I was diagnosed because of my symptoms and by a neurologist doing tests to rule out other autoimmune diseases. A good rheumatologist should also be able to diagnose you. It's easier if fibromyalgia (FM) also accompanies your symptoms. Not easier to live with, but easier to get a diagnosis if you also have it.
Many things have to be ruled out....and it takes someone at the very top of the medical field to make certain the proper tests are given and other illnesses ruled out. MRI's with and without contrast are helpful, certain nerve conduction tests, trigger points and the pain caused, and a host of other neurological conditions.
I hope you find someone personable as it makes all the difference in the world. Modern equipment is a must, so please bear that in mind. If possible, have the MRI's read by as many doctors as possible, not just reading of the report itself. Often one doctor will pick up something another one has missed. Good luck. Yours, Lenora.