Neurophysiology of Neuromuscular Transmission and Its Disorders
Despite several antibody tests being available for the assessment of disorders of neuromuscular transmission, electrophysiological testing of the neuromuscular junction remains a very important part of clinical practice. The neuromuscular junction is a complex structure and an understanding of its anatomy and physiology can assist in better understanding the value of electrodiagnostic testing. The most common disorders include myasthenia gravis, Lambert-Eaton myasthenic syndrome, and botulism, and are usually readily identified using several electrophysiological techniques including slow (2-3 Hz) and fast (20- to 50-Hz stimulation). Single-fiber needle EMG remains an additional powerful and sensitive test for patients with disorders that are more mild, in whom repetitive stimulation testing is negative or indeterminate.
Key WordsBotulism Lambert-Eaton myasthenic syndrome myasthenia gravis neuromuscular junction repetitive nerve stimulation
Unable to display preview. Download preview PDF.
- AAEM Professional Practice Committee, Chiou-Tan FY, Gilchrist JM, Tim RW. Practice parameter for repetitive nerve stimulation and single fiber electromyographic evaluation of adult patients with suspected myasthenia gravis or Lambert-Eaton myasthenic syndrome: summary statement. Muscle Nerve, 2001.Google Scholar
- Engel AG, ed. Myasthenia Gravis and Myasthenic Disorders. Oxford University Press, New York, NY, 1999.Google Scholar
- Gilchrist JM. Myasthenia gravis. In: Current Diagnosis in Neurology (Feldmann E, ed.). Mosby, St. Louis, MO, 1994, pp. 350–352.Google Scholar
- Stalberg E, Trontelj JV. Single Fiber Electromyography. Studies in Healthy and Disease Muscle. 2nd Ed. Raven Press, New York, NY, 1994.Google Scholar