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This is an unusual example of an entity that's

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referred to as multifocal motor neuropathy.

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And what this is, is an autoimmune response of

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the body against your own nerves and the nervous

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system that results in progressive weakness.

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This entity does allow us to discuss

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various types of imaging appearance of

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idiopathic inflammatory neuropathies.

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When we look on the left-hand side here, we see

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these coronal fat-suppressed T2-weighted images.

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What we see is diffuse abnormal

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thickening and abnormal signal involving

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the components of the brachial plexus.

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So notice how we can see abnormal signal

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extending all the way back to the nerve

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root, extending anteriorly along a single

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nerve root that eventually comprises the

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components of the plexus on the right.

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On the left-hand side when we scroll

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through, we also see asymmetrical

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abnormal signal involving that nerve root.

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And as we scroll back and forth, again,

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we can see much too much abnormal signal

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involving other components of that plexus.

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When we look at the sagittal images,

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this is on one side and this is on the

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opposite, what we see is diffuse abnormal

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signal and abnormal enlargement of

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the involved and inflamed nerve roots.

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Similarly, on the opposite side, we can see

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diffuse enlargement and abnormal signal.

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Now, if you compare this appearance

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with the nerve roots located a little

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bit more inferiorly, we can actually

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see the normal appearance of a nerve

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root here with the surrounding CSF.

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So, this emphasizes the fact that this type

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of inflammatory neuropathy causes edema and

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enlargement of the nerve roots, and then when

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we look at the STIR images, this abnormal

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signal involves a full course of the nerve root

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extending peripherally into the brachial plexus.

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And this is what's resulting in this

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patient's slowly progressive upper neuropathy.