Repetitive nerve stimulation studies in the Lambert-Eaton myasthenic syndrome
- PMID: 8065402
- DOI: 10.1002/mus.880170906
Repetitive nerve stimulation studies in the Lambert-Eaton myasthenic syndrome
Abstract
We compared changes in amplitude and area of surface recorded compound motor action potentials (CMAPs) during 20-Hz repetitive nerve stimulation and after maximum voluntary contraction in patients with the Lambert-Eaton myasthenic syndrome (LEMS), myasthenia gravis (MG), and normal controls. There was greater potentiation of CMAP amplitude after voluntary contraction than during 20-Hz stimulation in 10 of 14 LEMS patients; CMAP area increased more after exercise than during 20-Hz stimulation in all LEMS patients. Although abnormal potentiation of CMAP area and amplitude was seen in equal numbers of LEMS patients, more LEMS patients demonstrated a greater than 100% potentiation of CMAP area than of CMAP amplitude. We conclude that maximum voluntary contraction is preferable to brief 20-Hz RNS to demonstrate potentiation in LEMS because it is at least as sensitive and is less painful. Measurement of CMAP area in LEMS patients is not better than measuring the change in CMAP amplitude in demonstrating abnormal potentiation. Testing of a single hand muscle for potentiation in LEMS does not demonstrate abnormal potentiation in all LEMS patients.
Comment in
-
Clinical correlates in the deep tendon reflexes of the electrophysiology in the Lambert-Eaton myasthenic syndrome and myasthenia gravis.Muscle Nerve. 1995 Aug;18(8):920-1. doi: 10.1002/mus.880180821. Muscle Nerve. 1995. PMID: 7503883 No abstract available.
Similar articles
-
Stimulated single-fiber electromyography in Lambert-Eaton myasthenic syndrome.Muscle Nerve. 1991 Dec;14(12):1227-30. doi: 10.1002/mus.880141215. Muscle Nerve. 1991. PMID: 1662773
-
Electrophysiological diagnostic criteria of Lambert-Eaton myasthenic syndrome.Muscle Nerve. 2005 Oct;32(4):515-20. doi: 10.1002/mus.20389. Muscle Nerve. 2005. PMID: 16003742
-
Decrement pattern in Lambert-Eaton myasthenic syndrome is different from myasthenia gravis.Neuromuscul Disord. 2006 Jul;16(7):454-8. doi: 10.1016/j.nmd.2006.05.009. Epub 2006 Jun 30. Neuromuscul Disord. 2006. PMID: 16806929
-
Lambert-Eaton myasthenic syndrome (LEMS) in association with lymphoproliferative disorders.Muscle Nerve. 1995 Jul;18(7):715-9. doi: 10.1002/mus.880180707. Muscle Nerve. 1995. PMID: 7783761 Review.
-
[Lambert-Eaton syndrome: clinical and electrophysiological study of 18 cases associated with lung cancer].Rev Neurol (Paris). 1992;148(6-7):513-9. Rev Neurol (Paris). 1992. PMID: 1448671 Review. French.
Cited by
-
Therapeutic Outcomes and Electrophysiological Biomarkers in Anti-Myelin-Associated Glycoprotein Neuropathy: A Multicenter Cohort Study in South Korea.J Clin Neurol. 2024 Jan;20(1):50-58. doi: 10.3988/jcn.2023.0127. J Clin Neurol. 2024. PMID: 38179632 Free PMC article.
-
A Functional Human-on-a-Chip Autoimmune Disease Model of Myasthenia Gravis for Development of Therapeutics.Front Cell Dev Biol. 2021 Nov 22;9:745897. doi: 10.3389/fcell.2021.745897. eCollection 2021. Front Cell Dev Biol. 2021. PMID: 34881241 Free PMC article.
-
Bioengineered optogenetic model of human neuromuscular junction.Biomaterials. 2021 Sep;276:121033. doi: 10.1016/j.biomaterials.2021.121033. Epub 2021 Jul 30. Biomaterials. 2021. PMID: 34403849 Free PMC article.
-
Lowering the cutoff value for increment increases the sensitivity for the diagnosis of Lambert-Eaton myasthenic syndrome.Muscle Nerve. 2020 Jul;62(1):111-114. doi: 10.1002/mus.26885. Epub 2020 Apr 22. Muscle Nerve. 2020. PMID: 32291768 Free PMC article.
-
Quantification of human neuromuscular function through optogenetics.Theranostics. 2019 Jan 31;9(5):1232-1246. doi: 10.7150/thno.25735. eCollection 2019. Theranostics. 2019. PMID: 30867827 Free PMC article.
Publication types
MeSH terms
LinkOut - more resources
Full Text Sources
Medical
