Accept the disease. You can not change this reality, but you can manage the behavior.
Arguments are useless, and, in fact, make matters worse.
Allow as much freedom and independence as possible, while keeping safety and comfort in mind. Actions help when verbal communication may fail. Help the patient by demonstrating what you mean, or sometimes, by starting them in the activity. Assume that the person may understand and hear what you say even if they are confused. Do not say things to others in front of them as if they are deaf.