--on neuronopathy/ganglionopathy at Johns Hopkins is Dr. Abhay Moghekar (who I have personally corresponded with in the past); he's written a number of papers about this and how hard it is to diagnose definitively, at least until we get better ways of imaging the dorsal root ganglia--although there are some new technologies that have improved such imaging (though they are not yet widely available).

We've certainly discussed this in a few threads in the past:

http://neurotalk.psychcentral.com/ar.../t-110411.html

http://neurotalk.psychcentral.com/ar.../t-142219.html