Lambert-Eaton myasthenic syndrome is characterized by muscle weakness, hyporeflexia, and autonomic dysfunction, which result from impaired release of acetylcholine from cholinergic nerve terminals. It is frequently associated with cancer, it is autoimmune-mediated, and treatment has been unsatisfactory. 3,4-Diaminopyridine enhances the release of acetylcholine. In this prospective, double-blind, placebo-controlled crossover study of 12 patients with Lambert-Eaton myasthenic syndrome (7 of whom had cancer), 3,4-diaminopyridine in doses up to 100 mg per day was effective in treating both the motor and the autonomic deficits of the syndrome. Muscle strength increased from an average of 70 percent of normal to 81 percent of normal in the upper extremities, and from 45 to 65 percent of normal in the lower extremities. The amplitudes of compound-muscle-action potentials nearly doubled, increasing from an average of 2.9 mV to 5.0 mV in the arm and from 1.6 mV to 3.1 mV in the leg. Autonomic symptoms were relieved. One patient had a seizure after 10 months of treatment, but other side effects from the drug were minimal and dose-related. We conclude that 3,4-diaminopyridine, either alone or in conjunction with other therapies, may be useful in the treatment of Lambert-Eaton myasthenic syndrome.
KM McEvoy ,AJ Windebank , Daube JR,PA Low
Source Information
Department of Neurology, Mayo Clinic, Rochester, MN 55905.
This article has been cited by other articles:
de Beukelaar, J. W., Smitt, P. A. S.
(2006). Managing paraneoplastic neurological disorders.. The Oncologist
11: 292-305
[Abstract][Full Text]
Harper, C. M., Fukodome, T., Engel, A. G.
(2003). Treatment of slow-channel congenital myasthenic syndrome with fluoxetine. Neurology
60: 1710-1713
[Abstract][Full Text]
Tsao, C.-Y., Mendell, J. R., Friemer, M. L., Kissel, J. T.
(2002). Lambert-Eaton Myasthenic Syndrome in Children. J Child Neurol
17: 74-76
[Abstract]
Noseworthy, J. H., O'Brien, P. C., Weinshenker, B. G., Weis, J. A., Petterson, T. M., Erickson, B. J., Windebank, A. J., Whisnant, J. P., Stolp-Smith, K. A., Harper, C. M. Jr., Low, P. A., Romme, L. J., Johnson, M., An, K.-N., Rodriguez, M.
(2000). IV immunoglobulin does not reverse established weakness in MS: A double-blind, placebo-controlled trial. Neurology
55: 1135-1143
[Abstract][Full Text]
Sanders, D. B., Massey, J. M., Sanders, L. L., Edwards, L. J.
(2000). A randomized trial of 3,4-diaminopyridine in Lambert-Eaton myasthenic syndrome. Neurology
54: 603-603
[Abstract][Full Text]
Seneviratne, U., de Silva, R.
(1999). Classic diseases revisited: Lambert-Eaton myasthenic syndrome. Postgrad. Med. J.
75: 516-520
[Abstract][Full Text]
Suarez, G. A., Opfer-Gehrking, T. L., Offord, K. P., Atkinson, E. J., O'Brien, P. C., Low, P. A.
(1999). The Autonomic Symptom Profile: A new instrument to assess autonomic symptoms. Neurology
52: 523-523
[Abstract][Full Text]
van LUNTEREN, E., MOYER, M.
(1998). Electrophysiologic and Inotropic Effects of K+-Channel Blockade in Aged Diaphragm. Am. J. Respir. Crit. Care Med.
158: 820-826
[Abstract][Full Text]
Maddison, P., Newsom-Davis, J., Mills, K. R
(1998). Distribution of electrophysiological abnormality in Lambert-Eaton myasthenic syndrome. J. Neurol. Neurosurg. Psychiatry
65: 213-217
[Abstract][Full Text]
Eder, J. P., Nguyen, P. L.
(1997). Case 21-1997- A 67-Year-Old Woman with a Progressive Movement Disorder and a Left-Upper-Quadrant Mass. NEJM
337: 115-122
[Full Text]
Pinter, M. J., Waldeck, R. F., Cope, T. C., Cork, L. C.
(1997). Effects of 4-Aminopyridine on Muscle and Motor Unit Force in Canine Motor Neuron Disease. J. Neurosci.
17: 4500-4507
[Abstract][Full Text]
Van Lunteren, E., Moyer, M.
(1996). Effects of DAP on diaphragm force and fatigue, including fatigue due to neurotransmission failure. J. Appl. Physiol.
81: 2214-2220
[Abstract][Full Text]
Weinberg, D., Mark, E. J.
(1994). Case 32-1994- A 61-Year-Old Man with Muscular Weakness. NEJM
331: 528-535
[Full Text]
Erlington, G.
(1992). Review paper: The Lambert-Eaton myasthenic syndrome. Palliat Med
6: 9-17
[Abstract]
Previous
