Mendell listed criteria for chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP). These are based on the criteria of Barohn et al and the Ad Hoc Subcommittee of the American Academy of Neurology. The author is from the Ohio State University.



(1) mandatory clinical features

(2) major laboratory features

(3) mandatory exclusion criteria





2 of 2

3 of 2

4 of 4


2 of 2

2 of 3

4 of 4


2 of 2

1 of 3

4 of 4



Mandatory clinical features:

(1) progression of muscle weakness in distal and proximal muscles of the upper and lower extremities for >= 2 months (8 weeks)

(2) hypo- or a-reflexia


Major laboratory features:

(1) electrophysiologic findings - 3 or 4 of the following:

(1a) reduction of nerve conduction velocity in 2 or more motor nerves

(1b) partial conduction block or temporal dispersion in 1 or more motor nerves

(1c) prolonged distal latencies in 2 or more nerves

(1d) absent or prolonged F wave latencies in at least 2 motor nerves

(2) CSF showing elevated protein (> 55 mg/dL) and white blood cell count < 10 per µL.

(3) demyelination as the primary finding in a nerve biopsy




nerve conduction

< 80% of lower limit of normal (LLN) if amplitude > 80% of LLN; < 70% of LLN if amplitude < 80% of LLN

partial conduction block (CB)

> 20% drop in negative peak (-p) area or peak-to-peak (p-p) amplitude between proximal and distal sites of nerve stimulation with < 15% change in -p duration

temporal dispersion (TD)

> 20% drop in negative peak (-p) area or peak-to-peak (p-p) amplitude; -p duration exceeds 15%

distal latencies

> 125% of the upper limit of normal (ULN) if amplitude > 80% LLN; > 150% of ULN if amplitude < 80% LLN

F wave latency

> 125% of the upper limit of normal (ULN) if amplitude > 80% LLN; > 150% of ULN if amplitude < 80% LLN


All of these must be absent (exclusions):

(1) clinical findings: pure sensory neuropathy, mutilation of hands or feet, retinitis pigmentosa, ichthyosis, orange tonsils, history of exposure to toxins or drugs causing peripheral neuropathy

(2) laboratory findings: low serum cholesterol concentration, evidence of porphyria, hypothyroidism, heavy metal poisoning, CSF WBC cell count > 50 per µL, low serum vitamin B12 concentration, diabetes mellitus (fasting glucose >= 7.7 mmol/L)

(3) nerve biopsy: vasculitis, neurofilamentous swollen axons, intramyelinic blebs, amyloid deposits, deposits in Schwann cells consistent with Fabry's disease, adrenal leukodystrophy, metachromatic leukodystrophy, globoid cell leukodystrophy, Refsum disease

(4) electrodiagnostic features: neuromuscular transmission defect, myopathy, anterior horn disease


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