0:01

So one of the most common studies that you will

0:05

encounter in the head neck is the

0:07

evaluation of CP angle masses.

0:11

And the reason we do CP angle masses is to evaluate

0:14

patients that have these various symptoms,

0:16

which include things such as hearing loss,

0:18

dizziness, vertigo, and tinnitus.

0:21

And part of the goal of this specific area on

0:24

Cerebella Pontine angle masses is to help

0:27

differentiate between entity number one and

0:30

entity number two and entity number three.

0:33

Now, on the surface, they look somewhat similar,

0:37

but in reality, this is a schwanoma,

0:40

this is a meningioma, and this is an epidermid.

0:43

And we'll be talking a lot more about these

0:45

different disease entities. But eventually,

0:47

all these disease entities can present with these

0:50

type of symptoms, which include hearing loss,

0:52

dizziness, vertigo, and tinnitus. But for me,

0:54

it's always been important when you start to

0:57

evaluate patients that have hearing loss,

1:00

is to understand where this

1:01

fits into the big picture.

1:03

Because when we look at patients that

1:05

have hearing loss or dizziness,

1:08

we have to understand how we hear.

1:10

So eventually we hear through sound waves

1:13

being converted into mechanical energy,

1:16

being converted into fluid energy,

1:18

and eventually the fluid energy is then converted

1:22

into electrical energy that gets

1:24

transmitted to the brain.

1:26

So when we're talking about patients with

1:28

Cerebella pontine angle masses,

1:30

we're really looking at the downstream anatomy,

1:34

because it is these nerves that eventually extend

1:37

from the cochlea through the cerebellopontine

1:40

angle and then into the brain.

1:43

When we look at the detailed anatomy of the cochlea,

1:47

the part of the inner ear that converts the fluid

1:50

energy into the electrical energy is this organ

1:54

right here, which is the organ of corti.

1:56

So the organ of corti really what it is.

1:58

It's a hydroelectric plant that converts fluid

2:02

energy into electrical energy, and eventually,

2:05

it's that electrical energy that

2:07

gets transmitted to the brain.

2:09

So when we look at that detailed anatomy

2:12

involving the internal auditory canal,

2:14

we are now specifically going to look

2:16

at the internal auditory canal.

2:18

We're going to look at these four nerves

2:20

that eventually extend into the brain.

2:22

And the way that we see these nerves,

2:25

we will comment on the next section,

2:27

which will be specifically dedicated

2:29

to the imaging technique.