Hi, Angel19291. This is a great place to be! And it sounds like you need the support. The first thing you need to try to do is relax. I know that's not easy when a child is involved but she is going to follow your lead and you need to stay strong in front of her. Freak out all you want in private.
If she has MG, it is manageable. Yes, it will change both of your lives but it does not mean she can't have a good life. I had MG all of my life - misdiagnosed as lazy eye at age 10 - and didn't get diagnosed until age 41. I simply altered my physical activities up until my 30's when I kept getting worse because I wasn't on drugs.
First, I'm sorry your daughter is having health problems at such a young age. If the doctors think she has MG, there is another group of diseases called Congenital Myasthenic Syndromes (CMS) that are sort of like MG's cousin! MG is an autoimmune disease that causes not enough "muscle gas" whereas CMS is a genetic disease that can cause not enough or too much of it.
Have they checked some basic things like her thyroid function or a chemistry panel, looking at glucose? Are they sure she doesn't have diabetes? The mood thing is why I was asking about that. When glucose gets low, you can have all sorts of symptoms, including weakness.
As far as the calves being tight go, when muscles get weak, they can get tight and cramp up. With people who have MG, it tends to happen more quickly than with those without it. Marathon runners or other athletes have that happen but it's from "overuse." MGers get to the point of "overuse" much more quickly.
I have been having trouble with my calves lately and have been waking up with them cramping. Make sure your daughter is well-hydrated. Has she ever complained of pain in her muscles?
If she does a lot of sitting, you might watch to see if she tenses up her muscles. Or if she "perches" her leg on the ball of the foot. That will tense up the calf muscles. Also, if she has her legs in a 90 degree position too often, those back of the leg muscles tend to need more stretching out. They can easily get too weak by being in one position too long.
What you might want to ask your daughter is if she thinks objects are blurry. A 4-year old, no matter how smart, may not be able to tell you if they are seeing double. Double vision can be off to the side, in front, up, down, close, far and everything in between! I had blurry vision, which I later found out was double vision. With MG, if you close one eye, the blurriness and double vision goes away. I'm surprised the eye doctor did not do more to explain that or test for it. A neuro-ophthalmologist would do more specific tests and be more thorough. Sometimes children need to see "adult" doctors.
MG makes muscles weak. What people don't understand is that when your muscles are weak, it affects the brain too. You can get to a point where you simply cannot even handle a conversation. The emotional response is probably normal. Stress can make MG worse and make someone even more emotional! It's hard to explain if you don't have it. But you can get so run down that you literally cannot cope with anything, physical or mental. And that's very frustrating! Emotions just naturally follow that.
If she has MG, you need to know that we get worse the more we do. Activities should be alternated with rest. Walking around at Disneyland was probably too much for her. You combine heat, which makes MG worse, with a sustained or repetitive activity like walking, and MG can get much worse. She may need to nap more for awhile. She should get an adequate amount of sleep at night, probably more than the average 4 year-old.
I know that waiting for test results isn't easy. But try to relax and know that this disease, if she has it, is manageable. There's a big learning curve to it though and you will want to know as much as you can in order to help her. But wait until you get those results and a diagnosis. Keep an eye on her, make sure she doesn't overdo activities. If she gets really weak or short of breath, you'll need to go to the ER. Don't panic! It simply means she would need some medications and possibly oxygen.
When you find out what's going on, please come back and we can give you more information. In the meantime, you need to take care of yourself too! Stress doesn't help anyone. And don't underestimate the resiliency of children. Sometimes they cope better than adults!
Take care.
I hope you get answers soon.
Annie
I wanted to add that MG doesn't stay only ocular in very many people. If you think she has weakness anywhere else, like her swallowing muscles, neck muscles or anywhere south of that, you need to tell the neurologist right away. If they are not an MG expert, they may not "get" this disease. And there's a lot to know AND understand.