Alzheimer's Signs | Symptoms of Alzheimer’s

Disease accounts for up to 80% of cases of dementia

Consumer Reports on Health: May 2012

In this Office Visit column, Marvin Lipman, M.D., Consumer Reports' chief medical adviser and medical editor, discusses early warning signs of Alzheimer's disease.

“Is it Alzheimer’s?” A concerned daughter silently mouthed that question after a lengthy office visit during which she had described her mother’s increasing loss of short-term memory and occasional erratic behavior.

The focus of this attention was an 85-year-old retired college professor, a seemingly healthy long-term patient of mine who, in all the years she had been coming to see me for routine examinations and an occasional infection, had provided me with few or no clues that she might be slowly developing a disorder that affects 5.5 million Americans.

She systematically fended off each of her daughter’s accusations: “If you had eight grandchildren, you’d get them mixed up, too. The reason I showed up at the wrong house for your birthday was that it was dark and the street signs were hard to read. The pot boiled over and ruined the kitchen floor because the timer didn’t ring.”

Her physical exam was completely normal, as it always had been, except that she asked what her blood pressure was on several occasions during and after the exam. She could name only 11 animals over a 60-second time span (with normal recall she should have been able to name at least 14). As part of a mini-cognitive assessment, she could recall only one of three unrelated nouns mentioned to her before being asked to draw a clock with hands at 11:10. She also drew it wrong, indicating 10 minutes before 11:00.

Minding the mimics

I answered the daughter’s question with a qualified “yes.” But to be more certain I had to rule out several potentially reversible Alzheimer look-alikes. Low levels of vitamin B12, folate, or thyroid hormone could produce the cognitive problems commonly seen with Alzheimer’s disease, but tests showed her levels were normal. She didn’t have the urinary incontinence and gait abnormalities seen in normal-pressure hydrocephalus.

Her normal blood pressure, absence of obvious heart disease, and lack of a smoking history made multiple mini-strokes unlikely. She wasn’t on any mind-clouding sleep medication, tranquilizers, or antihistamine-like drugs. And she had no symptoms of depression. Therefore, she fulfilled the criteria for Alzheimer’s disease, which accounts for up to 80 percent of cases of dementia among the elderly.

The greatest risk factor for dementia is age. By the eighth decade of life the prevalence of dementia is about 5 percent, increasing to 37 percent in nonagenarians. But recent research has challenged the notion that dementia is a disease of only the very old. A study in the British Medical Journal in January 2012 clearly showed that cognitive decline in those destined to develop Alzheimer’s disease can begin as early as the fifth decade of life. This is reminiscent of the results of autopsy studies done on soldiers killed in the Korean conflict, which showed plaque buildup in the coronary arteries of men in their 20s, decades before heart disease typically becomes symptomatic.

Prevention and treatment

Definitive steps to prevent Alzheimer’s disease have yet to be identified. But since type 2 diabetes and many of the risk factors for heart disease have been linked to the eventual development of dementia, it makes sense to eat right and stay fit. Intellectual activities and social contacts probably don’t do much good, though they may be helpful in other ways.

What intrigued me most about our patient was the fact that her dementia—which must have been developing over a few years—was a complete surprise to me. As is common with Alzheimer’s, she had not complained about any cognitive problems. More often than not, it’s someone close—a concerned son, daughter, or spouse—who notices something is wrong and seeks a diagnosis. In contrast, people with non-Alzheimer’s age-related memory loss constantly complain about forgetting names, but their cognitive and other reasoning abilities remain intact.

With the diagnosis of the retired professor on firm ground following a confirmatory consultation with a local neuropsychiatrist, combined treatment with donepezil (Aricept and generic) and memantine (Namenda) was started. Only time will tell if the drugs will slow the progression of the disease to the optimistic 50 percent reported in 2008 in the journal Alzheimer Disease & Associated Disorders.