Father in Law….demyelinating neuropathy with no causes found…

I’m writing on behalf of my father in law (FIL), who has been experiencing gradually slowing walking for several years.  Last year, he had surgery on his left foot to repair hammer toes (they remain on right side).  Prior to surgery, his podiatrist had him get a neurologist consult for a discovered drop-foot on the surgery side.  The neuro exam included an EMG, which was not done by the doc but by a tech, and left him with “results consistent with anterior horn cell disease”…yuk, that being ALS or PMA.  Anyway, the neuro said it didn’t matter, he’d be walking a while anyway and they’d test more later, so get the surgery.  The surgery was a success.  But FIL never got back on his feet unassisted as before.  In fact he has a brace for the left foot and uses a walker, and his muscles in both lower legs are atrophying a lot over the past 6 months.  He can go up stairs, he walks, but things are getting to be more of a struggle.

His new neurologist ran an extensive workup, and we had the visibility to be in the room as she personally did a NCT and EMG.  ALS for instance remained in our concerns, even though he lacked several of the signs.  She pronounced it “classic neuropathy”….”demyelinating neuropathy”.  And proceed to point to the screen and show why it was not ALS.  He then has undergone a battery of testing, including lumbar puncture and genetic testing.  All have left us with….nothing abnormal.  No known genetic driver, no indicators of autoimmune etiology.  His arms are fine.  But he has lost his mobility to get out and do things with the family, for now.  I say “for now” since there is good tech that can get him out.

The doc didn’t even give us a final dispositive diagnosis.  Only said “go see this neuromuscular specialist, if you want, see if he wants to do something.”  We have a conference call next week but I’m left with the impression the Dx is going to be “Demyelinating Neuropathy – idiopathic” or something equivalent.  And if that is the case, there is little practical short-term difference than a case of ALS… he will lose his ability to walk.  I say “short term” since it shouldn’t eventually kill him (right?).  He’s 78 presently.  Their house…frankly sucks to live in.  Steps to go upstairs.  Steps to go to the garage, steps to go out front.  Terrible garage setup.  Mother in law wont drive any car but her own, and FIL has a hard time climbing out of it.

So here we are, a few more doc visits upcoming but the vegas odds don’t seem to be on anything to restore him to the way he was.  Such is life. We are all here to support him, include him, and help…but I wanted to ask this community about your experiences with these things:

• Is “idiopathic” a known situation…ie “we know what’s wrong but cant fix it” ?
• He had a positive Lyme test….despite a month of antibiotics…no change. Can Lyme disease do this sort of thing?
• Could it be motor neuron disease…ALS or PMA…. Or is questioning the EMG and neurologist not a useful path? He has no spasticity or fasciculations.   Happy to post his data here if it is helpful.

I bought a used Hoverround on craigslist so we’d have it to take him places with us at least, we need to get him “out and about” more.  Lots of changes are needed soon, my approach is to be ready to help when needed and not tell people what they need.  But my wife and I are only children (with 3 kids of our own) so we are his family and want him to live his best life possible.