Actually, cats can and often do fully recover from strok symptoms fairly quickly. It is very possible that he will regain the full or partial use of his paw and go on like before.
I know that Omega 3 fatty acid can be a useful supplement for cats that have had stroke.
There isn't a lot of information out there, but I am going to go ahead and include a link to a site that seems useful.
Much luck. Let us know how it goes, ok?
My cat, Calamity Jane Grey, had a stroke at age 21 1/3.
She was bent to the left and used the wall as a support to get where she needed to go. Her box habits and appetite were good, though; she was a fighter. She responded to an enzyme treatment out vet prescribed for feline stroke patients, until age overcame her will to live.
If your kitty is anything at all like my Cammie, he'll pull through, especially with the advantage of relative youth.
My wishes for a full recovery - Pip