He has small fiber peripheral neuropathy which has been confirmed by a skin biopsy which is the gold standard test to diagnose small fiber peripheral neuropathy. so that much is set. what cani has to do is explain how the symptoms of his peripheral neuropath prevent him from being able to work. Pain, numbness, weakness, balance difficulties, unsteady gait,heavyness in legs etc prevent him from being able to sit, stand, walk, run, bend, climb, reach, kneel, squat etc for specific periods of time or not at all.
I have peripheral neuropathy also, only large fiber instead of small which also prevent me from doing the above things for more than a very small period of time. It is a very painful condition. I was approved for peripheral neuropathy and asthma after a hearing. The purpose of the hearing turned out to be to set an onset date for my disability, not whether i would be approved.