It's extremely difficult to try and form an accurate neurological opinion regarding your complex case having never reviewed your studies personally. Some of the various results from your extensive testing are patchy and conflicting. For instance, there's a very big difference between a primary muscle disease and polio. If you've had polio (which is a spinal cord disease, NOT a muscle disease), it should show up on the EMG with a specific pattern even if you had it about 50 years ago (which is when the polio epidemic took place in the US, so you're a bit young to have had it unless you were overseas). If the EMG shows primary muscle disease and no evidence of polio, then that should be ruled out completely. Immune causes for a myopathy (muscle disease) are certainly a possiblity as well as thyroid disease or other metabolic causes. One thing to consider is to see an academic neuromuscular specialist who can help you sort things out, put all the clues together, and get definitive testing so that the proper diagnosis is made and treatment initiated. If you're in the area, Drs. Kerry Levin and Robert Shields are outstanding neuromuscular specialists who would be happy to see you. Slides from your biopsy should be brought or sent to an academic neuropathologist or at least sent to AFIP for a second review. This may be also be helpful. Good luck.