"The general standard is that employers should make reasonable accommodations for someone with a disability," said Janice Goodman, a labor lawyer who specializes in discrimination cases.
"But there are a number of factual issues that need to be considered. Can there be an accommodation for this person? It is different for a janitor than the president of a company," she said.
According to the Alzheimer's Association, early onset patients often lose their insurance coverage once they are unable to continue working. They are also often not yet eligible for Medicare or disability.
Earlier this month the Social Security Administration held hearings in Chicago to discuss expanding benefits for middle-aged people diagnosed with Alzheimer's disease and other forms of dementia.
"Individuals with early onset dementia can certainly apply for disability," said Mark Hinkle, a spokesman for the Social Security Administration. "We look at each case individually on a case-by-case basis. Whether or not someone will qualify will depend on the severity of their situation. We're working with the Alzheimer's Association on how to identify and help the most severe cases to get people the best care as soon as possible."
It is at work that many people first realize their diminishing mental capacity. Tasks that were once routine seem difficult and strange. Once-successful relationships with colleagues become strained when the diagnosed person struggles with his work.
Undiagnosed, Pat Van Dyke went through a series of demotions at a California-based sales company, unsure of why she had difficulty with tasks at which she once been proficient.
Over the course of several months, Van Dyke went from the executive assistant to the company's owner – managing several executive's schedules and regularly working with members of the staff -- to a receptionist, where she did little else but answer the phone.
"I started to make mistakes, I couldn't remember things, I couldn't do spreadsheets. I couldn't do anything without someone checking my work. No one wanted to work with me because I couldn't do anything. People assume you're not a good worker, that you don't care anymore, or that you're not trying," said Van Dyke, 55.
"I got a demotion and then I got another demotion. I tried to write things down, but I'd forget to look at my notes. My bosses were getting upset and the demoted me as low as they could," she said.
Once she received her diagnosis and learned she had early-onset Alzheimer's disease, she said her co-workers acted awkwardly around her.
"People don't understand what the disease is about. When you have cancer people are compassionate and understanding," Van Dyke said.
Van Dyke left her job nine months after receiving her diagnosis. She moved to Texas to live closer to one of her two adult children.
But for patients with young children, leaving work adds to the fear about how they will best be able to care for their kids.
"Often people are not financially prepared. The have dependents, sometimes they need money to pay for children who are ready to go college. Sometimes, in addition to caring for their kids they are also responsible for elderly parents," said Bluethmann from the Alzheimer's Association.
The association recommends young onset patients investigate early retirement and other financial planning options while still at work and make preparations with an attorney or financial planner.
For Diane Thornton, her diagnosis cut her family's income in half. Her children aged 14 and 17, she said, immediately felt the impact.
"We took a massive hit to our income. The kids stopped extracurriculars. We couldn't afford to pay for music lessons."
But, she says of her children, "they're incredibly resilient."
"We've been upfront about my diagnosis. They understand what is happening. I'm worried about them and they're worried about me. What scares me most is that I'll forget to keep worrying."