I think I understand you. I haven't experienced the "in and out" thing that you describe, or at least not in such an extreme way. I hope they do check you for LEMS, which is a myasthenic syndrome (also autoimmune) that sometimes acts a little different from "typical" (I put that in quotes, because I'm not sure there is such a thing) MG. Sometimes (but not always) people with LEMS are very weak and get stronger when they use the weak muscles.

I don't know if it will be useful, but here's my experience. I have ups and downs that come on gradually and leave gradually over a period of a couple of weeks (except that certain things make me worse all of a sudden, hormonal changes in my monthly cycle and infections like a bad cold). In addition to that, I get gradually and steadily weaker during the day, so that I'm weakest at night. In addition to that, I have spells of intense weakness, usually in the late afternoon or early evening, or late at night before bed, that last about 45 minutes. They come on quite suddenly but go away gradually.

I had a bad spell last night around dinner time. I was sitting at the table and suddenly realized I was "getting weak" (my husband knows what I mean by that--it means it's coming on quickly). My neck and sides were really too weak to hold me up, so I had my husband help me lie down on the floor. After twenty minutes or so, he dragged/carried me to the couch, where I lay for another half hour before I could walk. For the rest of the evening I needed help on and off getting around. I understand that this is different from what you describe, but maybe parts of it will be familiar.

But here's the thing: don't be quick to believe a doctor who tells you "it's not MG, because MG never does [whatever]." MG is a really quirky disease. I once had a neurologist tell me "I have seen about 800 patients with myasthenia gravis in my career, and not one of them walked like you do." Then he diagnosed me with myasthenia gravis. Smart doctor.

At the time, my main symptom was some sort of truncal instability, so that I swayed wildly to the left and right as I walked. I still do that a bit, but now (it's been two and a half years) I have other more typical MG symptoms. So the picture I present now isn't as weird as it was when I had that one weird thing that was over-whelming everything else.

So tell the doctor about the sudden changes, but don't forget to tell him about milder symptoms, too. Tell him things like that it's often hard to stand up from sitting down.

One more thing: sometimes I "fall off my hips"--I suddenly fall forward, but only from the waist up. Then I stand up straight again and continue on my way--carefully, because if I balance myself and don't make any sudden moves, it's less likely to happen. It's as if the muscle systems that catch you when something throws you off balance aren't working properly. Similarly, when I'm so weak that I need help walking (my husband is standing behind me holding me up), if I step on a sock the kids left on the floor, or if he bumps his feet into mine--any little thing--I lose the partial ability to hold myself up at all. At this point, I sometimes knock him, down, too.

Abby

go away spontaneously.

It is not common but does happen.

I hope your "constant companion" has left you forever.