Acute and chronic immune neuropathies and radiculopathies

Immune-mediated neuropathies constitute acute and chronic disorders, the prototypes of which are Guillain-Barré syndrome (GBS) and chronic inflammatory/immune demyelinating polyradiculoneuropathy (CIDP), respectively. The most common variants of GBS are acute inflammatory/immune demyelinating polyradiculoneuropathy (AIDP) and acute motor axonal neuropathy (AMAN), but less common variants exist. Cell-mediated and antibody-mediated mechanisms are suspected in the pathophysiology of GBS, which is often precipitated by an antecedent event. GBS is characterized by symmetric weakness, areflexia, sensory symptoms, and frequent autonomic features. The clinical course is monophasic with spontaneous recovery, but residual deficits are common. Immunomodulatory therapy with intravenous immunoglobulin (IVIg) and plasma exchange (PLEX) hastens recovery and likely improves clinical outcomes. CIDP also has several variants and is often regarded as the chronic counterpart to GBS. As with GBS, the pathophysiology of this disorder has yet to be fully characterized, and both cell-mediated and antibody-mediated mechanisms are thought to be instrumental. Accurate diagnosis is paramount and necessitates evidence of a primary demyelinating polyneuropathy. Several important mimics of CIDP are demyelinating hereditary motor sensory neuropathy (HMSN); IgM-associated neuropathy; and polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, and skin changes (POEMS) syndrome. The first-line maintenance therapies for CIDP are corticosteroids and IVIg; however, there is growing evidence that rituximab has a role in certain subpopulations of CIDP. With appropriate treatment, many patients with CIDP may achieve remission or cure.