Chronic Inflammatory Demyelinating Polyneuropathy (CIDP)

VERSION: 1.0 CREATED: January 29, 2026 REVISED: January 29, 2026 STATUS: Approved

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DIAGNOSIS: Chronic Inflammatory Demyelinating Polyneuropathy (CIDP)

ICD-10: G61.81 (Chronic inflammatory demyelinating polyneuritis), G61.89 (Other inflammatory polyneuropathies), G61.9 (Inflammatory polyneuropathy, unspecified)

CPT CODES: 85025 (CBC with differential), 80053 (CMP), 83036 (HbA1c), 84443 (TSH), 82607 (Vitamin B12), 86334 (Serum protein electrophoresis (SPEP)), 87389 (HIV), 80074 (Hepatitis B/C), 86235 (ANA), 86255 (Anti-MAG antibody), 86335 (Urine protein electrophoresis (UPEP)), 89051 (Cell count (tubes 1 and 4)), 84157 (Protein), 82945 (Glucose), 88104 (Cytology), 83916 (Oligoclonal bands), 95907-95913 (Nerve conduction studies (NCS)), 95886 (Electromyography (EMG)), 78816 (PET-CT), 64795 (Nerve biopsy (sural)), 96365 (IVIG (Intravenous Immunoglobulin)), 36514 (Plasma exchange (PLEX))

SYNONYMS: CIDP, chronic inflammatory demyelinating polyradiculoneuropathy, chronic relapsing polyneuropathy, chronic GBS, chronic acquired demyelinating polyneuropathy, immune-mediated neuropathy

SCOPE: Diagnosis and management of typical CIDP and CIDP variants in adults. Covers diagnostic criteria (EFNS/PNS), electrodiagnostic findings, immunotherapy options, and monitoring. Excludes acute inflammatory demyelinating polyneuropathy (Guillain-Barré syndrome), hereditary demyelinating neuropathies (CMT), and purely axonal chronic neuropathies.

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DEFINITIONS: - CIDP: Immune-mediated sensorimotor polyneuropathy with progressive or relapsing course over >8 weeks - Typical CIDP: Symmetric proximal and distal weakness, sensory involvement, areflexia - CIDP Variants: DADS (Distal Acquired Demyelinating Symmetric), MADSAM (Multifocal Acquired Demyelinating Sensory and Motor), Pure sensory CIDP, Pure motor CIDP, Focal CIDP - Treatment-dependent CIDP: Requires ongoing immunotherapy to maintain function

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DIAGNOSTIC CRITERIA (EFNS/PNS 2021):

Clinical Criteria (both required): 1. Progressive or relapsing symmetric proximal and distal weakness AND sensory dysfunction of all extremities, developing over ≥8 weeks 2. Absent or reduced deep tendon reflexes in all extremities

Supportive Clinical Features: - Response to immunotherapy - Elevated CSF protein (>45 mg/dL) with cell count <10/mm³ - MRI showing nerve root/plexus enlargement and/or enhancement

Electrodiagnostic Criteria (≥1 required): - Motor conduction velocity <80% of LLN in ≥2 nerves - Distal motor latency >125% of ULN in ≥2 nerves - F-wave latency >120% of ULN in ≥2 nerves - Conduction block: >50% amplitude reduction proximal vs distal - Temporal dispersion in ≥1 nerve

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PRIORITY KEY: STAT = Immediate | URGENT = Within hours | ROUTINE = Standard | EXT = Extended/atypical cases | - = Not applicable to this setting

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1. LABORATORY WORKUP

1A. Essential/Core Labs

Test	ED	HOSP	OPD	ICU	Rationale	Target Finding
CBC with differential (CPT 85025)	URGENT	ROUTINE	ROUTINE	-	Baseline, exclude hematologic disease	Normal
CMP (CPT 80053)	URGENT	ROUTINE	ROUTINE	-	Renal/hepatic function, glucose	Normal
HbA1c (CPT 83036)	-	ROUTINE	ROUTINE	-	Diabetes-associated neuropathy	<6.5%
TSH (CPT 84443)	-	ROUTINE	ROUTINE	-	Thyroid dysfunction	Normal
Vitamin B12 (CPT 82607)	-	ROUTINE	ROUTINE	-	Deficiency neuropathy	>400 pg/mL
Serum protein electrophoresis (SPEP) (CPT 86334)	-	ROUTINE	ROUTINE	-	Monoclonal gammopathy (MGUS, myeloma)	No M-spike
Immunofixation (serum) (CPT 86334)	-	ROUTINE	ROUTINE	-	Paraprotein identification	Negative
Free light chains (serum)	-	ROUTINE	ROUTINE	-	Light chain disease	Normal ratio

1B. Extended Workup (Second-line)

Test	ED	HOSP	OPD	ICU	Rationale	Target Finding
HIV (CPT 87389)	-	ROUTINE	ROUTINE	-	HIV-associated neuropathy	Negative
Hepatitis B/C (CPT 80074)	-	ROUTINE	ROUTINE	-	Before immunotherapy; hepatitis-associated neuropathy	Negative
ANA (CPT 86235)	-	ROUTINE	ROUTINE	-	Connective tissue disease	Negative
Anti-MAG antibody (CPT 86255)	-	ROUTINE	ROUTINE	-	MAG-associated neuropathy (DADS variant)	Negative
Anti-GM1, anti-GD1a antibodies (CPT 86255)	-	ROUTINE	ROUTINE	-	MMN, GBS variants	Negative
Anti-ganglioside panel (CPT 86255)	-	ROUTINE	ROUTINE	-	Immune-mediated neuropathies	Negative
Urine protein electrophoresis (UPEP) (CPT 86335)	-	ROUTINE	ROUTINE	-	Multiple myeloma, POEMS	Negative
VEGF level	-	EXT	EXT	-	POEMS syndrome if suspected	Normal
IgG/IgA/IgM levels	-	ROUTINE	ROUTINE	-	Before IVIG; IgA deficiency screening	Normal; document IgA level

1C. Rare/Specialized

Test	ED	HOSP	OPD	ICU	Rationale	Target Finding
Anti-NF155, anti-CNTN1, anti-Caspr1 antibodies	-	-	EXT	-	Nodal/paranodal antibody-associated CIDP	Negative
Genetic testing (PMP22, MPZ, GJB1)	-	-	EXT	-	If hereditary neuropathy suspected (CMT)	Negative
Bone marrow biopsy	-	-	EXT	-	If POEMS or myeloma suspected	Normal
Fat pad biopsy	-	-	EXT	-	Amyloidosis	Negative

LUMBAR PUNCTURE

Indication: Required for diagnostic criteria; elevated protein supports diagnosis

Study	ED	HOSP	OPD	ICU	Rationale	Target Finding
Opening pressure	-	ROUTINE	-	-	Baseline	Normal
Cell count (tubes 1 and 4) (CPT 89051)	-	ROUTINE	-	-	Exclude infection, malignancy	WBC <10/mm³ (albuminocytologic dissociation)
Protein (CPT 84157)	-	ROUTINE	-	-	Typically elevated in CIDP	Often >45-100 mg/dL
Glucose (CPT 82945)	-	ROUTINE	-	-	Infection	Normal
Cytology (CPT 88104)	-	ROUTINE	-	-	Carcinomatous meningitis	Negative
Oligoclonal bands (CPT 83916)	-	ROUTINE	-	-	MS, other inflammatory	Usually negative in CIDP

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2. DIAGNOSTIC IMAGING & STUDIES

2A. Essential/First-line

Study	ED	HOSP	OPD	ICU	Timing	Target Finding	Contraindications
Nerve conduction studies (NCS) (CPT 95907-95913)	-	URGENT	ROUTINE	-	At diagnosis	Demyelinating features (see criteria)	Anticoagulation (for needle EMG)
Electromyography (EMG) (CPT 95886)	-	URGENT	ROUTINE	-	At diagnosis	Secondary axonal changes; denervation	Same
MRI spine with contrast (cervical/lumbar)	-	ROUTINE	ROUTINE	-	At diagnosis	Nerve root enlargement/enhancement	Contrast allergy, renal disease

2B. Extended

Study	ED	HOSP	OPD	ICU	Timing	Target Finding	Contraindications
MRI brachial/lumbosacral plexus	-	ROUTINE	ROUTINE	-	If plexopathy suspected	Plexus enlargement/enhancement	Per MRI
Nerve ultrasound	-	-	ROUTINE	-	Emerging modality	Nerve enlargement (CSA increase)	None
PET-CT (CPT 78816)	-	-	EXT	-	POEMS, lymphoma, malignancy workup	Sclerotic lesions, lymphadenopathy	Per PET
Nerve biopsy (sural) (CPT 64795)	-	-	EXT	-	Diagnostic uncertainty; vasculitis suspected	Demyelination, inflammation	Rarely needed

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3. TREATMENT

3A. First-Line Immunotherapy

Treatment	Route	Indication	Dosing	Contraindications	Monitoring	ED	HOSP	OPD	ICU
IVIG (Intravenous Immunoglobulin) (CPT 96365)	IV	-	2 g/kg :: PO :: - :: Induction: 2 g/kg divided over 2-5 days; Maintenance: 0.4-1 g/kg q3-4 weeks (adjust based on response)	IgA deficiency (use IgA-depleted product), renal failure, thrombosis history	Renal function, headache, aseptic meningitis, thrombosis	-	STAT	ROUTINE	-
SCIG (Subcutaneous Immunoglobulin)	SC	-	N/A :: SC :: weekly :: Convert from IVIG at equivalent weekly dose (total monthly IVIG dose ÷ 4); administer weekly	Same (fewer systemic reactions)	Local site reactions	-	-	ROUTINE	-
Plasma exchange (PLEX) (CPT 36514)	-	-	N/A :: - :: once :: 5-7 exchanges over 2-3 weeks; 1-1.5 plasma volumes/exchange	Hemodynamic instability, line access	Hemodynamics, electrolytes (Ca, Mg), fibrinogen	-	STAT	-	-
Corticosteroids	IV	-	60-80 mg :: IV :: daily :: Prednisone 60-80 mg daily or 1 mg/kg/day × 4-8 weeks, then slow taper over 6-12 months; OR pulsed methylprednisolone 1000 mg IV × 3 days monthly	Uncontrolled DM, active infection, osteoporosis (relative)	Glucose, BP, bone density, weight, infection	-	STAT	ROUTINE	-

3B. Second-Line / Steroid-Sparing Agents

Treatment	Route	Indication	Dosing	Contraindications	Monitoring	ED	HOSP	OPD	ICU
Azathioprine	PO	-	50 mg :: PO :: daily :: Start 50 mg daily; increase by 50 mg q2 weeks to 2-3 mg/kg/day	TPMT deficiency (check before starting), pregnancy	CBC, LFTs, TPMT level	-	ROUTINE	ROUTINE	-
Mycophenolate mofetil	PO	-	500 mg :: PO :: BID :: Start 500 mg BID; increase to 1000-1500 mg BID	Pregnancy, severe GI disease	CBC, LFTs	-	ROUTINE	ROUTINE	-
Rituximab	IV	-	375 mg :: IV :: PRN :: 375 mg/m² IV weekly × 4 OR 1000 mg IV × 2 doses (days 1 and 15); repeat q6 months PRN	Active infection, hepatitis B (screen)	Infusion reactions, infection, B-cell counts	-	-	ROUTINE	-
Cyclophosphamide	IV	-	500-1000 mg :: IV :: monthly :: Pulse: 500-1000 mg/m² IV monthly × 6; rarely used due to toxicity	Severe cytopenias, active infection	CBC, renal function, bladder toxicity	-	-	EXT	-
Cyclosporine	PO	-	3-5 mg/kg :: PO :: - :: 3-5 mg/kg/day in 2 divided doses; target trough 100-200 ng/mL	Renal impairment, uncontrolled HTN	Renal function, BP, drug levels	-	-	EXT	-

3C. Anti-Nodal Antibody-Positive CIDP (Special Population)

Treatment	Route	Indication	Dosing	Contraindications	Monitoring	ED	HOSP	OPD	ICU
Rituximab (first-line for anti-nodal CIDP)	PO	-	375 mg :: PO :: - :: 375 mg/m² weekly × 4 OR 1000 mg × 2 doses	Per above	Poor response to IVIG expected; rituximab preferred	-	-	ROUTINE	-

3D. Symptomatic Treatment

Treatment	Route	Indication	Dosing	Pre-Treatment Requirements	Contraindications	Monitoring	ED	HOSP	OPD	ICU
Gabapentin (neuropathic pain)	PO	-	100-300 mg :: PO :: TID :: Start 100-300 mg TID; titrate to 900-3600 mg/day	-	Renal impairment (adjust)	Sedation, dizziness	-	ROUTINE	ROUTINE	-
Pregabalin (neuropathic pain)	PO	-	75 mg :: PO :: BID :: Start 75 mg BID; titrate to 150-300 mg BID	-	Renal impairment (adjust)	Same	-	ROUTINE	ROUTINE	-
Duloxetine (neuropathic pain)	PO	-	30 mg :: PO :: daily :: Start 30 mg daily; increase to 60 mg daily	-	Severe hepatic/renal impairment, MAOIs	Nausea, BP	-	ROUTINE	ROUTINE	-
Amitriptyline (neuropathic pain)	-	-	10-25 mg :: PO :: QHS :: Start 10-25 mg QHS; titrate to 50-100 mg QHS	-	Cardiac arrhythmia, glaucoma	QTc, anticholinergic effects	-	ROUTINE	ROUTINE	-

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4. OTHER RECOMMENDATIONS

4A. Referrals & Consults

Recommendation	ED	HOSP	OPD	ICU	Indication
Neuromuscular specialist	-	ROUTINE	ROUTINE	-	All patients; diagnosis confirmation and management
Physical therapy	-	ROUTINE	ROUTINE	-	Strengthening, gait training, fall prevention
Occupational therapy	-	ROUTINE	ROUTINE	-	ADL assistance, adaptive equipment
Physiatry/PM&R	-	-	ROUTINE	-	Comprehensive rehabilitation, orthotics
Hematology/Oncology	-	-	ROUTINE	-	If monoclonal gammopathy or POEMS
Infusion center	-	-	ROUTINE	-	IVIG administration
Home health nursing	-	-	ROUTINE	-	SCIG training
Pain management	-	-	ROUTINE	-	Refractory neuropathic pain

4B. Patient/Family Instructions

Recommendation	ED	HOSP	OPD
CIDP is a chronic condition requiring ongoing treatment; not curable but manageable	-	ROUTINE	ROUTINE
IVIG infusions will be needed regularly (typically monthly)	-	ROUTINE	ROUTINE
Report any worsening weakness, numbness, or falls immediately	-	ROUTINE	ROUTINE
Do NOT stop immunotherapy abruptly without physician guidance	-	ROUTINE	ROUTINE
Fall prevention: remove rugs, improve lighting, use assistive devices	-	ROUTINE	ROUTINE
Vaccination guidelines: avoid live vaccines on immunosuppression; IVIG may interfere with vaccine response	-	ROUTINE	ROUTINE
Keep all neurology follow-up appointments for monitoring	-	ROUTINE	ROUTINE
GBS Foundation and similar resources for support	-	-	ROUTINE

4C. Lifestyle & Prevention

Recommendation	ED	HOSP	OPD
Regular exercise within tolerance	-	ROUTINE	ROUTINE
Balance and fall prevention strategies	-	ROUTINE	ROUTINE
Foot care (sensory loss increases injury risk)	-	ROUTINE	ROUTINE
Avoid excessive alcohol	-	ROUTINE	ROUTINE
Maintain healthy weight	-	ROUTINE	ROUTINE

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5. DIFFERENTIAL DIAGNOSIS

Alternative Diagnosis	Key Distinguishing Features	Tests to Differentiate
Guillain-Barré syndrome (GBS)	Acute onset (<4 weeks), monophasic, nadir within 4 weeks	Timing; CIDP requires >8 weeks progression
Multifocal motor neuropathy (MMN)	Pure motor, asymmetric, conduction block, anti-GM1+	Anti-GM1; no sensory involvement; does not respond to steroids
POEMS syndrome	Polyneuropathy, organomegaly, endocrinopathy, M-protein, skin changes	VEGF elevated; sclerotic bone lesions; lambda light chain
CMT (Charcot-Marie-Tooth)	Family history, foot deformities (pes cavus), slow progression since childhood	Genetic testing; no CSF protein elevation
MAG-associated neuropathy	Distal, sensory predominant, IgM paraprotein, anti-MAG positive	Anti-MAG antibody; IgM gammopathy
Diabetic lumbosacral radiculoplexus neuropathy	Diabetes, weight loss, severe pain, proximal > distal	Clinical; self-limited course
Vasculitic neuropathy	Painful, asymmetric, mononeuritis multiplex pattern	ESR/CRP elevated; nerve/muscle biopsy
Amyloidosis	Autonomic dysfunction, carpal tunnel, heart failure, neuropathy	Fat pad/nerve biopsy; SPEP
Lymphoma/carcinomatous neuropathy	Weight loss, lymphadenopathy, progressive	Imaging; CSF cytology

6. MONITORING PARAMETERS

Parameter	ED	HOSP	OPD	ICU	Frequency	Target/Threshold	Action if Abnormal
MRC strength grading	-	Daily	Each visit	-	Each visit	Stable or improving	Adjust immunotherapy
Functional scales (INCAT, ODSS)	-	Weekly	Each visit	-	q3 months	Stable or improving	Adjust treatment
Grip strength (dynamometry)	-	-	ROUTINE	-	q3 months	Stable or improving	Objective measure
NCS/EMG	-	-	ROUTINE	-	q6-12 months or with change	Stable or improving	Treatment response
Renal function (IVIG patients)	-	ROUTINE	ROUTINE	-	Before each IVIG; q3 months	Stable creatinine	Hold/reduce IVIG if rising
IgG trough level	-	-	ROUTINE	-	q3-6 months	Therapeutic (target varies)	Adjust IVIG dose
Glucose (steroid patients)	-	Daily	Each visit	-	Per steroid use	<200 mg/dL	Adjust DM meds
Bone density (steroid patients)	-	-	ROUTINE	-	At baseline, q1-2 years	T-score >-2.5	Calcium, vitamin D, bisphosphonate
CBC (immunosuppression)	-	Weekly	q3 months	-	Per agent	Normal counts	Adjust dose
Weight, BP (steroids)	-	Daily	Each visit	-	Per steroid use	Stable	Address

7. DISPOSITION CRITERIA

Disposition	Criteria
Outpatient management	Most patients; stable disease, able to ambulate, no respiratory concerns
Admit to hospital	New diagnosis requiring urgent workup, significant weakness (unable to walk), respiratory concerns, severe relapse
ICU admission	Respiratory failure (FVC <20 mL/kg, NIF <-30 cmH2O), hemodynamic instability
Discharge from hospital	Diagnosis established, treatment initiated, functionally stable, follow-up arranged
Long-term monitoring	Every 3-6 months with neuromuscular specialist; more frequent if unstable

8. EVIDENCE & REFERENCES

Recommendation	Evidence Level	Source
EFNS/PNS Diagnostic Criteria	Class I	Van den Bergh et al., Eur J Neurol 2021
IVIG effective for CIDP	Class I, Level A	ICE trial (Hughes et al., Lancet Neurol 2008); Cochrane Reviews (Eftimov et al., 2013)
SCIG non-inferior to IVIG	Class I, Level A	PATH trial (van Schaik et al., Lancet Neurol 2018)
Corticosteroids effective for CIDP	Class I, Level A	Cochrane Reviews
Plasma exchange effective	Class I, Level A	Cochrane Reviews
IVIG, steroids, PLEX equivalent efficacy	Class I	Multiple comparative studies
Rituximab for anti-nodal CIDP	Class II, Level B	Case series; expert consensus
Steroid-sparing agents	Class II-III, Level C	Limited controlled data

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NOTES

• CIDP requires >8 weeks of progression to distinguish from GBS
• Albuminocytologic dissociation (elevated protein, normal cells) typical but not universal
• Three first-line treatments: IVIG, steroids, PLEX - choose based on patient factors
• IVIG preferred if rapid response needed, steroid side effects concern, or patient preference
• Steroids preferred if cost is major factor; pulsed IV may have fewer side effects than daily oral
• Many patients are "treatment-dependent" requiring indefinite maintenance therapy
• Anti-nodal antibody-positive CIDP (NF155, CNTN1, Caspr1) responds poorly to IVIG but well to rituximab
• Monitor for IVIG-related complications: renal impairment, thrombosis, aseptic meningitis
• Slow taper of any immunotherapy to identify minimum effective dose

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CHANGE LOG

v1.0 (January 29, 2026) - Initial template creation - EFNS/PNS 2021 criteria included - First-line (IVIG, steroids, PLEX) and second-line immunotherapy - Anti-nodal antibody section - CIDP variants mentioned