Chapter 14 Immune mediated peripheral neuropathies

Abstract

The most recent progress in understanding the pathogenesis of immune mediated neuropathies has been achieved by advances in the fields of neuroimmunology and molecular biology. The description of experimental allergic neuritis is the first example of the probable connection between immunological events and peripheral neuropathy. These disorders can be divided into two groups: those associated with underlying autoimmune system disease, such as vasculitis, systemic lupus erythematosus, human immunodeficiency virus (HIV), and others, seemingly arising in the peripheral nervous system. Interactions of the immune system, with peripheral nerves, are implicated in the pathogenesis of several neuropathic syndromes. Integrity impairment of the blood–nerve barrier that sequesters the endoneural compartment from the blood constituents is an initial step in the pathogenesis of these disorders, facilitating the trafficking of lymphocytes and inflammatory mediators into the endoneural compartment. All patients with peripheral neuropathies should have thorough electrodiagnostic studies as a prelude to further investigation. Usually, the diagnosis can be made by clinical and electrodiagnostic testing. The classification of these disorders includes only those acquired neuropathies, in which demyelination is the most significant feature, and is thought to occur as a primary event. Within this frame, there may be included, as first group, acute forms of neuropathy, such as Guillain–Barré syndrome (GBS) and its variants, and as second group chronic forms, such as chronic idiopathic demyelinating polyneuropathy (CIDP) with or without monoclonal gammopathy and multifocal motor neuropathy (MMN) as well as other neuropathies, associated with anti-ganglioside antibodies. However, despite the recent advances, treatment problems remain and the disease mechanisms are only partially understood. This chapter discusses the experience gathered in the chronic forms of these neuropathies.