Makindo Medical Notes

⚡ Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) is an immune-mediated neuropathy, considered the chronic counterpart of Guillain-Barré Syndrome (GBS). 🔑 Unlike GBS, it is treatable and steroid-responsive, making early recognition crucial.

🧾 About

• Definition: CIDP is a chronic or relapsing demyelinating polyneuropathy causing progressive weakness and sensory loss.
• Onset: Evolves over ≥8 weeks (contrast with GBS which is acute < 4 weeks).
• Key Feature: Symmetrical motor > sensory involvement with areflexia.

🧬 Aetiology

• Immune-mediated attack on peripheral nerve myelin, leading to conduction block and axonal dysfunction.
• Inflammatory infiltrates and segmental demyelination with onion-bulb formations on biopsy 🧅.

🔗 Associations

• Infections: HIV, HBV, HCV.
• Haematological: MGUS, Myeloma 🩸.
• Autoimmune: MS, SLE, Diabetes mellitus.
• Other: IBD, Pregnancy 🤰.

🩺 Clinical Presentation

• Weakness: Symmetrical proximal and distal weakness (difficulty climbing stairs or rising from a chair).
• Sensory: Numbness, tingling, distal sensory loss; sensory ataxia may be evident.
• Areflexia: Reflexes absent or markedly reduced.
• Tremor: Postural tremor in some patients.
• Cranial nerves: Rarely affected; if present, usually facial weakness.
• Course: Either steadily progressive or relapsing–remitting.

💡 Helpful Clinical Pointers

• Upper limb onset with tremor may be a clue.
• Weakness out of proportion to wasting (suggests demyelination, not pure axonopathy).
• Palpably thickened nerves can sometimes be felt.
• Generalised, symmetric weakness distinguishes it from multifocal motor neuropathies.

🧪 Investigations

• Bloods: FBC, U&E, B12, ANA, HIV/HCV/HBV, paraprotein screen (SPEP).
• CSF: Classic finding = albuminocytologic dissociation (↑ protein >1g/L with normal WCC) 💧.
• Nerve Conduction Studies: Slow conduction, prolonged distal latencies, conduction block = demyelination 🚦.
• Biopsy: Shows segmental demyelination, remyelination & onion-bulb changes.

🔍 Differential Diagnosis

• GBS (AIDP – acute form).
• Critical illness neuropathy (ICU patients).
• Drug-induced neuropathy (e.g. Amiodarone).
• Paraproteinemic neuropathy (e.g. MGUS, Myeloma).

💊 Management

• First-line: Steroids (e.g. Prednisolone 60 mg daily for 4–6 weeks) – taper guided by response.
• IVIG: 0.4 g/kg/day × 5 days – useful especially in relapsing disease or steroid intolerance.
• Plasma Exchange: Removes pathogenic antibodies – for severe or refractory cases.
• Steroid-sparing agents: Azathioprine, Methotrexate, or Mycophenolate may be added.
• Refractory / Paraprotein-related: Consider Rituximab, and liaise with haematology.
• Rehabilitation: Physio + OT crucial for recovery, preventing contractures and improving function 🏃.

🧾 Exam Pearls

✅ Time course distinguishes CIDP (>8 weeks) from GBS (<4 weeks).
✅ Albuminocytologic dissociation in CSF is a classic finding.
✅ Treatable neuropathy → always consider early immunotherapy.
✅ Prognosis: Many improve with treatment, but relapses are common.

Cases — Chronic Inflammatory Demyelinating Polyneuropathy (CIDP)

• Case 1 — Progressive Weakness: A 48-year-old man presents with 4 months of progressive difficulty climbing stairs and frequent tripping. Exam: symmetrical weakness in proximal and distal leg muscles, reduced reflexes, impaired vibration sense in feet. Diagnosis: CIDP with progressive motor and sensory deficits. Management: Corticosteroids, IV immunoglobulin, or plasma exchange; physiotherapy for rehabilitation.
• Case 2 — Relapsing-Remitting Course: A 35-year-old woman reports recurrent episodes of limb weakness and numbness over 2 years, each lasting weeks and partially recovering. Exam: distal weakness, absent ankle jerks, glove-and-stocking sensory loss. Nerve conduction: demyelinating pattern. Diagnosis: Relapsing-remitting CIDP. Management: Immunomodulatory therapy (IVIG, steroids); maintenance immunosuppressants if frequent relapses.
• Case 3 — Severe Disability with Cranial Nerve Involvement: A 55-year-old man develops progressive limb weakness, bilateral facial weakness, and dysphagia over 8 months. Wheelchair-bound. CSF shows albuminocytologic dissociation (high protein, normal cells). Diagnosis: Severe CIDP with cranial nerve involvement. Management: Escalated therapy: plasma exchange or IVIG, long-term immunosuppressants (azathioprine, rituximab in refractory cases), multidisciplinary support.

Teaching Commentary 🧠

CIDP is a chronic, immune-mediated demyelinating neuropathy and the chronic counterpart of Guillain–Barré syndrome. It presents with progressive (≥8 weeks) or relapsing symmetrical weakness, sensory loss, and reduced reflexes. Key investigations: - Nerve conduction: demyelination (slowed conduction velocity, conduction block). - CSF: high protein, normal cell count. - MRI may show nerve root enhancement. Treatment is with steroids, IVIG, or plasma exchange, and long-term immunosuppression if refractory. Prognosis is variable, but many improve significantly with immunotherapy.