Management of Hereditary Neuropathy with Liability to Pressure Palsies (HNPP)
The management of HNPP should focus primarily on preventive measures to avoid nerve compression and trauma, with consideration of corticosteroid therapy for protracted recovery cases.
Clinical Presentation and Diagnosis
- HNPP is characterized by recurrent sensory and motor neuropathies in individual nerves, typically starting in adolescence or young adulthood 1
- Diagnosis involves:
- Clinical assessment of recurrent focal neuropathies
- Electrodiagnostic testing showing focal conduction abnormalities at entrapment sites
- Genetic testing for deletion of chromosome 17p11.2-p12 region including the PMP-22 gene
- Nerve biopsy (if needed) showing sausage-like swellings (tomacula) of myelin sheaths
Preventive Management
- Avoid activities that cause prolonged nerve compression:
- Repetitive movements
- Prolonged positioning with pressure on vulnerable nerves
- Hyperextension of joints (particularly wrists) 2
- Use protective padding at common compression sites:
- Elbow pads to protect ulnar nerve
- Knee pads to protect peroneal nerve
- Educate patients about avoiding:
- Crossing legs for extended periods
- Leaning on elbows
- Repetitive movements that could compress nerves
Acute Management of Pressure Palsies
- Rest and protection of the affected limb/nerve
- Corticosteroid therapy for cases with protracted or incomplete recovery:
- Consider a trial of corticosteroids for patients with symptoms persisting beyond 5 months
- This approach has shown considerable improvement leading to near-complete recovery of muscle power in some cases 3
- Physical therapy to maintain range of motion and prevent contractures
- Occupational therapy for adaptive strategies and assistive devices
Special Considerations
Anesthetic Management
- Increased risk of neural compressive injury during surgical procedures
- Anesthesiologists should be informed of the diagnosis
- Extra care with positioning during surgery and labor
- Consider alternative approaches to regional anesthesia 4
Brachial Plexus Involvement
- Some families may present with recurrent brachial plexopathy as the only symptom 5
- Requires careful differentiation from hereditary neuralgic amyotrophy
Unusual Presentations
- HNPP can present with multiple simultaneous compression neuropathies
- Bilateral involvement is possible, particularly with activities requiring specific positioning 2
Monitoring and Follow-up
- Regular neurological assessments to monitor progression
- Electrodiagnostic studies to assess recovery and detect new compression sites
- Genetic counseling for family members
Management of Neuropathic Pain
- First-line medications for neuropathic pain:
- Gabapentin
- Pregabalin
- Duloxetine
- Avoid opioids for long-term management due to potential adverse effects
HNPP is often underdiagnosed or misdiagnosed due to the heterogeneity of clinical and electrophysiological presentations 1. A high index of suspicion is needed, particularly in patients with recurrent, painless mononeuropathies at typical compression sites with family history of similar symptoms.