Inflammation and neuropathic attacks in hereditary brachial plexus neuropathy
- 1Peripheral Neuropathy Research Center, Mayo Clinic, Rochester, Minnesota, USA
- 2Geisinger Medical Center, Department of Neurology, North Academy Avenue, Danville, Pennsylvania, USA
- 3Department of Neurology, Lahey Clinic, Mall Road, Burlington, Massachusetts, USA
- 4Department of Neurology, Mayo Clinic
- Correspondence to: Dr Christopher J Klein, Mayo Clinic, 200 First Street SW, Rochester, Minnesota 55905, USA;
- Received 3 December 2001
- Accepted 4 March 2002
- Revised 14 February 2002
Objective: To study the role of mechanical, infectious, and inflammatory factors inducing neuropathic attacks in hereditary brachial plexus neuropathy (HBPN), an autosomal dominant disorder characterised by attacks of pain and weakness, atrophy, and sensory alterations of the shoulder girdle and upper limb muscles.
Methods: Four patients from separate kindreds with HBPN were evaluated. Upper extremity nerve biopsies were obtained during attacks from a person of each kindred. In situ hybridisation for common viruses in nerve tissue and genetic testing for a hereditary tendency to pressure palsies (HNPP; tomaculous neuropathy) were undertaken. Two patients treated with intravenous methyl prednisolone had serial clinical and electrophysiological examinations. One patient was followed prospectively through pregnancy and during the development of a stereotypic attack after elective caesarean delivery.
Results: Upper extremity nerve biopsies in two patients showed prominent perivascular inflammatory infiltrates with vessel wall disruption. Nerve in situ hybridisation for viruses was negative. There were no tomaculous nerve changes. In two patients intravenous methyl prednisolone ameliorated symptoms (largely pain), but with tapering of steroid dose, signs and symptoms worsened. Elective caesarean delivery did not prevent a typical postpartum attack.
Conclusions: Inflammation, probably immune, appears pathogenic for some if not all attacks of HBPN. Immune modulation may be useful in preventing or reducing the neuropathic attacks, although controlled trials are needed to establish efficacy, as correction of the mutant gene is still not possible. The genes involved in immune regulation may be candidates for causing HBPN disorders.
- HBPN, hereditary brachial plexus neuropathy
- HMSN, hereditary motor and sensory neuropathy
- HNPP, hereditary neuropathy with pressure palsies
- NIS, Neuropathy Impairment Score
- NSC, Neuropathy Symptoms and Change score