EAN/PNS 2021 CIDP criteria (and other CIDP stuff)

Question 1

What are the clinical criteria for CIDP?

Answer 1

Symmetric
Proximal and Distal weakness
Sensory loss (typically length dependent)
Globally reduced/absent reflexes
Progression or relapsing > 8 wks

Question 2

How many nerves must be abnormal to satisfy the NCS criteria for CIDP?

Answer 2

2 motor AND 2 sensory nerves = Definite
1 motor + at >1 supportive criteria (CSF, nerve enlargement on u/s or MRI, suggestive nerve biopsy, response to immunotherapy)= Possible

Question 3

What is the motor latency criteria for demyelination?

Answer 3

Motor distal latency prolongation ≥50% above ULN in two nerves (excluding median neuropathy at the wrist from carpal tunnel syndrome)

Question 4

What is the motor CV criteria for demyelination?

Answer 4

Reduction of motor conduction velocity ≥30% below LLN in two nerves

Question 5

What is the motor F wave criteria for demyelination?

Answer 5

Prolongation of F-wave latency ≥20% above ULN in two nerves (≥50% if amplitude of distal negative peak CMAP <80% of LLN)
OR
Absence of F-waves in two nerves (if these nerves have distal negative peak CMAP amplitudes ≥20% of LLN) + ≥1 other demyelinating parameters in ≥1 other nerve

Question 6

What is the motor conduction block criteria for demyelination?

Answer 6

Motor conduction block: ≥30% reduction of the proximal relative to distal negative peak CMAP amplitude, excluding the tibial nerve, and distal negative peak CMAP amplitude ≥20% of LLN in two nerves
OR
In one nerve + ≥ 1 other demyelinating parameter except absence of F-waves in ≥1 other nerve

Question 7

What is the motor temporal dispersion criteria for demyelination?

Answer 7

Abnormal temporal dispersion: >30% duration increase between the proximal and distal negative peak CMAP (at least 100% in the tibial nerve) in ≥2 nerves

Question 8

What are considered the acceptable temperatures for measurements of demyelination?

Answer 8

33 in UE, 30 in LE

Question 9

What are the CIDP variants?

Answer 9

Distal
Multifocal (MADSAM)
Focal (one limb)
Motor
Sensory

Question 10

What lab testing should be done in all CIDP patients to assess for secondary cause?

Answer 10

Paraprotein w/u

Question 11

MADSAM T/F: Upper extremities usually affected earlier than LE and cranial neuropathies not as common as in CIDP patients?

Answer 11

False
True that UE are often affected before LE, but CN more common in MADSAM than CIDP

Question 12

What mimics should be r/o before settling on dx of CIDP?

Answer 12

MMN
Mononeuropathy Multiplex
HNPP

Question 13

What are the various presentations of nerve involvement in Focal CIDP?

Answer 13

One nerve in a limb
Multiple nerves in a limb
Brachial or LS plexopathy

Question 14

What CIDP variant can look identical to MMN?

Answer 14

Motor CIDP. In fact, some think this is a more diffuse form of MMN as some patients can get worse with steroids/PLEX similar to MMN.

Question 15

What are some differences between CIDP and MMN?

Answer 15

CIDP is demyelination whereas MMN is likely a nodopathy
Sensory in CIDP but not MMN
cramps/fasciculations rare in CIDP but common in MMN
GM1 abs often absent in CIDP but present in MMN
CSF protein elevated in CIDP but normal in MMN
Very different response to steroids/PLEX between the two

Question 16

What CIDP variant is most likely to eventually turn into standard CIDP?

Answer 16

Sensory CIDP. 70% will convert to classic CIDP.

Question 17

What is the main difference between sensory CIDP and CISP?

Answer 17

In sensory CIDP , roots and sensory nerves affected (NCS abnormal).
In CISP, only sensory roots affected (NCS normal).
Both respond to IVIG/steroids.

Question 18

What are the antibodies involved in autoimmune nodopathies?

Answer 18

Contactin 1 (CNTN 1) - often more pain/sensory features
Contactin associated protein 1 (Caspr 1) - often more nephropathy
Neurofascin 155 (NF 155) - often more tremor/dysarthria

Question 19

What is pan neurofascin antibody syndrome?

Answer 19

+ NF155 but also 140 and 186.
Severe GBS like presentation with tetraplegia, resp insufficiency, cranial neuropathies, and autonomic dysfunction

Question 20

What does EDX look like in nodopathies?

Answer 20

Mixed axonal/demyelinating

Question 21

What are the treatments for nodopathies?

Answer 21

IVIG can be helpful but will likely require B cell depleting therapy with meds like rituximab.

Question 22

Who generally has higher CSF protein levels: CIDP vs nodopathy?

Answer 22

Nodopathy
These patients often have more respiratory failure, cranial neuropathies, and even nephrotic syndrome.

Question 23

Administration of what time of anti cancer therapy can exacerbate a smoldering underlying paraneoplastic syndrome?

Answer 23

Immune checkpoint inhibitors (primarily with neuro-endocrine tumors)

Question 24

What is the most common neuropathy presentation of CRMP-5 paraneoplastic syndrome?

Answer 24

Asymmetric polyradiculoneuropathy

Question 25

What paraneoplastic antibody can be associated with an autoimmune motor neuronopathy that looks like LMN-MND?

Answer 25

IgLON5 and LUZP4/KLHL11

Question 26

What are two defining clues for IgLON5 paraneoplastic syndrome?

Answer 26

Vocal cord dysfunction (nearly all) and parasomnias

Question 27

What does LUZP4/KLHL11 paraneoplastic syndrome typically present as?

Answer 27

Rapidly progressive MND that typically presents with flail arms. Usually secondary to testicular cancer.