ive had PN for 14 years now almost. Large fiber confirmed via emg/ncs, most likely with small fiber involvement now too, though ive never been tested for that. From the beginning my arms would get very tired and heavy very quickly if they were raised at or above the shoulder level. i have to put them down for a few minutes to finish what i started. i might have to do that several times. i also drop things all the time now. I know mine isnt TOS because i have the same thing in my legs, quickly tired and heavy walking up stairs, running or walking any distance.