0:01

Although we described chronic inflammatory demyelinating

0:04

polyradiculoneuropathy and the hypertrophic motor

0:08

sensory neuropathy syndromes when we were talking

0:12

about intradural extramedullary lesions,

0:15

the truth is that these may be purely extradural

0:18

diseases of the nerve roots.

0:21

CIDP is an acquired disorder usually thought to be an

0:24

autoimmune disorder in which the patients present

0:27

with proximal weakness and paresthesias,

0:29

they may affect the cranial nerves or the peripheral

0:32

nerves, and it is usually a bilateral and symmetric

0:36

process. When it's unilateral or asymmetric, it may be

0:40

called MMN, which is Multifocal Motor Neuropathy.

0:45

Here we have examples of a patient who has enlargement

0:48

of the nerve roots which is predominantly in

0:50

the extradural compartment. As you can see,

0:53

this is going through the anterior scaling,

0:55

middle scaling junction involving the brachial plexus.

1:00

And this is on T2-weighted scan,

1:02

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

1:05

neuroforamina, as well as the involvement of the

1:08

nerves as they go into the brachial plexus.

1:11

So this is called CIDP and it is, again, an autoimmune

1:16

disorder which is often treated with immunosuppressive

1:20

medications and definitively with plasmapheresis.

1:24

In the differential diagnosis with CIDP are the

1:28

hereditary motor and sensory neuropathy

1:30

syndrome, such as your Charcot-Marie-Tooth disease and Dejerine–Sottas disease,

1:36

which may be purely extradural.

1:39

Also in the differential diagnosis, one may find some of the mucopolysaccharidoses

1:44

which also may be associated with enlarged

1:46

nerve roots, as well as dural thickening,

1:49

most commonly at the foramen magnum

1:52

and C1-C2 junction.

1:54

So these are causes of enlarged extradural nerve roots.