You know what's really nutty about monomelic amyotrophy? You can see it.
Granted, you can't see it in the literal, microscopic, holy-crap-there-goes-another-neuron sense, but you still get to watch it in action.
Hypothetically... say you have cancer. You know it's in an internal organ. You know it hurts. It's beneath your skin (assuming it's not skin cancer) and you don't have to look at it.
As I sit here, my tricep is going crazy. It's twitching around like you wouldn't believe. It's twitching because the motor neuron that tells that muscle either "FIRE!" or "chill, baby" is dying. As a result, my tricep gets pieces of info that cause it to spasm uncontrollably.
Remember the movie Crimson Tide where the nuclear sub gets part of a transmission about firing it's ICBMs? Gene Hackman & Denzel Washington go nuts about whether or not to launch the nukes? They totally freak out & try to arrest each other as they inch closer to all out armageddon. One of them wants to launch, one wants to wait for confirmation. Well, that's what's goin' down in my tricep.
Except my tricep isn't as devastatingly handsome as Denzel, as ferocious of an actor as Hackman, and - to my knowledge - not as radioactive as a nuclear sub.
Anyway - here's to hoping (raises a beverage of some sort) you never have to watch a disease lay waste to an appendage. I don't know for sure, but I have a feeling that out-of-sight truly is out-of-mind when it comes to an ailment whomping on your person.