Makindo Medical Notes

Related Subjects: |Neurological History taking |Motor Neuron Disease (MND-ALS) |Miller-Fisher syndrome |Guillain Barre Syndrome |Multifocal Motor Neuropathy with Conduction block | Multiple Sclerosis (MS) Demyelination | Transverse myelitis | Acute Disseminated Encephalomyelitis | Progressive Multifocal Leukoencephalopathy (PML) | Inclusion Body Myositis |Cervical spondylosis |Anterior Spinal Cord syndrome |Central Spinal Cord syndrome |Brown-Sequard Spinal Cord syndrome |Spinal Cord Compression |Spinal Cord Haematoma |Spinal Cord Infarction

Note: Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) is a treatable form of Guillain-Barré Syndrome (GBS) that responds to steroids.

About

• Definition: Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) is an immune-mediated neuropathy characterized by progressive or relapsing weakness and sensory dysfunction.
• Onset: Typically subacute, developing over weeks, with progressive weakness and areflexia (loss of reflexes).

Aetiology

• Immune-mediated demyelination: The immune system attacks the myelin sheath of peripheral nerves, leading to demyelination and impaired nerve function.

Associations

• Infections: HIV, HBV, HCV.
• Hematologic: Monoclonal Gammopathy associated CIDP.
• Autoimmune conditions: Multiple Sclerosis (MS), Systemic Lupus Erythematosus (SLE), Diabetes.
• Other associations: Inflammatory Bowel Disease, Pregnancy.

Clinical Presentation

• Progressive weakness and sensory loss: Symptoms typically start with tingling in hands and feet and progress to difficulty rising from a chair.
• Weakness pattern: Symmetrical distal and proximal weakness, often with postural tremor.
• Cranial nerve involvement: Rare, but may include facial weakness or third cranial nerve palsy.
• Sensory loss: Distal sensory loss may be observed.
• Areflexia: Tendon reflexes are often lost, consistent with lower motor neuron (LMN) signs.

Helpful Pointers

• Upper limb onset: Symptoms may start in the arms with associated postural tremor.
• Weakness out of proportion to wasting: Notable strength loss without significant muscle wasting.
• Thickened nerves: Enlarged peripheral nerves may be palpable.
• Generalized weakness: Widespread muscle weakness is common.

Investigations

• Blood tests: Full blood count (FBC), Urea & Electrolytes (U&E), Vitamin B12, Antinuclear Antibodies (ANA), HCV, and HIV testing.
• Plasma protein electrophoresis: To detect monoclonal proteins associated with CIDP.
• CSF analysis: Elevated protein (> 1g/L) with normal white cell count (WCC < 10) and glucose levels. Oligoclonal bands may be present.
• Nerve conduction studies: Show demyelination with slowed conduction and conduction block, often starting proximally.
• Nerve biopsy: May be performed in selected cases to confirm diagnosis.

Differential Diagnosis

• Acute Inflammatory Demyelinating Polyneuropathy (AIDP): The classic form of Guillain-Barré Syndrome (GBS).
• Critical illness polyneuropathy: Weakness seen in patients in intensive care unit (ICU) settings.
• Drug-induced neuropathy: For example, secondary to Amiodarone use.
• Paraproteinemia-related neuropathy: Such as in myeloma or Monoclonal Gammopathy of Undetermined Significance (MGUS).

Management

• First-line treatment: High-dose steroids (e.g., Prednisolone 60 mg once daily for 4-6 weeks), with possible addition of a steroid-sparing agent (e.g., Azathioprine or Methotrexate).
• Immunoglobulin therapy: High-dose intravenous immunoglobulins (IVIG) at 0.4g/kg/day for 5 days.
• Plasma exchange: Considered if there is no improvement with steroids or IVIG.
• Paraprotein-associated CIDP: If CIDP is associated with a paraprotein, workup for myeloma should be performed. Steroid and plasma exchange response is typically poor, but Rituximab may be effective. Collaboration with hematologists is advised.
• Rehabilitation: Ongoing physical and occupational therapy is essential for recovery over weeks to months.