Synopsis
Identify chronic or relapsing immune demyelinating neuropathy, require electroclinical concordance before long-term treatment, and monitor objective response to IVIg, corticosteroids or plasma exchange.
- Typical CIDP causes progressive or relapsing symmetrical proximal and distal weakness, sensory loss and reduced or absent reflexes over at least 8 weeks.
- The time course distinguishes it from monophasic GBS, although acute-onset CIDP can initially reach severe weakness quickly and declare itself through later progression or relapses.
- Nerve-conduction evidence of acquired demyelination across multiple nerves is central: conduction block, temporal dispersion, prolonged distal latencies and slowed velocities must meet validated criteria.
- Raised CSF protein with few cells supports CIDP but is neither required nor specific, especially with older age, diabetes or spinal disease.
- Exclude paraproteinaemic, hereditary, toxic, diabetic, amyloid, POEMS, anti-MAG and nodal or paranodal antibody disorders because treatment response and prognosis differ.
- First-line disease-modifying options are IV immunoglobulin, corticosteroids or plasma exchange; IVIg is generally preferred initially for motor CIDP because steroids can worsen some cases.
- After response, individualise IVIg or subcutaneous immunoglobulin maintenance interval and dose; end-of-dose symptoms alone should be confirmed with objective measures.
- Use grip strength, MRC sum score, INCAT or another disability scale and timed function before and after therapy to prevent placebo-driven diagnosis and overtreatment.
- Failure to improve should trigger re-evaluation of diagnosis, dose and irreversible axonal loss rather than indefinite escalation of expensive and risky immunotherapy.
Key red flags
An apparent GBS episode that continues progressing beyond 8 weeks or has repeated treatment-related deteriorations may evolve into a chronic immune neuropathy.
Weakness with little sensory loss can represent motor CIDP, but motor neurone disease and multifocal motor neuropathy require careful exclusion.
Monoclonal protein, severe pain, weight loss, autonomic failure, family foot deformity or poor objective treatment response raises amyloid, POEMS, anti-MAG, hereditary or other disease.
Investigation priorities
Demonstrate acquired demyelination across sufficient nerves and quantify secondary axonal loss.
Management branches
Chronic or relapsing areflexic weakness raises possible CIDP.
- Document more-than-8-week tempo, proximal and distal power, sensory modalities, reflexes, gait and alternative central or motor-neurone signs.
- Obtain expert nerve conduction using validated demyelination criteria and repeat or expand testing when the first study is technically limited.
- Screen paraprotein, diabetes, B12, thyroid, renal, liver, infection, hereditary and amyloid clues, using CSF and imaging only as supportive evidence.
- Record objective strength and disability before treatment so a response cannot retroactively become the only diagnostic criterion.
Probable or definite CIDP causes meaningful progression or disability.
- Choose IVIg, corticosteroid or plasma exchange with specialist advice based on motor phenotype, speed, diabetes, thrombotic or renal risk, access and preference.
- Use IVIg preferentially for pure motor disease and for rapid practical response where appropriate, following NHS commissioned dosing governance.
- Measure strength and disability at a predefined interval and classify improvement, stability or failure against the documented baseline.