Most older adults have mixed brain pathologies

Last Updated: 2007-12-28 14:00:22 -0400 (Reuters Health)

NEW YORK (Reuters Health) – Results of a brain autopsy study indicate that most older community-dwelling adults, regardless of the presence or absence of clinical dementia, have significant brain pathology, usually multiple pathologies.

As part of the longitudinal Rush Memory and Aging Project, researchers evaluated the spectrum of neuropathology found in the brains of 141 older adults, with and without clinically evident dementia.

At the time of death, only 20 persons (14.2%) were free of acute or chronic brain abnormalities, Dr. Julie A. Schneider, from Rush University Medical Center, Chicago, and colleagues report in the December 11 issue of Neurology.

Most older persons with dementia (i.e., memory and other cognitive impairments) had more than one pathology in the brain causing the impairment, Dr. Schneider told Reuters Health.

"This most commonly was Alzheimer’s disease pathology and cerebral infarcts (strokes), followed by Alzheimer’s disease and Lewy body disease, a disease related to Parkinson’s disease," she said.

Older persons without dementia also frequently had brain pathology, most commonly Alzheimer’s disease pathology, but also multiple other pathologies including stroke and Lewy bodies, Dr. Schneider noted. Having more than one pathology in the brain significantly increased the likelihood that symptoms of dementia will be present.

"Older persons can often handle one pathology in their brain, but the burden of more than one pathology may tip them over the threshold of clinical dementia," Dr. Schneider said.

"Therefore, prevention of not only Alzheimer’s disease but these other pathologies, particularly stroke and those things that may increase the risk of stroke (i.e., hypertension, hyperlipidemia, cigarette smoking, obesity) are likely to significantly decrease the prevalence of dementia," she added.

Based on this study, write two neurologists in an accompanying editorial, "we may wish to maximize medical management of vascular risk factors in the growing elderly population, regardless of whether cognition is still normal or there are signs of overt dementia."

"And if, some day, there were preventive therapies for synuclein pathologies, those might be helpful in a broader group of at-risk subjects," suggest Drs. Carol F. Lippa of Drexel University, Philadelphia and David K. Knopman of Mayo Clinic, Rochester, Minnesota.

Neurology 2007;69:2193-2194, 2197-2204.