Hi Orolibre

Thanks for the background info on your friend. Your theory of his stress issues activating an underlying autoimmune condition are quite probable. What he's been through may have exhausted his body's supply of essential nutrients leading to illness. He could have a deficiency in B12 which can cause PN symptoms. Has he been tested for this? As MrsD will tell you the results will often come back saying levels are normal when they may actually be low because of inadequate range often used. If he can find out the actual result number it is more useful.

There is an extensive thread on B12 deficiency at:

http://neurotalk.psychcentral.com/thread85103.html

From what I've read on this forum and other websites his symptoms do correlate with PN but almost at the extreme end with something else going on (the blacking out). It's good that his doctors seem to be doing a thorough search - however some autoimmune diseases can be very elusive for years.

It could also be a delayed adverse effect from one or more of the medications he was on. Has he been taking any statins?
Unless he has known exposure to things like Lyme disease, heavy metals or other toxins it may be worth eliminating the more likely candidates first - testing can be very expensive.

Neuropathy seems to present differently in everyone so while few may have his exact symptoms I hope the info you find here can help him work out possible causes. Unfortunately there is usually no quick fix for PN but finding a cause (or an underlying condition) may help optimize treatment.

It's good that he has you as a supportive friend during this tough time.