{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,15]],"date-time":"2026-05-15T13:10:36Z","timestamp":1778850636571,"version":"3.51.4"},"reference-count":16,"publisher":"Wiley","issue":"5","license":[{"start":{"date-parts":[[2009,8,31]],"date-time":"2009-08-31T00:00:00Z","timestamp":1251676800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Muscle and Nerve"],"published-print":{"date-parts":[[2009,11]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:p>The purpose of this study was to investigate the clinical and electrophysiological efficacy of 3,4\u2010diaminopyridine (DAP) in patients with Lambert\u2013Eaton myasthenic syndrome (LEMS) in a randomized, double\u2010blind, cross\u2010over drug trial. The diagnosis of LEMS was made based on the combination of fluctuating muscle weakness, diminished or absent reflexes, and more than 60% increment of the compound muscle action potential (CMAP) amplitude after brief exercise or 50\u2010H<jats:sc>Z<\/jats:sc>stimulation on a repetitive nerve stimulation (RNS) test. Evaluations were done at baseline, with placebo, and with 3,4\u2010DAP (up to 75\u201380 mg\/day). Assignment of placebo or 3,4\u2010DAP was done in a double\u2010blinded manner. Measurements included subjective symptoms score, objective clinical measurements [LEMS classification, muscle strength score, quantitative myasthenia gravis (QMG) score] and RNS test and single\u2010fiber electromyography (SFEMG). The differences between placebo and baseline values (placebo change) were compared with the differences between 3,4\u2010DAP and baseline or placebo values (DAP change). Seven patients with LEMS (QMG score &gt;9) participated in the study. One patient had major side\u2010effects with 3,4\u2010DAP and withdrew from the study. Statistically significant efficacy was noted with DAP change (<jats:italic>N<\/jats:italic>= 13) compared with placebo change (<jats:italic>N<\/jats:italic>= 7) according to the subjective symptoms score (<jats:italic>P<\/jats:italic>= 0.01), LEMS classification (<jats:italic>P<\/jats:italic>&lt; 0.001), muscle strength score (<jats:italic>P<\/jats:italic>&lt; 0.006), QMG score (<jats:italic>P<\/jats:italic>= 0.02), and CMAP (<jats:italic>P<\/jats:italic>= 0.03). For long\u2010term treatment, 2 patients preferred 3,4\u2010DAP, 1 chose guanidine hydrochloride, 1 preferred pyridostigmine, and 2 chose no treatment. A randomized, double\u2010blind, cross\u2010over drug trial of 3,4\u2010DAP showed significant efficacy over placebo in patients with LEMS. As a long\u2010term treatment, however, not all patients preferred this drug. Muscle Nerve, 2009<\/jats:p>","DOI":"10.1002\/mus.21422","type":"journal-article","created":{"date-parts":[[2009,8,31]],"date-time":"2009-08-31T15:01:55Z","timestamp":1251730915000},"page":"795-800","source":"Crossref","is-referenced-by-count":82,"title":["3,4\u2010Diaminopyridine is more effective than placebo in a randomized, double\u2010blind, cross\u2010over drug study in LEMS"],"prefix":"10.1002","volume":"40","author":[{"given":"Shin J.","family":"Oh","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gwendolyn G.","family":"Claussen","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yuki","family":"Hatanaka","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Marla B.","family":"Morgan","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2009,8,31]]},"reference":[{"key":"e_1_2_5_2_2","doi-asserted-by":"crossref","first-page":"260","DOI":"10.1016\/S0022-3565(25)22023-7","article-title":"Effects of 4\u2010aminopyridine and 3,4\u2010diaminopyridine on transmitter release at the neuromuscular junction","volume":"22","author":"Thomsen RH","year":"1983","journal-title":"J Pharmacol Exp Ther"},{"key":"e_1_2_5_3_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1468-1331.2006.01476.x"},{"key":"e_1_2_5_4_2","doi-asserted-by":"publisher","DOI":"10.1002\/mus.20389"},{"key":"e_1_2_5_5_2","doi-asserted-by":"publisher","DOI":"10.1212\/WNL.34.10.1324"},{"key":"e_1_2_5_6_2","doi-asserted-by":"publisher","DOI":"10.1002\/(SICI)1097-4598(199607)19:7<903::AID-MUS15>3.0.CO;2-J"},{"key":"e_1_2_5_7_2","doi-asserted-by":"publisher","DOI":"10.1212\/WNL.55.1.16"},{"key":"e_1_2_5_8_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1749-6632.1998.tb11015.x"},{"key":"e_1_2_5_9_2","first-page":"362","volume-title":"Myasthenia gravis: the second international symposium proceedings 1959","author":"Lambert EH","year":"1961"},{"key":"e_1_2_5_10_2","volume-title":"Electromyography. 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