I was an airline pilot and I was taking a Boeing 747-400 freighter (therefore no passengers on board) to Anchorage, Alaska in about 2000. The first bout of spasms occurred during this flight. My two young fellow crew thought I had lost it, as the first attack had me literally gasping for breath. The spasms had hit all the back muscle groups from my neck down to my waist. After 20-30 seconds they dissipated, and all returned to normal.
I was able to explain to the crew what I thought was happening, and I quickly reassigned duties so that if I became completely incapacitated these two young pilots would be able to get us to Anchorage. Sure enough, the second spasm hit about 15 minutes later, and the pattern continued for the rest of the 7 hour flight.
I crawled into the crew bunk with a hot water bottle on my back (which helped somewhat) and managed to drag myself back into my seat for the approach and landing into Anchorage. The other two crew were doing all the work- lowering the wheels and flaps, talking to Air Traffic Control, reading checklists and all the flying, while I was only able to monitor what they were doing, and - in between the spasms that were still hitting me- talk to them. But I could not even lift an arm, as the mere thought of just thinking about this movement triggered another spasm.
I told the crew to send a satellite message to our Anchorage base asking for a doctor to meet us on arrival. This was done, but the doctor was as nonplussed as I was as to the cause. He prescribed some anti-spasm tablets and effectively threw up his hands and said he could do no more. This whole scary episode lasted another day, and since then I have never had another attack.
Until yesterday. I am about to visit my GP in one hour for an injection which I hope will reduce the severity of the spasms , which are now affecting the right side of my back. I am otherwise fit and healthy, aged 67 now. I hope this story is of help to someone out there. - Ron