Hi, Kate. Welcome! I'm sorry you are going through diagnostic hell.
I'm not one to mince words, especially when someone has not gotten good care. And, oh boy, do I have "thoughts."
First, MG is all about weakness upon exertion that gets better with rest, cold, Mestinon, Tensilon and other MG drugs.
Throwing drugs at symptoms is not good medicine. Drugs are not benign and could cause even more problems. Provigil, for example, does help with some MG fatigue but can also make MG worse. Why the heck they are giving you Wellbutrin is beyond me. Are you depressed? If not, why did they give you an antidepressant? Depression does not cause antibodies to be positive (which your antibodies were, by the way) or ptosis or generalized weakness.
Paresthesias are not caused by MG. They can be caused by the Graves you had, B12 deficiency and LOTS of other causes including electrolyte imbalance. Did they check your B12?
3 - 4% of patients with MG only have modulating antibodies. I am one of those patients. Having an IgG subclass deficiency (i.e., IgG3) can also cause MG antibodies to not look positive. If you are on steroids or if a doctor runs the antibodies while you are on steroids or shortly thereafter, the antibodies will more than likely be negative. The job of steroids is to get rid of the autoimmune process and make the antibodies go away. Duh! So if your docs ran that while you were on steroids, the test is not accurate anyway and should be redone.
You can see a neuro-ophthalmologist to have them evaluated any eyelid droop, aka ptosis (toe-sis). They can determine with their tools if you have fatigable ptosis, a hallmark of MG. Does your blurry/double vision go away when you close one eye? If so, that is binocular vision and that is indicative of MG too (it can be caused by other things though). Does it get worse when you do an "upward gaze?" MG gets worse upon exertion.
You can see a pulmonologist, who can do very specific breathing tests like MIP (maximum inspiratory pressure) and MEP (maximum expiratory pressure) that show neuromuscular weakness. This is a very good idea because they can track progress of MG and can compare baseline readings to when you may get worse. Breathing muscles/chest wall muscles get weak in MG.
You can find a GOOD neurologist who is an MG expert AND nice. An MG expert will understand that Acetylcholine Modulating antibodies are positive in 3-4% of MG patients and are very specific to MG. People just don't make antibodies for no reason!!!
And you have Graves, which quite a few people with MG have. Some people tend to get more than one autoimmune disease in their life. I have MG and celiac disease, for example.
The book "Neuromuscular Junction Disorders: Diagnosis and Treatment" by Meriggioli, Howard and Harper is a very good book. You will find that antibody info in it.
If you have MG, you need to be very careful of getting hot, either by going out in hot weather or getting an infection, etc. Heat makes MG much worse.
If your breathing is getting worse, you absolutely need to have someone see you immediately. Breathing in MG can get rapidly worse and only a doctor and doing pulmonary function tests, arterial blood gases and oxygen saturation tests can tell if you are in trouble.
You need to be very careful with steroids for two reasons. One, MG can temporarily get worse when you first start taking them. Two, if you get "hooked" on them, they cause LOTS of side effects like secondary diabetes, bone demineralization, infections, glaucoma, etc. And if you go off of steroids too quickly, you can have an adrenal crisis, which is life threatening!! Some doctors do NOT understand how to give steroids well. For example, like doing every other day to keep your adrenal glands working. When you are given long term steroids, your adrenal glands tend to just sit back and not work. Why should they have to since artificial steroids are doing their job?!
If you want more information, go to
www.myasthenia.org or
www.mdausa.org
My instincts about your care is that it has not been good. Throwing drugs at someone and dismissing very real test results is dangerous, especially when you possibly have a disease like MG that can kill someone if it is not treated properly!!! I'm not saying that to scare you. Most people do okay having MG. But if it is untreated, muscle weakness can get so severe that you can stop breathing.
So, get yourself some new doctors, have tests redone, get someone who does other MG tests like a repetitive nerve stimulation test or Single Fiber EMG. You need an "official" diagnosis before having meds. And, please, before you even consider taking meds, read ALL of the prescribing info for them first! Some meds are contraindicated in MG and some meds shouldn't be taken together. Or with certain foods.
I hope you will get some good care soon. I know how frustrating this diagnostic process is. And, meanwhile, your life is put on hold!
Annie