Autoimmune neuromyotonia. Issue 5 (19th October 2022)

• Record Type: Journal Article
• Authors: Comperat, Louis; Pegat, Antoine; Honnorat, Jérôme; Joubert, Bastien
• Is Part Of: Current opinion in neurology. Volume 35:Issue 5(2022)
• Page Start: 597
• Page End: 603
• Publication Date: 2022-10-19
• Subjects: contactin-associated protein-like 2 -- cramp-fasciculation syndrome -- Isaacs syndrome -- Morvan syndrome -- neuromyotonia; Neurology -- Periodicals; Nervous system -- Diseases -- Periodicals; 616.805
• DOI: 10.1097/WCO.0000000000001104
• Languages: English
• ISSNs: 1473-6551

Abstract

Abstract : Purpose of review: Autoimmune neuromyotonia encompasses a group of rare immune-mediated neurological disorders frequently associated with anti-contactin-associated protein-like 2 (CASPR2) antibodies and featuring clinical and electrical signs of peripheral nerve hyperexcitability (PNH). We aim to summarize the current knowledge on immune-mediated neuromyotonia, focusing on clinical presentations, pathophysiology, and management. Recent findings: Neuromyotonia is a major feature of several autoimmune neurological syndromes characterized by PNH with or without central neurological system involvement. Experimental and clinical evidence suggest that anti-CASPR2 antibodies are directly pathogenic in autoimmune neuromyotonia patients. Summary: Neuromyotonia, a form of PNH, is a major feature in several syndromes associated with anti-CASPR2 antibodies, including cramp-fasciculation syndrome, Isaacs syndrome, Morvan syndrome, and autoimmune limbic encephalitis. Diagnosis relies on the identification of motor, sensory, and autonomic signs of PNH along with other neurological symptoms, anti-CASPR2 antibody-positivity, and of characteristic electroneuromyographic abnormalities. Paraneoplastic associations with thymoma are possible, especially in Morvan syndrome. Patients usually respond to immune-active treatments, including steroids, intravenous immunoglobulins, plasma exchanges, and rituximab.