Click cells to mark EAN/PNS 2021 criteria for each nerve (including criterion G for prolonged distal CMAP). Minimum: 2 criteria in different nerves for CIDP.
| Criterion | Definition | Median | Ulnar | Fibular | Tibial | |
|---|---|---|---|---|---|---|
| A | Distal latency | Prolonged ≥50% (1.5×) upper limit | ||||
| B | Conduction velocity | Reduced ≥30% (0.7×) lower limit | ||||
| C | F-wave latency |
CMAP ≥80% LLN → F prolonged ≥20%
CMAP <80% LLN → F prolonged ≥50%
|
||||
| D | Absent F waves | Absent with CMAP amplitude ≥20% lower limit | ||||
| E | Partial motor CB | Proximal × distal CMAP amplitude reduced ≥30% (excl. Tibial) | N/A | |||
| F | Pathological temporal dispersion | Proximal × distal CMAP duration increased >30% (≥100% on tibial) | ||||
| G | Distal CMAP duration |
Negative peak with prolonged onset–termination interval:
Filter (LFF):
|
||||
| Positive criteria per nerve | 0 | 0 | 0 | 0 | ||
CTS - carpal tunnel syndrome · UNe - ulnar neuropathy at the elbow · MGA - Martin-Gruber anastomosis · CB - conduction block
Sensory Checklist — EAN/PNS 2021 Criteria
A major 2021 guideline change was elevating sensory conduction studies to a mandatory criterion for typical CIDP — previously only supportive in 2010. This checklist complements motor assessment above.
1. Sensory clinical filter (typical CIDP)
2. Sensory electrophysiological criteria (EMG/NCS)
Abnormality = prolonged distal latency, reduced SCV, or reduced SNAP amplitude.
3. Variant: pure sensory CIDP
4. Sensory red flags
The presence of any item below should raise suspicion for an alternative diagnosis.
📑 Executive Summary: EAN/PNS 2021 Guidelines on CIDP Diagnosis
The second revision of the joint guideline by the European Academy of Neurology (EAN) and the Peripheral Nerve Society (PNS) (published in the European Journal of Neurology and Journal of the Peripheral Nervous System) establishes the global gold standard for the clinical and electrodiagnostic diagnosis of Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP). The primary focus of this update and its Official Errata (December 2021) was to strictly increase diagnostic specificity, thereby curbing misdiagnosis (false positives) and preventing unnecessary immunotherapy.
🔍 Key Electrodiagnostic (NCS) Highlights
- Mandatory Sensory Involvement: Requires proven conduction abnormalities in ≥ 2 sensory nerves (or the classic sural sparing pattern).
- Tibial Nerve Exclusion in CB: Partial motor conduction block (≥ 30% reduction) explicitly excludes the tibial nerve to avoid distal compression artifacts.
- Filter Standardization (LFF): Distal CMAP duration thresholds are standardized according to low-frequency filter settings (recommending LFF 5 Hz).
⚠️ Classification & CIDP Mimics
- Possible CIDP (1 Motor Nerve): Demyelination in only 1 motor nerve requires mandatory supportive criteria (USG, CSF, MRI) or objective treatment response.
- Exclusion of Nodopathies: Paranodal antibodies (Anti-NF155, CNTN1, Caspr1) and CISP are now classified separately due to poor response to IVIg.
- Neuromuscular Ultrasound: Officially incorporated as a powerful supportive biomarker identifying cross-sectional area (CSA) enlargement.
This calculator strictly automates all normative thresholds and mathematical criteria established by the 2021 joint guidelines of the European Academy of Neurology (EAN) and the Peripheral Nerve Society (PNS).
1. Diagnostic Categories
The 2021 guideline removed "Probable" and simplified to two certainty levels:
CIDP
Clinical criteria + electrophysiological evidence (motor conduction criteria met in at least two nerves + abnormality in at least two sensory nerves or *sural sparing*).
Possible CIDP
Clinical criteria + electrophysiological evidence in only one motor nerve (and abnormality in at least two sensory nerves or *sural sparing*). Requires at least one supportive criterion for confirmation.
2. Clinical Filter
Typical CIDP (50–60% of cases)
- Progression: progressive worsening, stepwise or relapsing over > 8 weeks.
- Weakness: symmetric, proximal and distal, in upper and lower limbs.
- Reflexes: global hyporeflexia or areflexia.
- Sensory: associated large-fiber sensory dysfunction.
Recognized Variants
Distal · Multifocal (MADSAM / Lewis-Sumner) · Focal · Pure motor · Pure sensory.
Note: CISP (Chronic immune sensory polyradiculopathy) and autoimmune nodopathies were excluded from the CIDP umbrella in this guideline due to distinct pathophysiology and treatment response.
3. Motor Electrophysiology (EMG/NCS)
The major 2021 change was elevating sensory conduction to a mandatory criterion for typical CIDP. Motor demyelination parameters seek:
- Distal latency: prolongation > 50% above ULN.
- MCV: reduction ≥ 30% below LLN.
- F waves: prolongation ≥ 20% above ULN (if distal CMAP ≥ 80% LLN) or ≥ 50% (if distal CMAP < 80% LLN), or absence.
- Conduction block: area/amplitude reduction ≥ 30% (excluding the Tibial nerve).
- Temporal dispersion: duration increase > 30% (≥ 100% on the Tibial nerve).
Changes in at least two sensory nerves (prolonged latencies, reduced amplitudes, or slowing) are now required. Sural sparing with upper-limb sensory abnormality remains a valuable marker.
Distal CMAP duration thresholds (criterion G) in **LFF 5 Hz** (default initial): Median > 8.0 ms · Ulnar > 8.6 ms · Peroneal > 8.5 ms · Tibial > 8.3 ms.
Distal CMAP Duration Prolongation Threshold Table (Criterion G):
Low Frequency Filter (LFF)
Median n.
Ulnar n.
Peroneal n.
Tibial n.
LFF 2 Hz
> 8.4 ms
> 9.6 ms
> 8.8 ms
> 9.2 ms
LFF 5 Hz (Calc Default)
> 8.0 ms
> 8.6 ms
> 8.5 ms
> 8.3 ms
LFF 10 Hz
> 7.8 ms
> 8.5 ms
> 8.3 ms
> 8.2 ms
LFF 20 Hz
> 7.4 ms
> 7.8 ms
> 8.1 ms
> 8.0 ms
4. Supportive Criteria
Required to confirm CIDP from the "Possible CIDP" category:
Therapeutic CriterionObjective measurable improvement (strength, INCAT, I-RODS, dynamometry) after IVIg, plasmapheresis, or corticosteroids.
Neuromuscular Ultrasound2021 guideline addition: focal/diffuse increase in CSA (cross-sectional area) of nerves (proximal median, ulnar, brachial plexus).
CSFProtein–cell dissociation. Caution in diabetics and elderly (require > 100 mg/dL). Cells > 50/mm³ should raise suspicion of alternative causes (HIV, Lyme).
MRIGadolinium enhancement or thickening of cervical, lumbosacral roots, or plexuses.
BiopsyReserved for refractory atypical cases: macrophage-induced demyelination/remyelination signs and onion bulbs.
5. Mimickers and Red Flags
Absence of alternative explanation is fundamental. New guidelines strongly recommend:
- Monoclonal protein screening (serum, urine, and free light chains) in all adults. Presence of IgM with distal phenotype suggests DADS / anti-MAG neuropathy - a distinct diagnosis with different treatment.
- Autoimmune nodopathies/paranodopathies (anti-NF155, CNTN1, Caspr1): suspect in patients with disproportionate pain, tremor, severe ataxia, or early refractoriness to IVIg.
- POEMS syndrome: screen serum VEGF and lambda paraprotein in cases with organomegaly, edema, or systemic manifestations.
References and Erratas:
· van den Bergh PYK, van Doorn PA, Hadden RDM, et al. European Academy of Neurology/Peripheral Nerve Society Guideline on diagnosis and treatment of chronic inflammatory demyelinating polyradiculoneuropathy: Report of a joint Task Force - Second revision. Eur J Neurol. 2021;28(11):3556–3583. doi:10.1111/ene.15056.
· Official Errata of December 18, 2021: Rectification of sensory criteria for Possible CIDP in Table 3. Eur J Neurol. doi:10.1111/ene.15233.
· Doneddu PE, Bril V, Dalakas MC, et al. Electrodiagnostic criteria for CIDP: classification accuracy and comparison with other criteria. J Neurol Neurosurg Psychiatry. 2022;93(1):48–55. doi:10.1136/jnnp-2021-326599.
📑 Executive Summary: EAN/PNS 2021 Guidelines on CIDP Diagnosis
The second revision of the joint guideline by the European Academy of Neurology (EAN) and the Peripheral Nerve Society (PNS) (published in the European Journal of Neurology and Journal of the Peripheral Nervous System) establishes the global gold standard for the clinical and electrodiagnostic diagnosis of Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP). The primary focus of this update and its Official Errata (December 2021) was to strictly increase diagnostic specificity, thereby curbing misdiagnosis (false positives) and preventing unnecessary immunotherapy.
🔍 Key Electrodiagnostic (NCS) Highlights
- Mandatory Sensory Involvement: Requires proven conduction abnormalities in ≥ 2 sensory nerves (or the classic sural sparing pattern).
- Tibial Nerve Exclusion in CB: Partial motor conduction block (≥ 30% reduction) explicitly excludes the tibial nerve to avoid distal compression artifacts.
- Filter Standardization (LFF): Distal CMAP duration thresholds are standardized according to low-frequency filter settings (recommending LFF 5 Hz).
⚠️ Classification & CIDP Mimics
- Possible CIDP (1 Motor Nerve): Demyelination in only 1 motor nerve requires mandatory supportive criteria (USG, CSF, MRI) or objective treatment response.
- Exclusion of Nodopathies: Paranodal antibodies (Anti-NF155, CNTN1, Caspr1) and CISP are now classified separately due to poor response to IVIg.
- Neuromuscular Ultrasound: Officially incorporated as a powerful supportive biomarker identifying cross-sectional area (CSA) enlargement.
This calculator strictly automates all normative thresholds and mathematical criteria established by the 2021 joint guidelines of the European Academy of Neurology (EAN) and the Peripheral Nerve Society (PNS).
1. Diagnostic Categories
The 2021 guideline removed "Probable" and simplified to two certainty levels:
CIDP
Clinical criteria + electrophysiological evidence (motor conduction criteria met in at least two nerves + abnormality in at least two sensory nerves or *sural sparing*).
Possible CIDP
Clinical criteria + electrophysiological evidence in only one motor nerve (and abnormality in at least two sensory nerves or *sural sparing*). Requires at least one supportive criterion for confirmation.
2. Clinical Filter
Typical CIDP (50–60% of cases)
- Progression: progressive worsening, stepwise or relapsing over > 8 weeks.
- Weakness: symmetric, proximal and distal, in upper and lower limbs.
- Reflexes: global hyporeflexia or areflexia.
- Sensory: associated large-fiber sensory dysfunction.
Recognized Variants
Distal · Multifocal (MADSAM / Lewis-Sumner) · Focal · Pure motor · Pure sensory.
Note: CISP (Chronic immune sensory polyradiculopathy) and autoimmune nodopathies were excluded from the CIDP umbrella in this guideline due to distinct pathophysiology and treatment response.
3. Motor Electrophysiology (EMG/NCS)
The major 2021 change was elevating sensory conduction to a mandatory criterion for typical CIDP. Motor demyelination parameters seek:
- Distal latency: prolongation > 50% above ULN.
- MCV: reduction ≥ 30% below LLN.
- F waves: prolongation ≥ 20% above ULN (if distal CMAP ≥ 80% LLN) or ≥ 50% (if distal CMAP < 80% LLN), or absence.
- Conduction block: area/amplitude reduction ≥ 30% (excluding the Tibial nerve).
- Temporal dispersion: duration increase > 30% (≥ 100% on the Tibial nerve).
Changes in at least two sensory nerves (prolonged latencies, reduced amplitudes, or slowing) are now required. Sural sparing with upper-limb sensory abnormality remains a valuable marker.
Distal CMAP duration thresholds (criterion G) in **LFF 5 Hz** (default initial): Median > 8.0 ms · Ulnar > 8.6 ms · Peroneal > 8.5 ms · Tibial > 8.3 ms.
Distal CMAP Duration Prolongation Threshold Table (Criterion G):
| Low Frequency Filter (LFF) | Median n. | Ulnar n. | Peroneal n. | Tibial n. |
|---|---|---|---|---|
| LFF 2 Hz | > 8.4 ms | > 9.6 ms | > 8.8 ms | > 9.2 ms |
| LFF 5 Hz (Calc Default) | > 8.0 ms | > 8.6 ms | > 8.5 ms | > 8.3 ms |
| LFF 10 Hz | > 7.8 ms | > 8.5 ms | > 8.3 ms | > 8.2 ms |
| LFF 20 Hz | > 7.4 ms | > 7.8 ms | > 8.1 ms | > 8.0 ms |
4. Supportive Criteria
Required to confirm CIDP from the "Possible CIDP" category:
5. Mimickers and Red Flags
Absence of alternative explanation is fundamental. New guidelines strongly recommend:
- Monoclonal protein screening (serum, urine, and free light chains) in all adults. Presence of IgM with distal phenotype suggests DADS / anti-MAG neuropathy - a distinct diagnosis with different treatment.
- Autoimmune nodopathies/paranodopathies (anti-NF155, CNTN1, Caspr1): suspect in patients with disproportionate pain, tremor, severe ataxia, or early refractoriness to IVIg.
- POEMS syndrome: screen serum VEGF and lambda paraprotein in cases with organomegaly, edema, or systemic manifestations.
References and Erratas:
· van den Bergh PYK, van Doorn PA, Hadden RDM, et al. European Academy of Neurology/Peripheral Nerve Society Guideline on diagnosis and treatment of chronic inflammatory demyelinating polyradiculoneuropathy: Report of a joint Task Force - Second revision. Eur J Neurol. 2021;28(11):3556–3583. doi:10.1111/ene.15056.
· Official Errata of December 18, 2021: Rectification of sensory criteria for Possible CIDP in Table 3. Eur J Neurol. doi:10.1111/ene.15233.
· Doneddu PE, Bril V, Dalakas MC, et al. Electrodiagnostic criteria for CIDP: classification accuracy and comparison with other criteria. J Neurol Neurosurg Psychiatry. 2022;93(1):48–55. doi:10.1136/jnnp-2021-326599.
EAN/PNS 2021 electrodiagnostic criteria for CIDP
Interactive checklist of EAN/PNS 2021 criteria for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP): demyelination features in median, ulnar, peroneal and tibial nerves.
📑 Executive Summary: EAN/PNS 2021 Guidelines on CIDP Diagnosis
The second revision of the joint guideline by the European Academy of Neurology (EAN) and the Peripheral Nerve Society (PNS) (published in the European Journal of Neurology and Journal of the Peripheral Nervous System) establishes the global gold standard for the clinical and electrodiagnostic diagnosis of Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP). The primary focus of this update and its Official Errata (December 2021) was to strictly increase diagnostic specificity, thereby curbing misdiagnosis (false positives) and preventing unnecessary immunotherapy.
🔍 Key Electrodiagnostic (NCS) Highlights
- Mandatory Sensory Involvement: Requires proven conduction abnormalities in ≥ 2 sensory nerves (or the classic sural sparing pattern).
- Tibial Nerve Exclusion in CB: Partial motor conduction block (≥ 30% reduction) explicitly excludes the tibial nerve to avoid distal compression artifacts.
- Filter Standardization (LFF): Distal CMAP duration thresholds are standardized according to low-frequency filter settings (recommending LFF 5 Hz).
⚠️ Classification & CIDP Mimics
- Possible CIDP (1 Motor Nerve): Demyelination in only 1 motor nerve requires mandatory supportive criteria (USG, CSF, MRI) or objective treatment response.
- Exclusion of Nodopathies: Paranodal antibodies (Anti-NF155, CNTN1, Caspr1) and CISP are now classified separately due to poor response to IVIg.
- Neuromuscular Ultrasound: Officially incorporated as a powerful supportive biomarker identifying cross-sectional area (CSA) enlargement.
This calculator strictly automates all normative thresholds and mathematical criteria established by the 2021 joint guidelines of the European Academy of Neurology (EAN) and the Peripheral Nerve Society (PNS).
1. Diagnostic Categories
The 2021 guideline removed "Probable" and simplified to two certainty levels:
CIDP
Clinical criteria + electrophysiological evidence (motor conduction criteria met in at least two nerves + abnormality in at least two sensory nerves or *sural sparing*).
Possible CIDP
Clinical criteria + electrophysiological evidence in only one motor nerve (and abnormality in at least two sensory nerves or *sural sparing*). Requires at least one supportive criterion for confirmation.
2. Clinical Filter
Typical CIDP (50–60% of cases)
- Progression: progressive worsening, stepwise or relapsing over > 8 weeks.
- Weakness: symmetric, proximal and distal, in upper and lower limbs.
- Reflexes: global hyporeflexia or areflexia.
- Sensory: associated large-fiber sensory dysfunction.
Recognized Variants
Distal · Multifocal (MADSAM / Lewis-Sumner) · Focal · Pure motor · Pure sensory.
Note: CISP (Chronic immune sensory polyradiculopathy) and autoimmune nodopathies were excluded from the CIDP umbrella in this guideline due to distinct pathophysiology and treatment response.
3. Motor Electrophysiology (EMG/NCS)
The major 2021 change was elevating sensory conduction to a mandatory criterion for typical CIDP. Motor demyelination parameters seek:
- Distal latency: prolongation > 50% above ULN.
- MCV: reduction ≥ 30% below LLN.
- F waves: prolongation ≥ 20% above ULN (if distal CMAP ≥ 80% LLN) or ≥ 50% (if distal CMAP < 80% LLN), or absence.
- Conduction block: area/amplitude reduction ≥ 30% (excluding the Tibial nerve).
- Temporal dispersion: duration increase > 30% (≥ 100% on the Tibial nerve).
Changes in at least two sensory nerves (prolonged latencies, reduced amplitudes, or slowing) are now required. Sural sparing with upper-limb sensory abnormality remains a valuable marker.
Distal CMAP duration thresholds (criterion G) in **LFF 5 Hz** (default initial): Median > 8.0 ms · Ulnar > 8.6 ms · Peroneal > 8.5 ms · Tibial > 8.3 ms.
Distal CMAP Duration Prolongation Threshold Table (Criterion G):
| Low Frequency Filter (LFF) | Median n. | Ulnar n. | Peroneal n. | Tibial n. |
|---|---|---|---|---|
| LFF 2 Hz | > 8.4 ms | > 9.6 ms | > 8.8 ms | > 9.2 ms |
| LFF 5 Hz (Calc Default) | > 8.0 ms | > 8.6 ms | > 8.5 ms | > 8.3 ms |
| LFF 10 Hz | > 7.8 ms | > 8.5 ms | > 8.3 ms | > 8.2 ms |
| LFF 20 Hz | > 7.4 ms | > 7.8 ms | > 8.1 ms | > 8.0 ms |
4. Supportive Criteria
Required to confirm CIDP from the "Possible CIDP" category:
5. Mimickers and Red Flags
Absence of alternative explanation is fundamental. New guidelines strongly recommend:
- Monoclonal protein screening (serum, urine, and free light chains) in all adults. Presence of IgM with distal phenotype suggests DADS / anti-MAG neuropathy - a distinct diagnosis with different treatment.
- Autoimmune nodopathies/paranodopathies (anti-NF155, CNTN1, Caspr1): suspect in patients with disproportionate pain, tremor, severe ataxia, or early refractoriness to IVIg.
- POEMS syndrome: screen serum VEGF and lambda paraprotein in cases with organomegaly, edema, or systemic manifestations.
References and Erratas:
· van den Bergh PYK, van Doorn PA, Hadden RDM, et al. European Academy of Neurology/Peripheral Nerve Society Guideline on diagnosis and treatment of chronic inflammatory demyelinating polyradiculoneuropathy: Report of a joint Task Force - Second revision. Eur J Neurol. 2021;28(11):3556–3583. doi:10.1111/ene.15056.
· Official Errata of December 18, 2021: Rectification of sensory criteria for Possible CIDP in Table 3. Eur J Neurol. doi:10.1111/ene.15233.
· Doneddu PE, Bril V, Dalakas MC, et al. Electrodiagnostic criteria for CIDP: classification accuracy and comparison with other criteria. J Neurol Neurosurg Psychiatry. 2022;93(1):48–55. doi:10.1136/jnnp-2021-326599.
Perguntas frequentes
What are the EAN/PNS 2021 electrodiagnostic criteria for CIDP?
Include increased distal latency, reduced velocity, prolonged F-wave latency, temporal conduction block and abnormal dispersion in specified nerves per EAN/PNS 2021.
How many nerves must meet criteria?
Depends on clinical certainty level; the checklist applies EAN/PNS 2021 thresholds for possible/probable CIDP.