Sam, was your daughter diagnosed through DNA testing? It does sound very extreme, even for paramyotonia congenita.

Is there any way you can get a second opinion about the best medication for her? Dr. Michael Hanna is an expert on ion channel disorders in the UK. Here is his contact information:

Dr. Michael Hanna

This is a chapter from a book that he co-authored on periodic paralysis. It also talks about paramyotonia congenita, which he says overlaps the symptoms of hyperkalemic periodic paralysis. It mentions several medications for treatment, but carbamazepine is not one of them. It's a very powerful epilepsy drug with the potential for some serious side effects that may be more than she needs to control the condition:
Periodic Paralysis

If you can't see him (or if he isn't your doctor already) perhaps he could consult with your physicians.

This forum is primarily for myotonia congenita, which is a different ion channel disorder (chloride instead of sodium). You are certainly welcome to post here and hopefully some of our PMC members will respond. But there is a website specifically for the periodic paralyses which includes paramyotonia congenita. Here is a link the information page:

Paramyotonia Congenita

There is a listserve you can sign up for and perhaps there will be some parents on there who have children with PMC. It is so rare that it's difficult to find support groups dealing with it.

Jan

Type of Myotonia: Thomsen's

Country: USA

Sam:

In addition to the resources Jan pointed you to, there are also many people on the Facebook myotonias group with paramyotonia and other myotonia causing SCN4A mutations. Most SCN4A mutations that I am aware of seem to be dominant...there is usually a parent with it as well, so if she has not already had it, I would ask to have it done.

Type of Myotonia: Becker

Country: USA