Reply To: Father in Law….demyelinating neuropathy with no causes found…

You have a CoE about 40 miles North of you, Johns Hopkins University Medical School here:  https://www.gbs-cidp.org/gbs_cfe/johns-hopkins

And the renowned Dr David Cornblath heads the list of specialists there. But I would first explore the possible Lyme connection as Ron suggested (based on his hands-on experience).