My father-in-law was diagnosed with it. Fortunately for everyone involved, 8 months later he died of a heart attack.
My mother-in-law is currently under long-term care for it. We lived with and cared for her until it started adversely impacting our health and she started needing specialized care. We were able to find a facility that specialized in dementia care. There have four wings that deal with various levels of the disease.