Chronic inflammatory demyelinating polyneuropathy with hypertrophic nerves.

Area of Science:

• Neurology
• Clinical Neuroscience
• Peripheral Nerve Disorders

Background:

• Chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare autoimmune disorder affecting peripheral nerves.
• Nerve hypertrophy, while uncommon, can occur in CIDP, presenting unique diagnostic and clinical challenges.

Observation:

• A case of CIDP with massive peripheral nerve and cranial nerve enlargement (up to 10-fold normal) is presented with detailed imaging and electrodiagnostic findings.
• Clinical presentation included insidious onset, gait ataxia, and sensory symptoms, with high cerebrospinal fluid protein levels.
• Imaging revealed hypertrophic cranial nerves and spinal roots with gadolinium enhancement, alongside significant peripheral nerve swelling.

Findings:

• Electrodiagnostic studies demonstrated markedly slowed nerve conduction velocities, conduction blocks, and increased distal compound muscle action potential duration.
• Despite severe nerve hypertrophy, clinical symptoms were relatively mild, indicating a potential discrepancy between structural changes and functional deficits.
• Genetic testing for common neuropathy-related mutations was negative, suggesting a distinct underlying mechanism.

Implications:

• This case highlights the variable presentation of CIDP and the diagnostic utility of advanced imaging techniques like nerve ultrasound and MRI.
• The findings suggest that nerve enlargement in CIDP may correlate with disease duration and electrophysiological parameters but not necessarily with clinical severity.
• Understanding the relationship between nerve hypertrophy and clinical symptoms in CIDP can refine diagnostic approaches and treatment strategies for this complex neuropathy.