Myasthenic syndromes

D-penicillamine a well-recognized complication of the use of D-penicillamine is a myasthenic syndrome. Most reported cases of myasthenic syndrome are women and the ocular muscles appear to be particularly commonly affected at early stages of the abnormality. The onset of the myasthenic syndrome can range between a few months and many years, and is not always reversible. There is a clear immunological basis to this problem, because it is associated with raised anti-acetylcholine receptor antibodies circulating in the serum. Antibody levels fall when the drug is withdrawn, and this, in turn, is associated with clinical improvement. How the... 

Paraneoplastic sensory neuropathy Lambert-Eaton myasthenic syndrome Neuromyotonia (Isaacs syndrome)... 

Pinto, A., Iwasa, K., Newland, C., Newsom-Davis, J. and Lang, B. The action of Lambert-Eaton myasthenic syndrome immunoglobulin G on cloned human voltage-gated calcium channels. Muscle Nerve 25 715-724, 2002. 

Congenital myasthenic syndromes impair the operation of the acetylcholine receptor 719... 

Engel, A. G., Ohno, K. and Sine, S. M. Congenital myasthenic syndromes a diverse array of molecular targets. /. Neurocytol. 32 1017-1037,2003. 

Lang, B. and Newsom-Davis, J. Immunopathology of the Lambert-Eaton myasthenic syndrome. Springer Semin. Immunopathol. 17 3-15,1995. 

LEMS Lambert-Eaton myasthenic syndrome NAADP nicotinic acid-adenine dinucleotide phosphate... 

Hepatotoxicity Penicillamine has been associated with a mild elevation of hepatic enzymes that usually returns to normal even with continuation of the drug. Autoimmune syndromes Autoimmune syndromes that may be caused by penicillamine include polymyositis, diffuse alveolitis and dermatomyositis, Goodpasture s syndrome, myasthenic syndrome, pemphigus, and obliterative bronchiolitis. 

The aminopyridines (4-aminopyridine 3,4-diaminopyri-dine) accelerate spontaneous exocytosis at central and peripheral synapses. There is also an increase in the number of transmitter quanta released by a nerve action potential. This is probably the result of increased Ca++ inflow at the terminals due to a reduction of K+ conductance and prolongation of the nerve action potential. Muscle strength is increased in patients with the Lambert-Eaton myasthenic syndrome and in others poisoned with botuUnum E toxin (discussed later). Improvement in uncontrolled spasms, muscle tone, and pulmonary function is noted in patients with multiple sclerosis or long-standing spinal cord damage. Side effects that limit clinical utility include convulsions, restlessness, insomnia, and elevated blood pressure. Of the two agents, 3,4-diaminopyridine is the more potent and crosses the blood-brain barrier less readily. 

Guanidine hydrochloride is the drug of choice in the management of patients with myasthenic syndrome and may be of use in the treatment ofbotulinum intoxication. Its ability to enhance transmitter release may involve a block of K+ channels and prolongation of the nerve action potential. 

Kaminski HJ and Ruff RL. The myasthenic syndromes. In Schultz SG, Andreoli TE, Brown AM (eds.). Molecular Biology of Membrane Transport Disorders. New York Plenum, 1996. 

Grassi C, Magnelli V, Carabelli V, Sher E, Carbone E (1994) Inhibition of low- and high-threshold Ca2+ channels of human neuroblastoma IMR32 cells by Lambert-Eaton myasthenic syndrome (LEMS) IgGs. Neurosci Lett 181 50-56. 

Lang B, Newsom-Davis J, Prior C, Wray D (1983) Antibodies to motor nerve terminals an electro-physiological study of a human myasthenic syndrome transferred to mouse. J Physiol 344 335-345. 

O Neill JH, Murray NM, Newsom-Davis J (1988) The Lambert-Eaton myasthenic syndrome. A review of 50 cases. Brain 111 ( Pt 3) 577-596. 

Key words Motor neuron diseases, amyotrophic lateral sclerosis (ALS), spinal muscular atrophy (SMA), peripheral neuropathies, Charcot-Marie-Tooth diseases, hereditary motor and/or sensory neuropathies (HSMNs), congenital myasthenic syndromes, neuromuscular junction, muscular dystrophies, Duchenne s disease. 

The term classical PNS is reserved for the PNS in which the association with cancer is common and includes encephalomyelitis, limbic encephalitis, paraneoplastic cerebellar degeneration, and paraneoplastic opsoclonus myoclonus (OM), as well as sensory neuronopathy (SN), chronic gastrointestinal pseudo-obstruction, Lambert Eaton myasthenic syndrome (LEMS), and dermatomyositis [14]. This chapter does not include dermatomyositis. 

Mason WP, Graus F, Lang B, Honnorat J, Delattre JY, Valldeoriola F, et al. Small-cell lung cancer, paraneoplastic cerebellar degeneration and the Lambert-Eaton myasthenic syndrome. Brain 1997 120(Pt. 8) 1279-1300. 

Nagashima T, Mizutani Y, Kawahara H, Maguchi S, Terayama Y, Shinohara T, et al. Anti-Hu paraneoplastic syndrome presenting with brainstem-cerebellar symptoms and Lambert-Eaton myasthenic syndrome. Neuropathology 2003 23(3) 230-238. 

O Suilleabhain P, Low PA, Lennon VA. Autonomic dysfunction in the Lambert-Eaton myasthenic syndrome Serologic and clinical correlates. Neurology 1998 50(1)88-93. 

Wirtz PW, Willcox N, Roep BO, Lang B, Wintzen AR, Newsom-Davis J, et al. HLA-B8 in patients with the Lambert-Eaton myasthenic syndrome reduces likelihood of associated small cell lung carcinoma. Ann NY Acad Sci 2003 998 200-201. 

Wirtz PW, Willcox N, van der Slik AR, Lang B, Maddison P, Koeleman BP, et al. HLA and smoking in prediction and prognosis of small cell lung cancer in autoimmune Lambert-Eaton myasthenic syndrome. J Neuroimmunol 2005 159(l-2) 230-237. 

Fukuda T, Motomura M, Nakao Y, Shiraishi H, Yoshimura T, Iwanaga K, et al. Reduction of P/Q-type calcium channels in the postmortem cerebellum of paraneoplastic cerebellar degeneration with Lambert-Eaton myasthenic syndrome. Ann Neurol 2003 53(1) 21-28. 

Newsom-Davis J. Therapy in myasthenia gravis and Lambert-Eaton myasthenic syndrome. Semin Neurol 2003 23(2) 191-198. 

Sanders DB. Lambert-eaton myasthenic syndrome Diagnosis and treatment. Ann NY Acad Sci 2003 998 500-508. 

A 51-year-old man developed a myasthenic syndrome which resolved when lithium was withdrawn (200). The authors referred to three other previously reported cases of lithium-induced myasthenia. 

Ronziere T, Auzou P, Ozsancak C, Magnier P, Senant J, Hannequin D. Syndrome myasthenique induit par le lithium. [Myasthenic syndrome induced by lithium.] Presse Med 2000 29(19) 1043-4. 

Neuromuscular disease is a very broad term that encompasses many diseases and ailments which either directly, via intrinsic muscle pathology, or indirectly, via nerve pathology, impair the functioning of the muscles. Diseases of the motor end plate include myasthenia gravis and its related condition Lambert-Eaton myasthenic syndrome. Tetanus and botulism are bacterial infections in which bacterial toxins cause increased or decreased muscle tone, respectively. 

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