0:01

Although we described chronic inflammatory

0:03

demyelinating polyradiculopathy and the

0:07

hypertrophic motor sensory neuropathy syndromes,

0:11

when we were talking about intradural extramedullary

0:14

lesions, the truth is that these may be

0:17

purely extradural diseases of the nerve roots.

0:21

CIDP is an acquired disorder, usually thought to

0:24

be an autoimmune disorder in which the patients

0:26

present with proximal weakness and paresthesias.

0:29

They may affect the cranial nerves or

0:32

the peripheral nerves, and it is usually

0:34

a bilateral and symmetric process.

0:37

When it's unilateral or asymmetric, it may be

0:39

called MMN, which is multifocal motor neuropathy.

0:44

Here we have examples of a patient who has

0:47

enlargement of the nerve roots, which is

0:49

predominantly in the extradural compartment.

0:52

As you can see, this is going through the

0:54

anterior scalene, middle scalene junction

0:57

involving the brachial plexus, and this is on T2

1:01

weighted scan, T1 weighted scan, and you see that there are

1:04

enlarged neuroforamina as well as the involvement

1:08

of the nerves as they go into the brachial plexus.

1:11

So this is called CIDP, and it is again,

1:15

an autoimmune disorder, which is often treated with

1:19

immunosuppressive medications and definitively with

1:22

plasmapheresis. In the differential diagnosis with

1:26

CIDP are the hereditary motor and sensory neuropathy

1:30

syndromes, such as your Charcot-Marie-Tooth disease and

1:34

Dejerine-Sottas disease, which may be purely extradural.

1:38

Also, in the differential diagnosis, one may

1:41

find some of the mucopolysaccharidoses, which

1:44

also may be associated with enlarged nerve roots,

1:47

as well as dural thickening, most commonly at

1:50

the foramen magnum and C1–C2 junction.

1:54

So these are causes of enlarged

1:57

extradural nerve roots.