,
in vestibular group fit, there's a sale next

(09:34):
week in the twenty eighth and the twenty
ninth. I will get you the code soon
as well. Other things like wearing flatter shoes,
bringing a walking stick,
making sure you have a partner with you
if you are going to go on, like,
a hike with really uneven ground. Things like
that,
are all really going to be helpful.
You can compensate usually a little bit with
gaze stability. So VOR times one, VOR times

(09:56):
two exercises.
So when I see a patient with BVH,
I typically try to get them the best
that I can, but they're not gonna get
all the way up to that, like, 240
beats per minute.
So we're probably not gonna get all the
way there.
We're gonna get
part of the way there. So your oscillopsia
is not as significant. But compensation strategies, again,

(10:18):
are still going to be a big piece
of this. And then habituation to reduce sensory
overwhelm. Although
we do need you to be slightly more
dependent on your vision than in other vestibular
disorders,
we still don't want it to feel like
when you walk into a room full of
people, like there's so much overwhelm and panic
and,
just feeling not like yourself and things like

(10:40):
that. So there is going to be some
level of
figuring that out. And so habituation,
nervous system regulation,
sensory practice, things like that are all going
to help. Again,
assistive devices are also going to be really
important. So
as much as you can, put a nightlight
or motion sensor to prevent falls in the

(11:00):
dark, don't have a super squishy rug in
your room, avoid walking on super uneven surfaces,
be cautious in crowds and busy visual environments,
take breaks if you're feeling overloaded,
build gentle movement and strength training, please, please,
please, please, please,
into your day to keep your system adapting
and kind of moving forward.

(11:22):
This is not the most common vestibular disorder,
but it is one that I get really
commonly asked about. So if you have 0%
function on either side, this is what most
applies to you. It is very real. It
is very frustrating. Getting the correct support therapy
mindset work
is all
important because improvement is definitely possible.

(11:43):
You are not alone.
There are is a growing community of vestibular
warriors,
who do get it. We get it in
vestibular group fit if you need us. Other
resources
like a local PT, there are probably some
support groups, and then of course the Vestibular
Disorders Association
can all be helpful as well.
Thank you so much for tuning in. All

(12:04):
about bilateral vestibular hypofunction,
not binocular vision dysfunction.
If you found this helpful, please subscribe,
leave a five star review, and share it
with someone who might need it. Until next
time. I love you. Bye.
Listening. If you
liked this episode, head to the show notes
and take the free vestibular migraine and persistent

(12:24):
postural perceptual dizziness master classes. If you're interested
in undoing your chronic dizziness and feeling better
faster, join us in vestibular group fit using
code grounded, all caps, for 15% off.
Find me on Instagram at the vertigo doctor
and doctor jenna at dizzy dot rehab dot
therapist.
Your success story begins today. Dizziness doesn't have
to be forever, so let's get you the

(12:45):
right tools to thrive.
Remember, rate review and subscribe to this channel
wherever you are listening so we can keep
getting great guests and reaching new vestibular warriors.
Love you, and see you next time on
Grounded.