CIDP Flashcards
Potential CIDP patient. If a patient has an IgM monoclonal gammopathy, what should checked on lab?
Myelin-associated glycoprotein (MAG) antibodies
Potential CIDP patient. If a patient has IgG or IgA monoclonal gammopathies, what should be checked and why?
- Skeletal survey (osteosclerotic myeloma or plasmacytoma)
- Vascular endothelial growth factor (VEGF) (to exclude POEMS)
- Polyneuropathy, Organomegaly, Endocrinopathy, Monoclonal plasma cell disorder and Skin changes
If CSF leukocyte count is > 50 cells/mm3 (when looking for CIDP) what could this suggest?
- Lymphoma
- Leptomeningeal carcinomatosis
- Neurosarcoidosis
- HIV
What does a nerve conduction study commonly show in both acute and chronic acquired demyelinating neuropathies?
- Prominent involvement of the UE sensory nerves
- Sural sparing
In pure demyelinating neuropathies, what could be the only finding on EMG?
Reduced recruitment of normal morphology motor unit potentials
What can a MRI of the PNS show in a patient with CIDP?
Enlarged enhancing nerve roots, plexus and peripheral nerves
What is the initial treatment for CIDP?
IVIg 2g/kg divided over 2-5 days with maintenance of 1g/kg q 3 weeks
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?
- 6 weeks
- Maximum response at 12 weeks
What are the options for steroid induction therapy in CIDP?
- 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
What 2 meds are commonly used with steroids to help with weaning the steroid dose?
Azathioprine or Cell Cept
What are the CIDP Variants?
- Sensory (sensory CIDP or CISP)
- Motor predominance (motor CIDP or MMN)
- Asymmetry (MADSAM)
- Distal predominance (DADS neuropathy)
What is the typical clinical presentation of sensory CIDP?
- Early ataxia
- Early UE involvement
- Diffuse hyporeflexia
- Cranial nerve involvement
- Onset before age 55
What is the typical clinical presentation of Chronic Immune Sensory Polyradiculopathy (CISP)?
- Prominent sensory symptoms and sensory Ataxia
- Normal nerve conduction studies
- Delayed SSEP
- Elevated CSF protein
- Enhancing nerve roots on MRI L spine
What are the treatments for chronic immune sensory polyradiculopathy (CISP)?
- Corticosteroids
- IVIg
What will Pure motor CIDP show on nerve conduction?
It will show motor demyelination but can have sensory changes as well (rarely) even though the symptoms are all motor
What can happen if a Pure motor CIDP patient is treated with steroids?
He can get worse (just like MMN)
What is the pathophysiology of MMN?
Partial motor conduction block due to anti-GM1 antibody mediated conduction failure at the node of Ranvier
Is MMN a demyelinating syndrome?
No. It is a nodopathy
What is the typical clinical presentation for MMN?
- 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)
Will there be significant atrophy with weakness with MMN?
No, unless there is significant secondary axonal degeneration
What will nerve conduction show in patients with MMN?
Partial motor conduction block at noncompressible sites
What percent of patients with MMN will have positive GM1 antibodies?
40 to 60%
What will MRI of the brachial plexus show in patients with MMN?
T2 hyperintensity and contrast enhancement
