Unfortunately, axonal damage--meaning the nerve fibers, as opposed to their myelin sheathings, have been attacked--is very common in blood cancer patients. Some get it as a side process of the cancer itself, usually through the intermediation of monoclonal antibodies (M-proteins) that are a feature of many blood cancers (these tend to interact with proteins in the nerves and degenerate them), but more often it is a result of chemotherapy--many chemo agents, especially those based on metals, are very neurotoxic. (was

Was he on any of these chemo agents?

Nerves do regenerate--but very slowly (maybe even more than two years) and not always completely. If chemo was the culprit, once those substances are withdrawn, he should see at least some improvement over time, though the extent of the recovery is speculative.

You should come post over at the peripheral neuropathy forum:

http://neurotalk.psychcentral.com/forum20.html

Lots of knowledge and expertise there.