“I was very active, loved sports, loved doing things, and the mother of five boys,” she told the crowd at Fortune’s Most Powerful Women Summit in D.C.

The news triggered a painful journey of self-discovery.

“If you’re independent and strong and healthy and suddenly you’re not, something happens to your identity,” she said. “And you try to figure out ‘who am I,’ and ‘what am I worth.’” Depression followed. “It’s more difficult than most people think,” she says.

But today, Romney, now 68 and largely symptom-free, has decided to take a leadership role in helping to mitigate, even eliminate the devastating effects of neurological diseases. As the Global Ambassador of the Ann Romney Center for Neurologic Diseases at Brigham and Women’s Hospital in Boston, Romney has partnered with the same researchers who helped her work her way back to health.

It happened in 2012, “after the historic election when my husband lost,” she laughs. Romney was having a routine check-up with her MS doctor, Dr. Howard Weiner. “I was asking him, as I always do, what the newest research was,” she said.

Turns out, there was something to report. His research had led him to a potential breakthrough in treating Alzheimer’s disease; further, there were promising results from a Parkinson’s drug and a renewed belief that the work could make a difference with amyotrophic lateral sclerosis or ALS patients. “I said, ‘are you kidding me?’”

Without First Lady duties to attend to, she decided to throw her weight behind creating a center that would explore intersectional research regarding the brain. The center opened in 2014.

Collectively these three diseases, including brain tumors, affect 50 million people worldwide, with devastating impacts on their lives, their communities and the economy. And, with the exception of Parkinson’s, most disproportionately affect women. “Women need to get involved,” says Romney, who is also collaborating with Maria Shriver, who became an Alzheimer’s research advocate after her father was diagnosed with the disease. “[As women] we tackled breast cancer really well.”

The center at Brigham and Women Hospital — a teaching hospital and part of the Harvard Medical School system — helps break down the natural silos that form when researchers work separately. Romney says important clinical trials are imminent, including a long-awaited nasal vaccine for pre-symptomatic Alzheimer’s patients.

But when asked what she needs to further the work, Romney shifts immediately into management mode.

“Money,” she says, without hesitation. The National Institute of Health is not going to fund something this experimental. “Philanthropic dollars are the only way to do something new.”