I’ve been living with myasthenia gravis for 66 years now, 26 of those years without a diagnosis. Muscle cramping was always a consistent symptom that I never associated with MG. In fact, early in my diagnosis when I asked my neurologist about my frequent cramping, he stated that he didn’t think it was part of MG and that none of his other patients complained about them (sigh).
Just to be clear, I’m not talking about the occasional Charlie horse that everyone gets now and then, but a crippling kind of cramping that contorts my feet, hands, legs, and sometimes even my tongue into a shape that I would be unable to do otherwise. Sometimes the cramps last for a few seconds or minutes, but sometimes they go on for hours, inflicting a special type of exhausting pain that is both frustrating and agonizing.
When I started to talk to other MG patients, I found that they do indeed complain about muscle cramping. In fact, almost everyone of them had experienced the type of severe muscle contortions I was living with. In the support groups I lead, it is the second most talked about problem, following closely behind general weakness.
This fact led me in search of answers. Some of the common causes of muscle cramps are dehydration, electrolyte imbalances (sometimes caused by high-dose prednisone), Mestinon™ (pyridostigmine bromide), and overuse. Since I had experienced this cramping even before I was diagnosed and placed on Mestinon™ and steroids, and most of my muscle cramping occurs after extended muscle use, I believe my major source of the cramping is overuse.
The problem is that I can’t tell, even now after all these years, how much use is overuse. Some days I can type for hours, or bike a few miles on my stationary bike, or stand for a long time with nary a cramp. Other days a quick drive to the grocery store or doing some drawing or knitting will provoke hours of cramping. I try to set limits for myself and my energy so that I don’t get so weak that my muscles complain. I’ve learned that sometimes I must stop in the middle of a project and leave the rest for another day to avoid the dreaded cramps and accompanying weakness. I also try and drink enough water to avoid dehydration which can certainly aggravate the cramps.
As with any type of advice given here or at a support group, this is what works for me. It may not work for you. Check in with your own doctor before trying anything to cure your cramps. Please consult your treating physician, especially if you are frequently experiencing the contortion type of muscle cramping as your doctor may want to check your electrolyte levels. I hope you can find something that works for you.