Hello, I'm going to talk about problems with balance and dizziness and specifically those
related to problems with the ear.
First of all using this Adam Rouilly model, I'll talk you through essentially how the
ear works. Firstly the ear is related to hearing. Hearing works by this part of the air known
as the pinna picking up sound waves. It effectively deflects the sound waves down the ear canal
which hits the ear drum. This causes vibration of the eardrum which in turn vibrates three
small bones within the middle ear, the space behind the ear drum, and that stimulates the
inner ear which is this part, buried deep within the bone.
I’ll take this out and look at it in more detail. The inner ear has essentially two
halves. This half which we called the cochlear, this is the organ of hearing. So when sound
waves hit this which is the smallest bone of hearing it will then cause a wave of fluid
to pass within this part of the inner ear which we call the cochlear. Within this part
of the inner ear are very small hair cells, and that wave of fluid will cause bending
of those hair cells which is then perceived as sound by the brain. Those electrical sig-nals
that the cochlear forms are sent to the brain through this nerve which we call the cochlear
nerve.
The inner ear also has this half which is the organ of balance, the organ that is relat-ed
to head movements and body movements. Basically with regard to balance our inner ear really
is just a movement detector. When we walk down the street and look in shop windows and
are able to walk across uneven ground there are three main inputs into the brain that
allows us to stay balanced. The primary inputs which ac-count for about 80 to 85 percent
of our sense of balance comes from vision and a sense we call proprioception which is
joint position sense. So essentially when we're walking across an uneven beach, a rocky
beach for example and our ankles are constantly moving over the uneven ground those signals
are picked up by the brain which is then able to keep us upright and controlled. When we
move our head against gravity, so either in the forwards backwards direction up and down
or rota-tion, that is picked up by the inner ear.
The inner ear has five small organs within it. There are two organs that are set in this
area here, and on the surface of these there's a small layer of chalk crystals or calcium
carbonate crystals and they provide weight against gravity. Beneath these are small hair
cells, so when the crystals shift in one direction they cause bending of these hair cells which
again will stimulate the nerve. The inner ear also contains these three areas which
are known as semi circular canals and they contain fluid. These are placed at perfect
right angles to each other as we can see in this model and therefore cover all planes
of movement, the two organs here which detect movement against gravity with those crystals
of calcium carbonate, they detect movement in a linear or straight plain. For example
moving backwards and forwards or side to side in a horizontal plane, or up and down in a
vertical plane such as going up or down in a lift or falling. Rotational movement of
the head is picked up by these three semi circular canals. They tend to be in this orientation,
therefore this canal or the superior canal tends to detect movement going from side to
side, shoulder to shoulder, this canal or the horizontal canal detects as the name suggests
horizontal movement to the head, for example saying no. And this canal, known as the poste-rior
canal detects movement going backwards and forwards so nodding and saying yes.It’s
actually orientated slightly like this, so it is just to one side going up and down is
the maximal stimulation.
If we have problems with the inner ear, that can give us dizziness. Generally speak-ing
dizziness caused by problems of the inner air is actually described as something called
vertigo. What we mean by vertigo is an hallucination of movement, so essen-tially feeling like
we're moving when we know that we are still.
There are probably about 50 or 60 potential diagnoses that might affect us, giving us
balance problems and dizziness. Some of these might be related to the heart, relat-ed to
how the brain perceives what's going on and related to blood flow and blood pressure.
There are a number of conditions however of problems with the inner ear itself they can
give us a sensation of vertigo or dizziness. We'll talk through a few of these common reasons.
The first condition is something which we call benign paroxysmal positional vertigo
or BPPV for short. This is very common and what happens in this condition is some of
those small calcium carbonate or chalk crystals in this part of the inner ear become loose
or detached. They can then float into the tubes in this part of the ear, the most common
of which is this tube, the posterior canal. What happens then is when we move our head,
even though the canal is picking up that movement and stimulating the nerve those crystals floating
within that the fluid within this canal can sometimes stimulate the inner ear to make
it feel like we're moving even though we are not. Classically it predominately affects
this canal which is the posterior canal, and if you recall that is the canal that is stimulated
in this position. Therefore BPPV tends to affect patients primarily when they are lying
down and turning over to the side of the affected ear, when they are looking up or when they're
looking down.
BPPV gives patients vertigo or a spinning sensation which tends to last just for a few
seconds at a time when stimulated in that particular positions. If you're having this
problem it is best to seek assistance from your GP who then will be able to refer you
on to an ear nose and throat specialist for treatment. Treatment of this condition is
relatively straightforward with something we call a particle repositioning manoeuvre
that involves rotating the patient's head in a particular direction to allow those crys-tals
to slowly float around this canal and drop back out again into a part of the inner ear
where they should be. It can cure 80 to 85 percent of patients on one manoeu-vre that
needs to be appropriately diagnosed in the first instance.
Another condition that might give us vertigo that affects the inner ear is a condition
called vestibular neuronitis. In this condition we can have a virus that causes in-flammation
of this part of the inner ear which is the vestibular nerve or the nerve of balance.
That will often make us feel very very dizzy and vertiginous and that vertigo may last
for a few days to even a couple of weeks. Patients will often feel that there is a constant
spinning and at all movements will make them feel worse and they will often be vomiting
and very nauseous. Basically because this is a virus a little bit like a cold we just
have to wait for it to settle, but your doctor may be able to give you some medication which
will dampen down the intensity of the symptoms for the peri-od of the condition until it
is fully resolved.
Another condition that can affect some patients albeit rare, is a condition known as Meniere’s
disease. In this condition we can get inflammation or too much fluid buildup within the whole
of the inner ear. In that respect it affects not just balance and dizziness but it can
also affect our hearing. Classically with a condition such as Meniere’s disease, patients
will have attacks that last for minutes to hours and what happens during an attack is
their hearing will drop, they will describe a tinnitus or a buzzing sound in their ear
and they will get acute vertigo, a spinning sensation that lasts throughout that length
of the spell. There are various different treatments for Meniere’s disease but it
has to be diagnosed appropriately, as it is is often misdiag-nosed in a large number of
patients. To that end what patients’ would need would be a series of hearing tests and
an assessment by a specialist EMT surgeon.
A very common condition that actually doesn't really affect the inner ear as such but affects
the brain is a condition known as vestibular migraine. This can often mimic Meniere’s
disease and classically will give patients a vertigo sensation, feeling nau-seous, possibly
vomiting which can last anything for minutes to a few days. Patients may or may not have
headache with this type of migraine as this is one of the many types of migraine that
don't always give patients headaches. Again this condition needs to be appropriately diagnosed
and treated, so if you are having any dizzy spells or vertigo that is going on for a period
of time and not settling, it’s always best to see your own doctor and potentially have
a referral to an ear nose and throat specialist with an interest in dizziness and balance.
I hope that that is helpful in explaining how the ear can give us problems with our
balance. Any concerns always see your doctor. Thank you.