Hi Steff,
I've had a number of NCS/EMGS in the last 7 years - each was different depeding on the doctor and the extent of my symtoms (as the PN spread body wide - so did the testing).... they are probably looking just at the areas they feel are affected - which they did to me at first... the last one was body wide as symtoms are now - but again, seems like depends on your individual symtoms and how widespread any potential damage the neuro may feel is there.....
Hopefully this test will give them the info they need