Can you write, pass and enforce a law that stipulates that families provide for the care of an elderly or disabled member of the family? What would that care include? Would it mean providing in-home care, paying for a nursing home? Would it mean visiting or providing social interactions with the individual? These questions may seem startling. Perhaps you are saying "Of course! The government should protect the elderly and guarantee they are properly cared for." Perhaps you feel the government should not require one person to care for another. There could be a whole spectrum of responses between those two positions.
It turns out that a number of states in the US and a number of countries around the world have passed laws addressing the need for the care of the elderly or disabled. China, for example, has passed a law requiring adult children to visit their elderly parents and a woman has been required to visit her mother more as a result. Alternately, France has taken a different approach by supporting the care givers and providing respite care and in-home services, particularly for families caring for individuals with Alzheimer's.
For the most part, the laws surrounding elder care or care of the disabled do not specifically identify Alzheimer's or other forms of dementia. A study which evaluated the laws in the European countries, found brought this to light even as it identified the laws of each participant country. The countries are listed on the right and it is worth taking a peak into their individual summaries.
The US has elder care laws that are focused estate planning, elder abuse and neglect. However, as far as I know, neither the Federal government nor the State govements have implemented a law requiring regular visits.