Tracking an Assassin of Memory

By Catherine Arnst


Alzheimer's: Portrait of an Epidemic

By David Shenk

Doubleday -- 290pp -- $24.95

In the mid-1800s, few American intellectuals were more revered than Ralph Waldo Emerson. The philosopher was the bright center of a group that included Henry David Thoreau and Henry Wadsworth Longfellow. One of his famous essays, written when he was in his 50s, was on the subject of memory: "Without it, all life and thought are an unrelated succession. As gravity holds matter from flying into space, so memory gives stability to knowledge. It holds us to our family, to our friends. Hereby a home is possible; hereby only a new fact has value."

Sadly, within 20 years of writing those sentences, Emerson himself had no powers of memory left. He did not recognize his closest friends and could not understand what he read or follow a conversation. He had all the hallmarks of a disease that had not yet been named but had plagued mankind throughout history: Alzheimer's.

This illness of aging illustrates the truth of Emerson's essay. For Alzheimer's slowly and relentlessly destroys not only memories but all the cognitive processes by which people define themselves. And thanks to longer-than-ever life spans in Western countries, the incidence of Alzheimer's is inexorably rising--bringing both social and economic burdens. Currently about 4 million people in the U.S. have Alzheimer's, and the cost of their care is $114.4 billion annually. Because some 50% of people over the age of 85 develop the disease, the Alzheimer's Assn. predicts that, based on projected life expectancies, there will be 12 million sufferers nationwide by 2050.

There are plenty of books and other resources aimed at helping caregivers cope with the disease. Journalist David Shenk's contribution is more literary in nature. The Forgetting is a quirky mix of medical history, the voices of patients and their families, and accounts of the search for a cure. It includes case histories of such probable past victims as Emerson and Jonathan Swift, as well as current sufferers, such as former President Ronald Reagan. The book's structure is far from linear, but somehow, it works. Shenk makes the science understandable and recounts personal stories that are both moving and illuminating.

The disease was first identified in 1906 by a German doctor, Alois Alzheimer. Performing an autopsy on a female patient who died in her 50s after a long bout of dementia, the doctor discovered that the patient's brain was riddled with crusty brown clumps and weedy fibers. "Here was the evidence that [the patient] had not lost herself," writes Shenk. "Rather, her `self' was taken from her." Scientists have since learned that these plaques and tangles, as they are called, are made up of a sticky protein that slowly strangles the brain. The first line of attack is the region of the mind associated with short-term memory. But as the protein accumulates, the patient loses more and more knowledge and slowly regresses to an infant-like state, which ends in death. Interestingly, the social skill that lingers the longest is manners--many caregivers note that their charges may not know who they are, but still say "please" and "thank you." These common courtesies are some of the first lessons drilled into a child's memory and are thus among the last memories to be destroyed.

As he delves into the science, Shenk gives a fascinating account of what memories are made of. He tells the story of a Harvard University-trained neurosurgeon, William Beecher Scoville, who in 1953 removed a section of the hippocampus from a 27-year-old man who had suffered from violent seizures since childhood. The operation eliminated the seizures but produced a grisly side effect--the patient could never again form new memories. For the rest of his long life, he could not learn a new face, name, or fact. The case revolutionized the study of the mind by revealing the role of the hippocampus in consolidating immediate thoughts into long-term memories. It also shed new light on Alzheimer's because its victims exhibit a similar form of the same problem. Scientists realized that when a patient can't locate his or her car keys, it's not so much that a memory has been lost as that it was never formed in the first place.

Shenk's exploration of the science of memory is the most satisfying part of the book. Far less so is his breathless account of the race for a cure. He details the many meetings of Alzheimer's researchers, the breakthroughs in understanding how the plaques are formed, and the debate between two different camps over whether these plaques are the cause of the disease or a symptom. But his overly dramatic telling occludes the fact that therapeutic progress has been incremental at best. The most promising new drug--a vaccine that has cleared away plaques in mice--is years away from being proven effective in humans.

In the end, it is Shenk's interviews with patients and caregivers that stand out. The voices of people recently diagnosed--and their struggles to maintain their dignity--are heartbreaking. The most moving story is that of Morris Friedell, a college professor in Santa Barbara, Calif., who was diagnosed with Alzheimer's when he was 59. Friedell is carefully chronicling his decline in the hope that it might help researchers. He is also trying to prove that rehabilitation is possible, at least in the early stages of the disease. Friedell has even presented posters explaining his research at scientific meetings. But he writes that in the last of Shenk's many conversations with the professor, a year after their first encounter, Friedell "asked me if we'd ever spoken before today."

Senior Writer Arnst covers medicine.

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