What is the treatment approach for acquired hypertrophic neuropathy?

Acquired Hypertrophic Neuropathy: Treatment Approach

For acquired hypertrophic neuropathy, immunosuppressive therapy with corticosteroids and/or intravenous immunoglobulin (IVIG) is the primary treatment, with surgical decompression reserved for patients with compressive radiculopathy who fail medical management or have severe mechanical compression. 1, 2

Diagnostic Confirmation Required

Before initiating treatment, confirm the acquired inflammatory etiology through:

• Electrophysiological studies showing demyelinating features with markedly slowed conduction velocities (often <10 m/s) and dispersed, polyphasic compound muscle action potentials 2, 3
• Nerve biopsy demonstrating characteristic "onion bulb" formation (S-100-positive Schwann cell proliferation) consistent with chronic inflammatory demyelinating polyneuropathy (CIDP) 2
• MRI imaging revealing nerve enlargement and thickening to distinguish from hereditary forms 1, 2

Medical Management: First-Line Approach

Immunosuppressive Therapy

Corticosteroids are the initial treatment of choice, with dramatic responses documented even in chronic cases:

• Oral prednisone initiated at immunosuppressive doses (typically 1 mg/kg/day) 1, 3
• Treatment duration of at least 2 months before assessing response, with some patients requiring long-term maintenance therapy 1, 3
• Clinical improvement includes restoration of muscle power, normalization of enlarged nerves, and electrophysiological recovery 3

Alternative Immunotherapy

Intravenous immunoglobulin (IVIG) is recommended when:

• Corticosteroids are contraindicated or poorly tolerated 1
• Combined with steroids for severe or refractory cases 1
• Standard CIDP dosing protocols apply (typically 2 g/kg divided over 2-5 days, then maintenance dosing) 1

Surgical Management: Selective Indication

Decompressive laminectomy with dural expansion is indicated specifically for:

• Symptomatic spinal canal stenosis from cauda equina nerve root enlargement causing mechanical compression 1, 2
• Failed medical management with persistent radicular pain, progressive weakness, or sensory loss 2
• Severe compressive symptoms including inability to ambulate independently 1

Surgical Technique Considerations

• Perform multilevel decompressive laminectomy (typically L1-L5) with continuous somatosensory evoked potential and electromyographic monitoring 2
• Dural expansion with patch graft to accommodate enlarged nerve roots 2
• Obtain nerve biopsy during surgery for definitive pathological diagnosis 1, 2

Critical Point on Combined Therapy

Surgery alone is insufficient—optimal outcomes require combining decompression with immunosuppressive therapy:

• One pediatric case showed initial improvement with surgery but achieved normal ambulation only after adding IVIG and long-term steroids postoperatively 1
• Medical management addresses the underlying inflammatory pathology while surgery relieves mechanical compression 1, 2

Treatment Algorithm

1. Confirm diagnosis through electrodiagnostics, imaging, and nerve biopsy 2
2. Initiate corticosteroids as first-line therapy for 2+ months 3
3. Add or substitute IVIG if inadequate response or steroid intolerance 1
4. Consider surgical decompression only if compressive radiculopathy persists despite medical therapy 2
5. Continue long-term immunosuppression even after surgery to prevent relapse 1

Common Pitfalls to Avoid

• Do not delay immunotherapy while pursuing extensive diagnostic workup—early treatment prevents irreversible axonal loss 3
• Do not perform surgery without confirming inflammatory etiology—hereditary hypertrophic neuropathies do not respond to immunotherapy and have different surgical considerations 2, 4
• Do not discontinue immunosuppression prematurely after surgical improvement—the inflammatory process requires ongoing treatment 1
• Do not confuse with localized hypertrophic neuropathy affecting single peripheral nerves (e.g., median nerve), which may require different surgical approaches 5