Talk:Lambert–Eaton myasthenic syndrome

Treatment
- review from my alma mater. JFW &#124; T@lk  22:10, 27 December 2010 (UTC)


 * I have scanned a number of recent reviews of paraneoplastic neurological syndromes. I found only Rees (2004) particularly useful because he addresses some important points (e.g. cerebellar involvement, not mentioned in Mareska or Verschuuren). The others simply rehash the same stuff, usually citing the 1988 Brain article.
 * A strange one is, which completely bypasses anti-P/Q-VGCC antibodies and instead mentions antiglial nuclear antibody (identified by the same group). I can find no other review that attached importance to these and I am inclined to omit this. JFW &#124; T@lk  12:08, 31 December 2010 (UTC)


 * This one looks authoritative and is fairly recent. I might eventually use it to back up some stuff, but most of its coverage of LEMS is identical to what we are already saying on the basis of Mareska and Verschuuren.
 * JFW &#124; T@lk  12:08, 31 December 2010 (UTC)
 * JFW &#124; T@lk  12:08, 31 December 2010 (UTC)

More sources
added to the opening words of the article. This is a review in Japanese, and from the abstract I can't see clearly whether there is any information in that article that definitely needs to be sourced from there and cannot be sourced to any of the other reviews already cited.


 * The source confirms the disease acronym at first glance; it in no way distracts the reader, damages the article, nor negates the pending GA review; and the abstract is in english. Rcej (Robert) - talk 09:36, 23 February 2011 (UTC)


 * So does Mareska's article, in English, in the abstract. To be honest, I found it a bit distracting. We don't usually provide sources for nomenclature in medical articles, unless the verifiability is doubtful or disputed. JFW &#124; T@lk  21:40, 23 February 2011 (UTC)

is an immunological review that might be useful, but I need to read it first. JFW &#124; T@lk  08:35, 23 February 2011 (UTC)


 * This was vaguely useful, but I decided not to cite anything from section 4 ("compensatory mechanisms") because its findings don't seem to have applied to LEMS subjects. JFW &#124; T@lk  23:46, 23 February 2011 (UTC)

10.1055/s-2008-1062260 mentions the same points as Mareska, so does not need citing separately. I can't find any novel points in it. JFW &#124; T@lk  22:13, 23 February 2011 (UTC)

LEMS vs myasthenia gravis
From the lead section, paragraph 2: "The diagnosis is usually confirmed with electromyography and blood tests; these also separate it from myasthenia gravis." From "Diagnosis", paragraph 2: "A similar pattern is witnessed in myasthenia gravis," in reference to CMAP. Does EMG distinguish LEMS from myasthenia gravis? Axl ¤  [Talk]  10:19, 14 March 2011 (UTC)


 * Yes. The characteristic >200% increase in amplitude in exercise is what distinguishes LEMS from MG. Will make it better. JFW &#124; T@lk  10:51, 14 March 2011 (UTC)


 * So the pattern is similar at rest? Exercise or a "rapid burst of stimuli" allows the distinction? What is "a rapid burst of stimuli" in this context? Axl  ¤  [Talk]  09:26, 15 March 2011 (UTC)


 * The source is not very clear as to whether the pattern is similar at rest. Given that myasthaenia gravis is fatiguable, this may well be the case. I will need to verify this with another source (or with Pizzaman). The "rapid burst of stimuli" is as indicated between the brackets (10s of 20Hz electric stimuli). JFW &#124; T@lk  23:36, 15 March 2011 (UTC)
 * The text does not indicate electrical stimuli. Axl  ¤  [Talk]  09:31, 16 March 2011 (UTC)
 * I have added this. Axl  ¤  [Talk]  09:33, 16 March 2011 (UTC)

Questions for JFW from Axl
The section "Signs and symptoms" contains several uses of the word "some" to describe the number of LEMS patients with a given symptom. Any chance of a table showing the percentage of patients who have those symptoms? Axl ¤  [Talk]  10:20, 22 March 2011 (UTC)


 * The sources don't provide hard figures that could be used for this purpose. Mareksa only states 75% have orthostatic hypotension. Suggestions for synonyms of "some" are welcome. JFW &#124; T@lk  20:31, 22 March 2011 (UTC)

From "Signs and symptoms", paragraph 3: " Reflexes are typically depressed, but can be characteristically augmented by muscle use." I don't understand what this means. Axl ¤  [Talk]  10:22, 22 March 2011 (UTC)


 * A characteristic feature of LEMS, both clinically and myographically, is the augmentation of power by exercise. Therefore, reflexes are difficult to elicit at rest, while they may normalise after getting the patient to contract the affected muscles for a while. This is because the calcium channels eventually deliver the required amount of calcium, albeit more slowly, into the muscle after repeated stimulation. Suggestions for clarification would be welcomed. JFW &#124; T@lk  20:31, 22 March 2011 (UTC)
 * How about "At rest, reflexes are typically reduced. With muscle use, reflex strength increases."? Axl  ¤  [Talk]  09:20, 28 March 2011 (UTC)

From "Causes", paragraph 1: "LEMS is often the problem that leads to the diagnosis of the lung cancer." I find this very hard to believe. Does the source really state this? The next sentence states "of the people with small-cell lung cancer, 1–3% have LEMS." Axl  ¤  [Talk]  10:26, 22 March 2011 (UTC)


 * What I meant was that those people with LEMS that have an underlying lung cancer are often asymptomatic otherwise. I will try to rephrase this. JFW &#124; T@lk  20:31, 22 March 2011 (UTC)

From "Causes", paragraph 1: "The vast majority of small-cell lung cancer is linked with smoking tobacco." I don't see how that's relevant to the article on LEMS. Would you be happy to delete the sentence? Axl ¤  [Talk]  10:27, 22 March 2011 (UTC)


 * In a sense, smoking causes LEMS by predisposing to SCLC, and this probably why Verschuuren mentions it so prominently. I have no problem with removing the sentence. JFW &#124; T@lk  20:31, 22 March 2011 (UTC)

The section "Causes" uses the hyphenated "small-cell lung cancer", while the lead section does not use a hyphen. Perhaps you remember a discussion at WikiProject Medicine about this? At least be internally consistent within this article. Axl ¤  [Talk]  10:30, 22 March 2011 (UTC)


 * I have simply changed it to the term used by MESH. JFW &#124; T@lk  20:31, 22 March 2011 (UTC)

From "Causes", paragraph 2: "Myasthenia gravis, too, may happen in the presence of tumors (thymoma, a tumor of the thymus in the chest); people with MG without a tumor and people with LEMS without a tumor have similar genetic variations that seem to predispose them to these diseases." Is MG (with or without thymoma) a cause of LEMS? Is MG associated with LEMS? If not,this text is not relevant here. Axl ¤  [Talk]  10:41, 22 March 2011 (UTC)


 * LEMS and MG are very similar, being the two main acquired myasthenic syndromes. Verschuuren makes a number of observations about MG to allow a parallel or a constrast. I think we ought to say that both diseases have a similar immunological basis. I agree that the mention of thymoma is a bit off-topic. JFW &#124; T@lk  20:31, 22 March 2011 (UTC)

Anitbodies
10.1016/S0140-6736(11)60165-7 (Lancet seminar on SCLC, in press) - antibodies against SOX family proteins distinguish LEMS from SCLC from non-tumour LEMS. JFW &#124; T@lk  07:43, 27 June 2011 (UTC)


 * 10.1016/S1474-4422(11)70245-9 - Lancet Neurol (as identified by Nbaumann) needs to be incorporated into the article.
 * 10.1111/j.1749-6632.2012.06769.x needs consideration - antibodies (Ann NYAS).
 * 10.1111/j.1749-6632.2012.06772.x is about the active zones on the NMD (Ann NYAS).
 * 10.1097/WNF.0b013e31825a68c5 reviews the aminopyridines. JFW &#124; T@lk  14:04, 4 August 2013 (UTC)