Total disablement is relatively infrequent. Some rare cases also involve nearly every muscle and nerve, including the those of the cranial area. Some hallmarks of MMN either with or without conduction block, are high levels of various antibodies. These are only rarely found in ALS and are a fairly reliable indicator. Also, MMN with conduction block does not always have the high level of certain antibodies, but rather a prominent conduction block shown on EMG of one or more motor nerves.
Some patients have both.
Most MMN patients are middle-aged, with a somewhat male predominance, although I know two women who have it. I believe that it was discovered in the eighties when some presumed ALS patients never developed upper motor signs or died. I hope this has been of help to you. I feel it has improved with only vitamins and antioxidants, or perhaps on its own. My neurologist agrees.