CIDP

Question 1

Potential CIDP patient. If a patient has an IgM monoclonal gammopathy, what should checked on lab?

Answer 1

Myelin-associated glycoprotein (MAG) antibodies

Question 2

Potential CIDP patient. If a patient has IgG or IgA monoclonal gammopathies, what should be checked and why?

Answer 2

• Skeletal survey (osteosclerotic myeloma or plasmacytoma)
• Vascular endothelial growth factor (VEGF) (to exclude POEMS)
• Polyneuropathy, Organomegaly, Endocrinopathy, Monoclonal plasma cell disorder and Skin changes

Question 3

If CSF leukocyte count is > 50 cells/mm3 (when looking for CIDP) what could this suggest?

Answer 3

• Lymphoma
• Leptomeningeal carcinomatosis
• Neurosarcoidosis
• HIV

Question 4

What does a nerve conduction study commonly show in both acute and chronic acquired demyelinating neuropathies?

Answer 4

• Prominent involvement of the UE sensory nerves
• Sural sparing

Question 5

In pure demyelinating neuropathies, what could be the only finding on EMG?

Answer 5

Reduced recruitment of normal morphology motor unit potentials

Question 6

What can a MRI of the PNS show in a patient with CIDP?

Answer 6

Enlarged enhancing nerve roots, plexus and peripheral nerves

Question 7

What is the initial treatment for CIDP?

Answer 7

IVIg 2g/kg divided over 2-5 days with maintenance of 1g/kg q 3 weeks

Question 8

How long should a CIDP patient get IVIg to assess for a response before switching to another therapy? When will you see a maximal response?

Answer 8

• 6 weeks
• Maximum response at 12 weeks

Question 9

What are the options for steroid induction therapy in CIDP?

Answer 9

• Prednisone 1 g/kg/d
• Dexamethazone40 mg/d x 4 days q 4 weeks
• IV methylprednisolone 0.5 g one day each week or for 4 consecutive days monthly

Question 10

What 2 meds are commonly used with steroids to help with weaning the steroid dose?

Answer 10

Azathioprine or Cell Cept

Question 11

What are the CIDP Variants?

Answer 11

• Sensory (sensory CIDP or CISP)
• Motor predominance (motor CIDP or MMN)
• Asymmetry (MADSAM)
• Distal predominance (DADS neuropathy)

Question 12

What is the typical clinical presentation of sensory CIDP?

Answer 12

• Early ataxia
• Early UE involvement
• Diffuse hyporeflexia
• Cranial nerve involvement
• Onset before age 55

Question 13

What is the typical clinical presentation of Chronic Immune Sensory Polyradiculopathy (CISP)?

Answer 13

• Prominent sensory symptoms and sensory Ataxia
• Normal nerve conduction studies
• Delayed SSEP
• Elevated CSF protein
• Enhancing nerve roots on MRI L spine

Question 14

What are the treatments for chronic immune sensory polyradiculopathy (CISP)?

Answer 14

• Corticosteroids
• IVIg

Question 15

What will Pure motor CIDP show on nerve conduction?

Answer 15

It will show motor demyelination but can have sensory changes as well (rarely) even though the symptoms are all motor

Question 16

What can happen if a Pure motor CIDP patient is treated with steroids?

Answer 16

He can get worse (just like MMN)

Question 17

What is the pathophysiology of MMN?

Answer 17

Partial motor conduction block due to anti-GM1 antibody mediated conduction failure at the node of Ranvier

Question 18

Is MMN a demyelinating syndrome?

Answer 18

No. It is a nodopathy

Question 19

What is the typical clinical presentation for MMN?

Answer 19

• Asymmetric distal UE weakness with cramps and fasciculations in affected peripheral nerve territories
• Cold paresis –> Increased weakness during cold (can also be seen with other motor neuropathies, like monomelic amyotrophy)

Question 20

Will there be significant atrophy with weakness with MMN?

Answer 20

No, unless there is significant secondary axonal degeneration

Question 21

What will nerve conduction show in patients with MMN?

Answer 21

Partial motor conduction block at noncompressible sites

Question 22

What percent of patients with MMN will have positive GM1 antibodies?

Answer 22

40 to 60%

Question 23

What will MRI of the brachial plexus show in patients with MMN?

Answer 23

T2 hyperintensity and contrast enhancement