The simple answer is no or not without a court order. The fundamental principle behind giving another control over your affairs is that you know what you are doing. The legal term is that you have “capacity” to sign the agreement. Capacity keeps a person from being abused when they do not know what they are doing. Thus, a power of attorney signed by someone who has had an incident that keeps them from having capacity is not valid.
You can, however, get a court oder appointing a guardian. This process requires that you meet certain conditions and file the right documents. Hiring an attorney is strongly recommended at this point.
Let me know if you have any questions or need my help.