I
can understand your plight well.
You are right, certain medications particularly muscle relaxants
and antichlinergics, interfere with the results of EMG like baclofen and flexeril or cyclobenzaprine that you are taking. It would be prudent to apprise your neurologist of all the medications you are on, so that the EMG results are appreciated in that light. Muscle biopsy can be taken up after an EMG. Consult your neurologist for his preferences and expertise. Take care.