, does your uncle like apricots? If so, get him to eat lots of dried apricots (untreated ones, preferably: the brown ones. The brightly orange coloured ones are treated with sulphur which causes flatulence). Apricots have lots of Magnesium and in dried ones the concentration is even higher. Mg helps against cramps and organically bound Mg is easier to take up for the body than the anorganic stuff in pills.
Also, a diet rich in vitamin B helps the nerve tissue to recover.
I know it's an idiotic example, but we once had a dog who suffered a severe brain injury before birth and had cramps and spasms (his mother had fallen down the stairs, 2 days before the puppies were born). The vet treated him with high doses of vitamin B and within a few weeks the little chap was almost completely healed. Of course a young organism heals faster but it might still be worth a try.
Also, your uncle being in hospital might be a good chance to raid his room for hidden pills.