Paraneoplastic neurological syndrome is an autoimmune disease caused by distant effect of tumor. Lambert - Eaton myasthenic syndrome (LEMS) is a paraneoplastic disease that is associated with voltage-dependent calcium channel antibodies. These autoantibodies affect especially presynaptic neuromuscular area. A 65 -year-old male patient admitted to hospital with complaint of dizziness, walking difficulty, and difficulty in getting up stairs. Neur ological examination showed mild muscle weakness proximal of lower extremities. Deep tendon reflexes were hypoactive. Sensory nerve conduction was normal in the electroneuromyography. All motor nerve compound muscle action potential (CMAP) amplitudes were decreased. After 10 seconds of exercise, amplitude increased more than 100%. More than 10% decrement was observed at low frequencies in ulnar repetitive nerve stimulation. More than 200% increment was observed with 50 Hz tetanic stimulation. Lung adenocarcinoma was diagnosed with thorax computerized tomography and bronchoscopic biopsy. In the electrophysiological analyses of LEMS, significant amplitude increment is diagnostic with high frequency tetanic stimulation. Increment following short-term exercise is an easier alternative method to tetanic stimulation.
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1. Kleopa KA, Teener JW, Scherer SS, et al. Chronic multiple paraneoplastic syndromes. Muscle Nerve 2000; 23: 1767-1772.
2. Titulaer MJ, Wirtz PW, Kuks JB, et al. The Lambert- Eaton myasthenic syndrome 1988– 2008: a clinical picture in 97 patients. J Neuroimmunol 2008; 201: 153-158.
3. Nakao YK, Motomura M, Fukudome T, et al. Seronegative Lambert- Eaton myasthenic syndrome: study of 110 Japanese patients. Neurol 2002; 59: 1773–1775.
4. Ramos-Yeo YL, Reyes CV. Myasthenic syndrome (Eaton- Lambert syndrome) associated with pulmonary adenocarcinoma. J Surg Oncol 1987; 34: 239-242.
5. Sumitomo M, Uyama T, Kimura S, Hashioka K, Nobuhara K, Monden Y. A case of LambertEaton myasthenic syndrome associated with adenocarcinoma of the lung. Haigan 1989; 29: 167-172.
6. Okudera K, Ebina A, Imai S, et al. A case with adenocarcinoma of the lung accompanied Lambert- Eaton myasthenic syndrome. Nikkyo 1996; 55: 902-907.
7. Milanez FM, Pereira CA, Trindade PH, Milinavicius R, Coletta EN. Lung adenocarcinoma, dermatomyositis, and LambertEaton myasthenic syndrome: a rare combination. J Bras Pneumol 2008; 34: 333-336.
8. Arai H, Inui K, Hashimoto K, et al. Lung adenocarcinoma with Lambert-Eaton myasthenic syndrome indicated by voltage-gated calcium channel: a case report. J Med Case Rep 2012; 6: 281.
9. Bukhari S, Soomro R, Fawwad S, Alvarez C, Wallach S. Adenocarcinoma of lung presenting as Lambert-Eaton myasthenic syndrome. J Investig Med High Impact Case Rep 2017; 5: 1-4.
10. Tang Y, Wang K, Chen Z, et al. Ophthalmoplegia associated with lung adenocarcinoma in a patient with the Lambert–Eaton myasthenic syndrome: A case report. Medicine 2017; 96: e6484.
11. Sanders DB. Lambert-Eaton myasthenic syndrome: clinical diagnosis, immune-mediated mechanisms, and update on therapies. Ann Neurol 1995; 37: 63-73.
12. Titulaer MJ, Maddison P, Sont JK, et al. Clinical Dutch- English Lambert- Eaton myasthenic syndrome (LEMS) tumor association prediction score accurately predicts small-cell lung cancer in the LEMS. J Clin Oncol 2011; 29: 902-908.
13. Oh SJ, Kim DE, Kuruoglu R, Brooks J, Claussen G. Electrophysiological and clinical correlations in the Lambert–Eaton myasthenic syndrome. Muscle Nerve 1996; 19: 903-906.
14. O’Neill JH, Murray NM, Newsom-Davis J. The Lambert- Eaton myasthenic syndrome. A review of 50 cases. Brain 1988; 111: 577-596.
15. Chalk CH, Murray NM, Newsom-Davis J, O’Neill JH, Spiro SG. Response of the Lambert-Eaton myasthenic syndrome to treatment of associated small-cell lung carcinoma. Neurol 1990; 40: 1552- 1556.