Suggest Treatment For Non Inflammatory Muscle Breakdown Disorder

My doctor is sending me for a muscle biopsy to look for a non inflammatory muscle breakdown disorder. When I asked what that would include he said that if I googled it I could see a list of the possibilites. I googled it and looked around and have been unable to find much of anything on non inflammatory myopathies. Do you know what disorders/diseases this would encompass? I have proximal muscle weakness in my arms and legs on both sides. I also get tingling/numbness in my legs, again on both sides. I have had a brain MRI that was normal, a cervical spine MRI that didn't show anything that would cause these symptoms (according to my neurologist). I have also had an upper body EMG that was normal, and lots of blood work that was all normal.