Guillain–Barré syndrome

The term Guillain–Barré syndrome (GBS), the most frequent cause of acute paralytic neuropathy, covers a number of recognisably distinct variants. The exact cause of GBS is unknown, but 50–70% of cases appear 1–2 weeks after a respiratory or gastrointestinal infection, or another immune stimulus that induces an aberrant autoimmune response targeting peripheral nerves and their spinal roots. The interplay between the microbial and host factors that dictate whether and how the immune response shifts towards autoreactivity is still unclear, and nothing is known about the genetic and environmental factors that affect an individual's susceptibility to the disease. All patients with GBS need meticulous monitoring, and can benefit from supportive care and the early start of specific treatment. This review summarises the clinical features and diagnostic criteria of GBS and proposes an algorithm for its management. An analysis of the literature showed that, about one century after it was first described, new information concerning its etiopathogenesis has allowed the development of new treatment strategies that should be started immediately after diagnosis; however, the available therapies are not sufficient in many patients, especially in the presence of the acute inflammatory demyelinating polyneuropathy. New post-infectious forms, such as those caused by Zika virus and enterovirus D68, need to be carefully analysed and, in order to improve patient outcomes, research should continue to aim at identifying new biomarkers of disease severity and better means of avoiding axonal injury.