Meryl Comer has written a book called “Slow Dancing with a Stranger,” in which she deals frankly about life with her husband, Harvey Gralnick, who has Alzheimer’s disease. (Michael S. Williamson/The Washington Post)

Meryl Comer’s husband vanished more than a decade ago. Yet she has remained at his side, caring for him night and day as he drifted into the darkness of Alzheimer’s disease.

The story of how Comer, an Emmy Award-winning former broadcast journalist who lives in Kensington, Md., became just as much a victim of Alzheimer’s disease as her husband is unusual but not unique — which is why she has pushed to make it public.

In what is both a public-service campaign and an impassioned confessional, Comer has written a book about the ordeal that she and her husband, who had been a top researcher at the National Institutes of Health, have endured since being diagnosed with early onset Alzheimer’s 13 years ago.

In “Slow Dancing With a Stranger,” Comer offers an unflinching and intimate account about what it means to surrender one’s career to care for a stricken loved one and conveys a sense of passion and even frustration with a society that she believes has been slow to acknowledge the spread of Alzheimer’s disease or make adequate provisions to tend to its caregivers. It’s a love story without a happy ending, because the ending for Alzheimer’s patients can seem more like endless twilight. And it’s a call to arms for caregivers such as Comer.

“Do you know what it’s like to wake up every day knowing that whatever you do, it’s not going to help?” Comer, whose husband is receiving hospice care in their home, said in an interview last week. “I wanted a book that’s honest about what caregivers and families are facing. I want to shake up the status quo.”

More than 5 million people in the United States have been diagnosed with Alzheimer’s, and the number is expected to rise as the country’s population ages. The disease is incurable, progressive and destroys regions of the brain that are vital to cognition and memory. After it destroys a person’s essence — his or her identity — the disease can take the person’s life.

But Comer also focused on what the disease means for caregivers — studies show that caregivers usually are women — who are the collateral victims of Alzheimer’s disease, she said.

A report this year from the Alzheimer’s Association said that 15.5 million people were providing care for family members or friends with Alzheimer’s. Female caregivers outnumbered men by more than 2 to 1, with more than twice as many women as men – 11 percent vs. 5 percent — giving up formal employment entirely.

“It’s like secondhand smoke,” Comer said. “It tears families apart.”

In interviews and her book, Comer talks about the humiliation and stigma that accompany the disease, the awkward intimacies that arise when one tends to a spouse who has been reduced to child-like dependence, and the terror that erupts when patients lash out in fear and confusion, sometimes violently, at those closest to them.

She talks about how her hypervigilance — sometimes out of concern for her husband’s well-being, sometimes for hers — gave her symptoms like those of post-traumatic stress disorder. And she talks about the crises of doubt that make her sometimes ask why she has stuck around, why she has not put her husband in a facility and moved on. It is a question friends asked at times, often with a tone of criticism.

“Even I didn’t realize the nightmare until I read the book. At first, I was mad at her. My first reaction was, ‘How can you live this way?’ ” said a friend, Lisa Kirk Colburn, a documentary filmmaker who lives in Montecito, Calif. “Her capacity to love and care is beyond anything I’ve known. . . . And she’s been criticized for it. And I’m one of those who in the beginning didn’t understand what she’s doing.”

In the 1980s, Comer specialized in business news and its intersection with public policy, appearing on “It’s Your Business” and co-anchoring “Nation’s Business Today” on ESPN. She also worked for the “Ten O’Clock News” on Metromedia.

Comer’s husband, Harvey Gralnick, was chief of hematology and oncology at NIH, where he had been employed since the 1960s. He was a highly regarded expert on Von Willebrand disease, a hereditary disorder that causes bleeding because of a defect in a protein that enables blood clotting.

The couple met through a neighbor. Comer was divorced, the single mother of a 5-year-old boy. Gralnick had been married twice and had a son of his own from his first marriage. They married in October 1979.

When Alzheimer’s took hold, Gralnick was a fit 56-year-old — he ran six miles a day — who dressed impeccably, wearing the latest fashions beneath his lab coat, and he indulged his taste for fine food and wine while attending international conferences. He taught himself French using Foreign Service tapes and zipped to and from work in a canary yellow Porsche.

For a time, he was able to mask his symptoms behind his reputation as a brilliant if eccentric scientist. But then signs of cognitive impairment emerged: He faltered when colleagues asked for his opinion and confused vitamin K with potassium, whose chemical symbol is K.

More serious lapses followed. He wrecked his prized automobile, unable to remember how to shift into drive. He became lost when he left the house. He bumbled through a speech in front of colleagues that he was unable to finish.

Most troubling, Gralnick — at 6-feet-2 and 185 pounds — became prone to violent outbursts directed at Comer. To protect herself, she installed convex mirrors on the walls of their home so she could see around corners.

As his condition worsened, Comer, too, gave up her career — and, she adds with a note of bitterness, her “prime.”

In her blunt-talking manner, she acknowledged that she did so not entirely out of devotion but because doctors told her more than once, wrongly, that the progress of her husband’s disease would not be long.

Finances, too, were a factor. It was almost impossible to find care that she felt would be satisfactory for her husband and yet affordable. Her burden intensified even further when her mother, too, developed Alzheimer’s; her mother now shares the same home with Comer and her husband.

A glimpse of the way forward came in 2005, when the Alzheimer’s Association asked her to testify before a congressional Alzheimer’s caucus. But she also felt she had to rein in her emotions to focus on policy.

Then, in 2006, she went public in a big way, appearing on camera again, this time as the subject of a profile on Jim Lehrer’s “PBS NewsHour” that gave viewers an intimate view into Comer’s life as a caregiver.

George Vradenburg, a co-founder with Comer of the nonprofit group USAgainstAlzheimer’s, said he hopes that Comer’s book — whose proceeds will benefit research — stirs conversation about a disease many prefer not to think about.

“I hope America gets mad,’’ Vradenburg said Friday. “Why we aren’t getting mad is in part because it’s invisible. And in part, it’s associated with aging — ‘Oh, they lived a long life, and they have to die some way, anyway. So what?’ ”