If a turkey has neurological symptoms, like losing it's balance and falling over, it may have flipover disease, which is a genetic problem in turkeys. There is no treatment or cure; if the bird is a pet, you can try nursing measures to keep it comfortable when it is having problems. Things like putting it in a small pen with lots of soft bedding, no perch, keeping food and water easy to reach and fastening the containers so they can't tip over, and isolating it from other birds that may attack it when it can't escape or fight back.
Some turkeys don't have it too bad and may live a long time, but the symptoms often get worse as a bird matures. My nephew had a pet turkey he was very fond of, and we kept it alive for a year, but eventually it got so bad that we had to euthanize it. (It would lose coordination and fall to the floor, and be so upset it would flap and kick and hurt itself.)
The only thing you can do is never breed from a strain that shows the disease, cull the parents as well as the affected birds, and buy from breeders who have made sure they don't have it.