James:

Apparently there are some differences between how "pure" myotonia and neuromyotonia appear and sound on an EMG and I'm not very familiar with them. I had been under the impression that some doctors might have trouble distinguishing the differences, but as I said, the gold standard when "pure" myotonia is suspected is genetic testing. With Becker myotonia congenita, the recessive from of the disorder, you usually wouldn't have a family history unless you live in a very genetically isolated area where people have been marrying cousins for a while. I don't think that's a problem in England :-)

Additionally, sometimes the dominant form of myotonia congenita and sodium channel myotonias has whats called "low penetrance", meaning the symptoms are so mild in some individuals that it's not apparent they have it.

Type of Myotonia: Becker

Country: USA