The cause of disease is many times un-known because like a car accident it can be caused by many things, and more times then not it is caused by more then one thing. Most disease are probably what we call- multifactorial. eg-a combination of genetic and enviromental factors. Many times they are the result of over-reaction of our normal defense and repair mechanisms.

For instance celiac. People who have an immune system that is prone to react to gluten, can have a severe and at times life-threatening inflamatory response once exposed to even trace amounts. Whereas others with a somewhat different immune system will have disturbing symptoms but of a much less significant severity. And most of the population can have large amounts of gluten without any consequences.

As to mercury. Trace amounts are probably not harmful in most people, but it is possible that it may harmful in some who are more sensitive to it. This is probably true for almost every substance. It is a huge leap to attribute an autoimmune disease to amalgam, just because the first symptoms were evident after a visit to the dentist. By the same token you could attribute leukemia to ingesting pickles ( we had a patient who was confident that his leukemia was the result of rotten pickles he accidently ate).

coincidence is widespread, causality is sparse. finding the needle of causality in the haystack of coincidence requires meticulous and well-planned research. Even then, mistakes can happen in the understanding of the mechanism of disease.

When such connections are found it is a true celebration for science and for medicine. The discovery of the lack of vitamin B12 as the cause of a fatal debilitating illness; The discovery of insulin; The discovery of the genetic defect responsible for a certain type of leukemia which eventually led to a targeted and very effective treatment .

As to myasthenia, I may be overtly optimistic, but I do think that alongside those who think that the world is still flat, there are others, and there is some progress in the understanding, diagnosis and management of this illness, over the last few years.

There is even a very interesting and innovative clinical trial looking at improvement of muscle contractility in myasthenia. http://clinicaltrials.gov/ct2/show/N...thenia&rank=18. So, yes, it seems there are some who are thinking. Even though I wish there were more.