The latest news on Alzheimer's disease seems promising: new genes have been identified that are associated with the late-onset form of the disease. With this discovery, our understanding of the risks and, ultimately, of the causes of Alzheimer's disease for the vast majority of its sufferers has taken a step forward. But what does this mean, practically speaking, for someone today?
As a geriatric psychiatrist and the director of a large memory center in Miami, this question is posed to me daily. I see individuals with Alzheimer's disease across every stage of illness and with impairments in every sphere of life. It's a devastating disorder that unfolds over an average of eight to ten years, but its roots in the brain begin years before symptoms present. Up until recently, however, there have been no practical ways to detect the disease at that early stage. This may be why existing treatments, both approved and experimental, have been limited in their success. It's like trying to put out a bonfire with a small fire extinguisher. In its earliest stages, this disease might just be manageable with several existing experimental treatment approaches, including antibodies and vaccines that prime the immune system to rid the brain of what we believe is one of the main culprits - a toxic protein called beta-amyloid. In fact, the good news about previous vaccine research is that if you're a mouse with Alzheimer's disease (and yes, these do exist!), we can cure you. The bad news, of course, is that we're not mice.
Something remarkable, however, has started to happen. Our center was contacted recently about participating in a clinical trial for a new vaccine against Alzheimer's disease for individuals so early in its course that symptoms are hardly detectable. I indicated our enthusiasm to be a site for the study, but expressed my concern that we don't have the ability, as clinicians, to accurately detect the disease at that stage, short of obtaining a brain biopsy. I was informed, however, that the diagnosis would not come from me as a doctor, but from a new type of brain scan that can identify the telltale build-up of the toxic protein. With this new scan, which is hopefully moving closer to final approval by the Food and Drug Administration, it will be like conducting a virtual brain biopsy. History has now turned a page, and we are on the verge of having accurate and commercially available early detection for Alzheimer's disease. In a related development to this, the National Institute on Aging and the Alzheimer's Association have released new guidelines that identify an initial stage of illness where biological signs of the disorder in the brain, blood and spinal fluid herald its impending arrival before symptoms even appear.
This news would be all the more wonderful if we had a cure to go along with the diagnosis. Existing medications can sometimes improve or stabilize symptoms modestly but not slow down the inexorable and tragic course of the illness. Experimental treatments, if they work, are years away from approval. So we are left with the very real and approaching possibility in the next few years that we will be able to go to a local imaging center and have a brain scan that makes a likely diagnosis of Alzheimer's disease before symptoms present, but with little or nothing to do to prevent disease onset and progression. As one of the doctors who will face the wave of these individuals, I worry about the immense fear and despair many will face. Ironically, the uncertainty of the diagnosis in its earliest stages preserves some vestige of hope for many individuals that maybe it's not actually Alzheimer's disease. But this uncertainly will soon disappear. It's a blessing in search of a cure.
So I welcome the news about new genetic discoveries. We're getting closer to fully understanding the causes of this growing epidemic among our elderly that is staring all of us in the face. But we still have a long way to go, and this should demand (and I hope our legislators are listening closely) more concerted and better-funded efforts to not only provide optimal care while we're searching for a cure, but to launch a war on Alzheimer's disease given the staggering toll in human suffering, not to mention the annual price tag for our economy that is now estimated to be over $180 billion.