'A Patient Voice' Community

Hi everyone, this is the first time I have ever posted on a discussion board. I am desperate for answers so I am hoping that someone can shed some light on my situation.
About two years ago, I started having aching pain in my left arm. It was bothersome for about three days and then became extremely painful one day, accompanied by an episode lasting about two hours in which I lost nearly all feeling in my arm, it was numb and tingly, and it was pretty much dead; I couldn't even lift it. I also experienced slightly slurred speech and confusion. They thought I had a stroke but all my tests were fine. I continued to experience pain, numbness, weakness, and tingling, but within three weeks I was back to normal, as if nothing happened.
About four months ago, the exact same thing happened, same pattern, minus the slurred speech and confusion. Again, a slew of tests, and nothing. Again, within about three weeks, back to normal.
Three days ago, I felt the familiar pain in my arm. It starts out small, like annoying really, and gradually becomes worse. Today, it is hurting a lot; ibuprofen and naproxen barely touch the pain. There are no sharp pains, it's like a dull, deep ache, and my arm feels heavy. I feel like I want to chop it off. During the two previous episodes, at times I could hardly pick up my arm. Even something as simple as buckling my seat belt was difficult and felt like it took all my effort.
I have had MRI's of my brain twice and my cervical spine, but nothing seems abnormal. I also had a nerve conduction study which was normal. I have had umpteen blood tests and even a smear, nothing exciting there.
Both my primary doctor and the two neurologists I have seen don't have any clue.
I have done tons of research trying to explain my symptoms with no luck.
If anyone has any ideas at all, I would really appreciate hearing them.
Thank you!