0:00

So again, I'm gonna, I'm gonna take the,

0:02

the road most easily traveled,

0:04

which in entrapment neuropathy is the

0:06

axial almost every time.

0:09

Um, even in the thoracic outlet, I, I rely on the axial,

0:13

but there the lung axis projections are,

0:15

are a bit more critical.

0:17

And as you mentioned in your, your talk, um,

0:22

you know, you should only really have one OCONUS muscle

0:25

and, uh, here're, uh, they're like skis.

0:28

They travel in pairs.

0:29

Uh, we've got two oconus muscles

0:31

and typically the, the ulnar nerve is gonna be about six.

0:36

Some people have reported it as much

0:38

as eight millimeters in size.

0:40

It re, it travels with a small, recurrent ulnar artery

0:43

and it's very hard to use size alone, uh,

0:47

to make the diagnosis, uh, of an entrapment neuropathy.

0:50

Um, you showed quite a few cases of cystic degeneration

0:54

and cystic change, axon noesis, uh, of nerves.

0:58

But I also see it the other way too.

1:00

I see paradoxical hypo intensity, paradoxical fibrosis,

1:05

and nowhere is that more apparent than say in Morton's

1:08

neuroma, where you have a friction induced

1:11

neuropathy in the inter metatarsal space.

1:13

And almost all the time,

1:14

that is predominantly a fibrous reaction.

1:17

So there's a fair amount of variability

1:19

in terms of the signal.

1:20

But one, one thing I've found helpful, Megan, is, is

1:23

that on a T two with a paucity of fat suppression,

1:27

just a standard T two, I don't wanna see the nerves bright.

1:30

I want to see them intermediate

1:32

and signal intensity, uh, rather gray.

1:35

So the fact that this is bright

1:36

and a little puffy looking, uh, along

1:39

with the accessory co uh, conus,

1:41

I think makes the diagnosis for you.

1:43

And I, I think you showed an example of a claw hand on,

1:46

on one of your slides as opposed to median nerve

1:49

where they get this sort of benediction hand

1:51

where the other, the other three fingers are bent.

1:54

And, um, this is a proven case of, uh,

1:58

entrapment neuropathy in the cubital tunnel.

2:00

Are there any comments on this one?

2:02

Yeah, you bring up a great point about the,

2:04

the perineural fibrosis

2:06

and kind of that rind of,

2:07

of hypo intense tissue around a nerve.

2:10

Um, yeah, we see that again, a lot

2:12

of postoperative cases can kind of cause

2:15

a secondary compression

2:16

and almost just like a constriction of the nerve itself.

2:19

So yeah, thank you for, for bringing that up.

2:22

Um, the other thing I would point out about this case is

2:24

just this is an error.

2:25

You can get, again, some, some increased signal,

2:29

somewhat artifactually, so in that cubital tunnel.

2:32

So, um, you do have to have

2:33

that corresponding clinical history and,

2:35

and nice to have that, that correlation in this case.

2:39

And, you know, when you're up higher like that,

2:40

you can see the ulnar nerve

2:41

and you, you can get compression up here in the brachial

2:44

tunnel, you know,

2:45

and then, then right behind the, the, the,

2:48

the epicondyle here, uh, it's referred to

2:51

as sulca IL narrow syndrome.

2:52

Then you get into what we call the bony portion

2:54

of the tunnel, which which is housed

2:57

by the posterior components of the collateral.

3:00

And then as you go more distally, again in what I call,

3:03

I refer to this as the soft part of the tunnel,

3:05

where you have the two heads of the flexor carpi narrows

3:08

and there is the ulnar nerve looking a little bit better

3:11

behaved with some small vessels traveling with it.

3:15

I'd like to make a comment

3:16

and ask e both of you, if you've seen it, that

3:19

a large low-lying medial heads of the triceps, which, uh,

3:24

can occur here and involve the, uh, the nerve

3:28

and, uh, sometimes in fact you'll get subluxation

3:31

of the nerve along, along with the, the muscle

3:35

and you get a snapping sensation.

3:37

And I don't know if you've seen cases like that or not.

3:41

I have not seen one of those in the wild.

3:43

I have read about them mostly with my dynamic kind

3:45

of ultrasound evaluation.

3:47

Um, but yes, I, it's something I I'll keep an eye out

3:50

for. I gotta find a case.

3:52

Yeah, send it to me. If you find,

3:55

I have seen one on a reading panel and I,

3:57

and I did not know what it, I didn't get it right.

3:59

So, um, you know, that's one that, uh, sticks with me.

4:02

I've only seen one though live.

4:05

Shall we move on to the next case?