Greg O'Brien is the author of "On Pluto: Inside the Mind of Alzheimer's" and a patient-advocate for the Alzheimer's Association. He is featured in the NOVA film “Can Alzheimer’s Be Stopped?"

A neuron of an Alzheimer’s disease sufferer. (Linnea Rundgren/New Scientist)

On a recent flight from San Francisco back to Boston, I found myself seated between my 28-year-old daughter, Colleen, and the emergency hatch. When the attendant asked if I could perform the duties, I shrugged and simply said I was afraid of heights. I forgot about the confusion. I forgot why doctors don’t let me travel alone anymore. Alzheimer’s will do that.

Somewhere over Chicago, I had to go to the bathroom. My mind told me the bathroom door was immediately to my right — all I had to do was to pull on the lever — so I grabbed for it. It took Colleen screaming for me to realize that my hand was on the emergency exit door. The crew later told me never to sit in an exit row again.    

My life has become a race for survival against Alzheimer’s, and I’m not the only one. More than 5 million Americans suffer from this demon of a disease, a number expected to double in the next 20 years as my fellow baby boomers reach the age of its onset. Treating Alzheimer’s in the United States now costs more than $200 billion a year. By 2050, that could surpass $1 trillion.

So as a longtime investigative journalist, I’ve been chronicling my experience with the disease to help others know what to expect. Recently, I also welcomed a PBS “Nova” film crew into my home to document my struggle, in hopes that it can help add to the body of knowledge and research that may one day lead to a cure.

Boomers and our families will soon find out that Alzheimer’s is not just a disease of the elderly: Experts say it can take 20 to 25 years to run its serpentine course. The brain pathology, doctors observe, can begin at 40, with neurological symptoms and inflammation that develop before other visible signs. I know the front line well. Alzheimer’s stole my maternal grandfather, my mother and my paternal uncle. And before my father’s death, he also was diagnosed with dementia.

Now it’s my turn.

In 2009, at age 59, I was diagnosed with early-onset Alzheimer’s. A battery of clinical tests, brain scans and a SPECT scan confirmed the diagnosis, which doctors say was accelerated by two serious head traumas that “unmasked a disease in the making.” (I also carry the Alzheimer’s marker gene APOE-4.) I had already been having some memory loss and difficulty multi-tasking before the first head injury, caused by a bicycle accident. After that, I sought medical help.

The official finding came two weeks after I was diagnosed with prostate cancer, which, after consulting with my family and my doctors, I’ve decided not to treat. My plan is for cancer to kill me before my Alzheimer’s symptoms get too awful. I don’t want to take my wife and children to that end place of Alzheimer’s, which we’ve already seen up close with other relatives. My family now is dealing with the new “me.” But the disease has also brought us closer together, forcing us to unite and work more to find meaning in the face of loss. It’s scary for them, but they are pushing back on the fear, and I am proud of them.

After a brief pity party, I pulled myself up to deal with Alzheimer’s. I reverted to mental muscle memory and began to report on my demise, detailing 1,000 pages of notes that became “On Pluto: Inside the Mind of Alzheimer’s.” My book is a blueprint of strategies, faith and humor; a day-to-day focus on living with Alzheimer’s, not dying of it; a hope that all is not lost when it appears to be.

For baby boomers, I feel like the canary in the coal mine while scientists search for a cure. I fear the day when I put my fingers on the keyboard and don’t know how to write anymore. That’s the day I will give up, heading out, as I put it in the book, to the desolation of Pluto.

Mornings for me are always the same: in disarray. At first light, I must focus on the basic questions, the who, what, where, when, why and how of life. (If only rebooting my brain before tossing the covers and organizing the scattered files of my mind was as easy as rebooting my faithful MacBook Pro when it starts running slowly.) I do so out of instinct, but there’s always the depression, fear and angst to maneuver, too. And that’s just on the way to the bathroom, where — on doctors’s advice — I’ve begun labeling the toothpaste, liquid soap and rubbing alcohol. I have attempted often to brush my teeth with liquid soap and on two occasions gargled briefly with rubbing alcohol.

My mind used to be my best friend, but now I see no chance for reconciliation. Doctors say that I’m working off a “cognitive reserve,” a backup tank of inherited intellect, but they warn that the tank will go dry soon, as it did with my mother.

Daily medications serve to slow down the progression of the disease and to help control the rage on days when 60 percent of my short-term memory is gone in 30 seconds — days when I hurl the phone across the room, a perfect strike to the sink, because in the moment I don’t remember what number to dial. Or when I smash the lawn sprinkler against an oak tree in the back yard because I can’t recall how it works, or when I push open the flaming-hot glass door to the wood stove in the family room bare-handed to stoke the fire because my mind told me it was a good idea, resulting in a second-degree burn. Or simply when I cry privately, the tears of a little boy, because I fear that I’m alone, nobody cares and the innings are beginning to fade.

Years ago, I thought I was Clark Kent, Superman, an award-winning journalist who feared nothing. But lately, I feel more like a baffled Jimmy Olsen. And on days of muddle, more like Mr. Magoo — the wispy cartoon character whose poor vision was exacerbated by his stubborn refusal to acknowledge a problem. Or perhaps like a codfish landed on the dock. As the saying goes, a fish rots from the head down.

By documenting Alzheimer’s, I’m getting even with it. But I cannot do it alone, and I do not know how much time I have left. If we are going to win this fight, we need to grapple with the scope of the problem and try harder to cure it. Not for me, but for my children, and for you and your children, and for my whole generation and their families and loved ones, who will face this prowling demon soon enough.

Read more:

Keeping mentally active doesn’t stave off Alzheimer’s

How curiosity changes our brains

Doctors don’t actually know how often you should see them