Could the spouse of an Alzheimer's patient set up a spendthrift trust with his spouse's assets and serve as the trustee

spendthrift trust for Alzheimer's patient?: Could the spouse of an Alzheimer's patient set up a spendthrift trust with his spouse's assets and serve as the trustee? Would this then allow him to ensure the spouse will more likely have sufficient assets to pay for medical care and any other life necessities without being able to fritter the money away on nonsense--such as jewelry?
Can the Alzheimer's patient agree to such a trust (in the early stages of the disease) to protect that person from wasting his funds. (Alzheimer's patients are VERY attractive to scam artists of all sorts, but not all scammers are recognized as such and CAN get away with the ill-gotten funds in many cases.)