Peripheral neuropathy is a known, although rare, side effect of ethambutol. I was taken off the ethambutol a few months ago after experiencing loss of feeling in both feet, and the numbness has improved a lot (slowly) but I still have pain in my legs as well as some numbness in my upper arms, oddly. I also still have balance issues.
I'm following up with vitamin level testing, etc., but wanted to encourage those who may be experiencing this issue that there can be improvement once you discontinue the drug.
FYI, I'm 70 and run 2 miles a day, so quite active.