Gene Wilder's widow on what it's like to care for someone with Alzheimer's Karen Wilder addresses the toll caring for someone with Alzheimer's can take.

 -- In an exclusive essay for ABC News, Karen Wilder opens up about her 35-year marriage to the late actor and activist Gene Wilder. The “Young Frankenstein” star died last year at the age of 83, after battling Alzheimer's disease in the final years of his life. Wilder discusses some of the trials and tribulations caregivers or spouses can experience when caring for someone living with the debilitating disease. These are her words:

I never pictured myself marrying a movie star. I also never saw myself spending years of my life taking care of one. But I’ve done both. Love was the reason for the first. Alzheimer’s disease, the second.

I met Gene Wilder in 1989. He was preparing to shoot a movie called “See No Evil, Hear No Evil,” in which the character he played was deaf. Though I grew up in very small town in Idaho, where it was a big deal if you had indoor plumbing, I had been working in New York City for over twenty years by that point as a speech pathologist with the hearing impaired. As he always did when he took on a role, Gene wanted to understand his character. He showed up at my office one day in search of my professional advice.

We formed a powerful bond. At the time, Gene was married to Gilda Radner, who was in the final stages of ovarian cancer. After Gilda’s death, Gene sought me out again. We married a year later and, for more than twenty years, we were one of the happiest couples I knew. We traveled to France and played tennis together (three sets in a single afternoon). When I signed up for tap dancing lessons, Gene joined me. We set up side-by-side easels in the garden painting watercolors. At night, we danced together on a floor we’d built, under the stars -- The Waltz, Salsa, Cha Cha and Tango.

The first signs of trouble were small. Always the kindest, most tender man (if a fly landed on him, he waited for the fly to leave), suddenly I saw Gene lashing out at our grandson. His perception of objects and their distance from him became so faulty that on a bike ride together, he thought we were going to crash into some trees many feet away from us. Once, at a party with friends, when the subject of “Young Frankenstein” came up, he couldn’t think of the name of the movie and had to act it out instead.

When we finally got him tested and the diagnosis came back, it was Alzheimer’s. Unlike other diagnoses, even some cancers, this one offers not even a shred of hope for survival. The synapses of his brain were getting tangled and the result would be a steady and terrible progression of losses -- memory of course, but also motor control, to the point where eventually his body would simply forget how to swallow or breathe.

My husband took the news with grief, of course, but also astonishing grace. I watched his disintegration each moment of each day for six years. One day, I saw him struggle with the ties on his drawstring pants. That night, I took the drawstrings out. Then his wrist was bleeding from the failed effort of trying to take off his watch. I put his watch away.

I was determined to keep Gene with me –- in California and, finally, at the home we’d made together in Connecticut. We still managed to have some good times and to laugh, even at the ravages of the disease that was killing him.

One day, when he fell on the patio and couldn’t get up, I maneuvered him over to the edge of our pool and floated him to the other side, where there were steps and a railing to assist him. Another time, after struggling for twenty minutes trying to pull himself up, he looked out as if he was addressing the audience at the Belasco Theater, a place he knew well, and said in his best Gene Wilder voice, "Just a minute folks. I’ll be right back."

But there’s another particularly cruel aspect to the disease of Alzheimer’s, because in addition to destroying – piece by piece – the one who’s stricken with it, it ravages the life of the person caring for its victims. In our case, I was that person.

I am grateful that I knew to reach out for help from the Alzheimer’s Association. When I did, I learned some alarming statistics from them. One in three seniors dies with Alzheimer’s or another dementia. That means, if a mature couple invites two couples over for dinner, one of the couples could face Alzheimer’s.

Then came the biggest shocker: 40 percent of Alzheimer's caregivers die before the patient according to a study done by Stanford Medicine -- not from disease, but from the sheer physical, spiritual and emotional toll of caring for a loved one with Alzheimer’s.

Gene died fifteen months ago. I was in the bed next to him when he took his last breaths. By that point, it had been days since he’d spoken. But on that last night, he looked me straight in the eye and said, three times over, "I trust you."

So, I have a responsibility, I think. Neither my love, nor science, could save my husband’s life. But it’s my most profound hope that through research and awareness, others may be spared the experience that killed Gene -- and could have killed me, too. of Earlier this month, The Gates Foundation announced the largest gift ever presented to the cause of Alzheimer’s research: a commitment of $100 million aimed at eradicating the disease within our lifetime. I am profoundly grateful that this crisis, viewed for too long as insoluble, is receiving funding for the dedicated scientific community, with the goal of early diagnosis and ultimately a cure. It was in this vein that I allowed the use of my husband’s character of Willy Wonka to be used in the “Pure Imagination Project,” a new video campaign to bring greater awareness about Alzheimer’s and encourage each of us to do our part.

But let’s not forget that other killer -- the silent one that takes its victim even before the disintegration of brain cells does its own dirty work. I am speaking of the crisis that can kill the once-healthy loved spouses, siblings, friends and adult children of Alzheimer’s patients, who devote almost every waking hour of their lives (and also the nights) to caring for a person they love, but who may no longer recognize them.

I am grateful that Gene never forgot who I was. But many caregivers of Alzheimer’s patients are less fortunate.

Every year, Alzheimer’s disease costs our nation an estimated $259 billion, according to the Alzheimer's Association. At this hopeful moment, when there is more momentum than ever towards finding a cure and treatments, let’s also remember the desperate need of caregivers.

It is a strange, sad irony that so often, in the territory of a disease that robs an individual of memory, caregivers are often the forgotten. Without them, those with Alzheimer’s could not get through the day, or die -- as my husband did -- with dignity, surrounded by love.