Loss of Smell Could Be Early Sign of Alzheimer’s

TUESDAY, Jan. 12 (HealthDay News) — New research in mice suggests that loss of smell could serve as an early indicator of Alzheimer’s disease.

People with Alzheimer’s are already known to suffer from loss of smell. But the new research pinpoints a direct link between development of amyloid plaques — the bits of gunk in the brain that cause Alzheimer’s disease — and a worsening sense of smell.

The findings are reported in the Jan. 13 issue of the Journal of Neuroscience.

Researchers found that the plaques first develop in the part of the mouse brain that’s devoted to the sense of smell. When tested, the mice with the plaques had to spend more time sniffing odors to remember them, and they had a hard time telling the difference between odors.

“What was striking in our study was that performance of the mouse in the olfactory behavior test was sensitive to even the smallest amount of amyloid presence in the brain as early as 3 months of age (equivalent to a young adult),” study co-author Daniel W. Wesson, of New York University School of Medicine and the Nathan S. Kline Institute for Psychiatric Research in Orangeburg, N.Y., said in a university news release.

“This is a revealing finding because, unlike a brain scan, a laboratory-designed olfactory test may be an inexpensive alternative to early diagnosis of Alzheimer’s,” Wesson said.

– Randy Dotinga

Hypertension Drugs May Cut Alzheimer’s Risk

By Bill Hendrick
WebMD Health News

Reviewed By Louise Chang, MD

Jan. 12, 2010 — Drugs commonly used to treat high blood pressure and heart disease may reduce the risk of dementia and Alzheimer’s disease, a new study suggests.

Boston University scientists, reporting in the journal BMJ, say a class of high blood pressure drugs called angiotensin receptor blockers is associated with a striking decrease in the risk of occurrence and progression of dementia.

The researchers, using information from a U.S. Department of Health System Veterans Affairs database of more than 5 million people, examined records of more than 800,000 predominantly male patients 65 or older.

The researchers compared the patients in groups that included those using an angiotensin receptor blocker (ARB); those using an ACE inhibitor called lisinopril (Prinivil, Zestril); and those using other blood pressure/heart disease medications (excluding statins).

Angiotensin receptor blockers include candesartan (Atacand), irbesartan (Avapro), losartan (Cozaar), and valsartan (Diovan).

There were no differences in average blood pressure among the three groups.

The patients taking an angiotensin receptor blocker had a 19% lower risk of developing dementia compared to those taking lisinopril and a 24% lower risk compared to use of other blood pressure/heart medications. People taking both an ACE inhibitor and an angiotensin receptor blocker, which both target the angiotensin system, had a 46% lower risk of dementia compared with those taking other medications.

The researchers also studied records of patients who already were suffering from dementia or Alzheimer’s. Those patients taking ARBs, the scientists report, had a lower risk of being admitted to a nursing home or dying. Those taking both an ARB and an ACE inhibitor had a 67% lower chance of being admitted to a nursing home.

The results suggest that ARBs might protect against developing Alzheimer’s disease and dementia, the researchers write.

“For those who already have dementia, use of ARBs might delay deterioration of brain function and help keep patients out of nursing homes,” says Benjamin Wolozin, MD, PhD, professor of pharmacology at Boston University and one of the study researchers. “The study is particularly interesting because we compared the effects of ARBs to other medications used for treating blood pressure or cardiovascular disease.”

The researchers write that they do not know exactly why ARBs might be so beneficial, but they believe the drugs may help prevent and reduce nerve cell injury from stroke or blood vessel damage.

The researchers say they’ve conducted the first large-scale study to investigate whether angiotensin receptor blockers reduce the risk of developing Alzheimer’s or dementia.

The findings of the study are “immense,” write Colleen J. Maxwell, PhD, and David B. Hogan, MD, of the University of Calgary in an accompanying editorial. “About 36 million people worldwide have a form of dementia such as Alzheimer’s disease,” they write. “If survival, prevention or treatment do not improve dramatically, this number could double over the next 20 years.”

However, they add, though the findings of the study are dramatic, further work is needed to verify the results.

Frequent Mental Lapses May Precede Alzheimer’s

By Steven Reinberg
HealthDay Reporter
Latest Alzheimers News

* Mental Lapses May Precede Alzheimer’s
* ‘Longevity’ Gene May Cut Dementia Risk
* Hypertension Drugs May Cut Alzheimer’s Risk
* Alzheimer’s Could Be Signaled by Loss of Smell
* Nutrient ‘Cocktail’ Appears to Improve Dementia
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MONDAY, Jan. 18 (HealthDay News) — Mental lapses among older adults occur more often among those developing Alzheimer’s disease than healthy elders, new research finds.

Excessive daytime sleepiness, staring into space and disorganized or illogical thinking are other mental fluctuations that often precede Alzheimer’s, say researchers from Washington University School of Medicine in St. Louis.

“For many years, people have jokingly attributed mental lapses, or incidents when the train of thought temporarily seems to jump its tracks, as ‘senior moments,’” said lead researcher Dr. James Galvin, an associate professor of neurology. “It has never been clear as to whether these lapses could lead to the development of Alzheimer’s disease.

“We demonstrate clearly, for the first time, that such episodes are more likely to occur in persons who are developing Alzheimer’s disease,” he said.

But this doesn’t mean that everyone who has a “senior moment” is on the verge of dementia, Galvin stressed.

“While these lapses or fluctuations don’t by themselves mean that you have Alzheimer’s disease, our results suggest that they are something your doctor needs to consider if he or she is evaluating you for problems with thinking and memory,” he said.

The study is published in the Jan. 19 issue of Neurology.

For the study, Galvin’s team collected data on 511 seniors, average age 78, with memory problems. The researchers tested these adults with standard thinking and memory tests and also interviewed family members about their relative’s daytime sleepiness, disorganized or illogical thinking, or episodes of staring into space for long periods. Three or four symptoms were seen in 12% of participants, indicating cognitive fluctuations.

People with those symptoms were 4.6 times more likely to be diagnosed with Alzheimer’s and to have more severe Alzheimer’s symptoms, Galvin’s group found. They also performed worse on thinking and memory tests than people without these lapses.

Among 216 people diagnosed with very mild or mild dementia, 25 had mental lapses, while only two of the 295 without dementia had the fluctuations.

These mental lapses are common in a type of dementia called dementia with Lewy bodies — the second most common cause of dementia after Alzheimer’s disease, Galvin said. “But until recently we really did not know how frequently they occurred in people with Alzheimer’s disease or what effect fluctuations might have on their thinking abilities,” he said.

Cognitive fluctuations occur in Alzheimer’s disease and can significantly affect clinical rating of the severity of dementia and performance on memory and thinking tests. Assessing these fluctuations should be considered in evaluating patients for cognitive disorders, Galvin said.

Experts had mixed views on the significance of the findings.

“It is commonly observed that some Alzheimer’s disease patients can go through stages where they have apparent episodes of lucidity, when they can perform at much higher levels on ‘good days,’” said Greg M. Cole, a neuroscientist at the Greater Los Angeles VA Healthcare System.

This suggests that the cellular and molecular machinery required for higher performance has not been entirely lost but is frequently suboptimal, he said. “I find this quite hopeful as it suggests therapeutics might evoke more of these good days or moments,” said Cole, who is also associate director of the Alzheimer’s Disease Research Center at the University of California Los Angeles David Geffen School of Medicine.

But another expert said the finding adds nothing new to the diagnosis of Alzheimer’s disease.

Once many of these fluctuations start happening, “you are well on your way to dementia,” said Dr. Gary Kennedy, director of geriatric psychiatry at Montefiore Medical Center in New York City.

The hope for improving the diagnosis and treatment of Alzheimer’s hinges on finding physical markers that indicate disease progression and the effectiveness of treatment, another expert said.

“The finding is a terrific ad for the need for biomarkers in Alzheimer’s disease,” said William Thies, vice president for medical and scientific affairs at the Alzheimer’s Association.

These mental fluctuations may be common, but are not an exact measurement of whether Alzheimer’s disease is present or how far it has progressed, he said.

“We would like something better, something that has more precision, less variation,” Thies said.