There are several blood tests that can be helpful in addition to the EMG test. All standard causes of peripheral neuropathy, including diabetes, low thyroid, folate and B12 deficiency and excess alcohol intake should be tested for since they are all treatable. There are inflammatory markers in the serum ( sed rate and CRP) and specific antibodies that cause demyelination and nerve damage. A spinal tap can show high protein levels but normal levels can occur in CIDP. Having one autoimmune disease increases the chance of having others, and I think it is prudent to have a rheumatologist on your team and be checked for other autoimmune diseases, some of which cause peripheral neuropathy themselves, like lupus, rheumatoid arthritis and mixed connective tissue disease. These can cause muscle inflammation also (myositis) which can be ruled out with CK and aldolase blood tests (muscle enzymes). That’s a lot of blood tests but would provide a comprehensive picture of the situation and perhaps some of what shows up might be treatable. The inflammation and cytokine release is what causes the exhaustion. I believe in leaving no stone unturned and treating every treatable factor for the best outcome.