Inflammation and neuropathic attacks in hereditary brachial plexus neuropathy

Area of Science:

• Neurology
• Immunology
• Genetics

Background:

• Hereditary brachial plexus neuropathy (HBPN) is an autosomal dominant disorder.
• It causes attacks of pain, weakness, atrophy, and sensory changes in the shoulder and upper limb.

Purpose of the Study:

• To investigate the role of mechanical, infectious, and inflammatory factors in HBPN attacks.
• To explore potential therapeutic strategies for managing HBPN.

Main Methods:

• Evaluated four patients from separate HBPN kindreds.
• Obtained upper extremity nerve biopsies during attacks.
• Performed in situ hybridization for viruses and genetic testing for hereditary neuropathy with liability to pressure palsies (HNPP).
• Administered intravenous methylprednisolone to two patients and monitored outcomes.
• Followed one patient prospectively through pregnancy and postpartum.

Main Results:

• Nerve biopsies revealed significant perivascular inflammatory infiltrates and vessel wall disruption in two patients.
• Viral testing was negative, and no tomaculous nerve changes were observed.
• Methylprednisolone temporarily improved symptoms, primarily pain, but attacks recurred upon dose tapering.
• Cesarean delivery did not prevent a postpartum attack.

Conclusions:

• Immune-mediated inflammation is likely a key factor in HBPN attacks.
• Immunomodulatory therapies may offer a way to prevent or reduce attack severity.
• Genes involved in immune regulation are potential candidates for causing HBPN.