NEUROMUSCULAR DISEASE | Peripheral Nerves

Injury to and/or dysfunction of peripheral nerves may arise from autoimmune processes that target the Schwann cell, myelin, and/or axon. Because of the dramatic and potentially life-threatening involvement of the respiratory system, the Guillain–Barre syndrome (GBS), the prototypic immune-mediated peripheral neuropathy, will be the focus of this article. Required criteria for its diagnosis include progressive weakness of two or more limbs, hyporeflexia or areflexia, and progression for no more than 4 weeks. At least 70% of patients with GBS have a history of a preceding infection and case–control studies have demonstrated significant associations with a number of pathogens, particularly Campylobacter jejuni. The pathogenesis of GBS is currently viewed as an organ-specific, immune-mediated disorder arising from synergistic interactions of humoral and cell-mediated immune responses to as yet incompletely characterized peripheral nerve antigens. The mainstay of treatment continues to be supportive measures and intensive care, but several control clinical trials have demonstrated that both plasma exchange and intravenous immunoglobulin shorten the time to recovery when used in the early stages of the disease. Overall, the prognosis for recovery is favorable, with mortality below 5% and the majority of patients experiencing little or no disability.