As baby boomers move into old age and live longer, the potential number of Alzheimer's sufferers in the U.S. may reach record levels. CBS News Chief Medical Correspondent Dr. Jon LaPook follows an Alzheimer's patient and her caregiver husband for 10 years in an unprecedented report that shows future sufferers and their caregivers what they may face. "For Better or for Worse" will be broadcast on 60 Minutes on Sunday, April 22 at 7:00 p.m. ET/PT on CBS.The Alzheimer's Association told 60 Minutes it is unaware of any other video study of this length documenting the progression of the disease, which has no cure.  LaPook chronicles a loving husband's increasing burden as he cares for the woman he loves as she slowly disappears in front of his eyes. The story of Mike and Carol Daly of Staten Island, NY,  is a sweet and sad journey from better to worse.In her first interview, Carol's memory is slipping, but she knows how old she is; she is active and can still do her job at the bank. In just three years, she no longer knows her age and her lack of concentration makes it impossible for her to read or watch movies. As LaPook records her mental and physical decline, he also reports Mike's parallel emotional erosion.The Alzheimer's Association warns of the dangerous stress caring for a patient can cause. The upbeat can-do attitude Mike displays early in the report fades toward the end, coinciding with Carol's descent into complete helplessness. "I'm dying. I really think I am. The stress – they thought I had a heart attack to begin with," he tells LaPook, "They wanted to put me in the hospital. I can't go to the hospital. What do I do with Carol?"Eventually, Mike has to hire someone to help him take care of Carol. It was another expense adding to the expense of this disease, which costs the Dalys $40,000 per year. That cost is for home care.  Nursing home care, inevitable in many cases, is much more.Alzheimer's forced  Mike and Carol to switch roles, says Mike. He tells LaPook he does the household chores Carol once did and now, he must care for her, too.  When LaPook says to Mike, "That's not what you signed up for," he replies, "Yes I did. "When we took our oath, it's for better or for worse."