Download Cognitive Issues in Aging

Key Researcher
Anne Murray, MD, is a geriatrician, internist, and epidemiologist specializing in dementia. She
conducts research in the epidemiology of dementia in patients with kidney disease, anemia, and
diabetes. She enjoys teaching and is the Associate Fellowship Director of the Geriatric
Fellowship at HCMC, which trains future geriatricians.
Dementia is a progressive deterioration of the mind due to disease or damage to the brain. It is
described in degrees of cognitive (mental) impairment, with minor memory problems at the low
end of the spectrum to severe cognitive symptoms leading to loss of ability to perform daily
functions at the high end. Alzheimer’s disease and vascular dementia, (or dementia from blood
vessel damage and strokes), and Parkinson’s disease are leading causes. Researchers estimate
that between four and five million people in the US suffer from dementia. Dementia’s onset is
usually gradual, but the mental deterioration caused by its progression is devastating to the
individual and his family.
Anne Murray, MD, MSc, has been working with dementia patients and researching the
epidemiology of dementia for more than 20 years. She was involved in one of the first major
studies on dementia in East Boston, Massachusetts, which showed that 45 to 50 percent of
persons over 85 years suffer from some degree of dementia.
Today she works with researchers at the Chronic Disease Research Group and Berman Center
divisions of MMRF to study risk factors and outcomes for dementia. Most recently, she has
focused her research on how common cognitive impairment is among patients with kidney
disease or diabetes. Her work has demonstrated that hemodialysis patients have about three times
the risk of developing dementia compared to the general population. About 70 percent of
hemodialysis patients have moderate to severe cognitive impairment.
Dr. Murray’s work has shown that kidney hemodialysis often causes severe temporary cognitive
impairment during dialysis, with apparent recovery after each dialysis session, which over time
may contribute to dementia. She suspects the impairment stems from a rapid drop of blood
volume going to the brain, and brain swelling as a dialysis patient’s blood and waste products are
removed from the body. This blood flow hypothesis is supported by the fact that blood pressure
in the brain drops during dialysis, the incidence of stroke is higher during dialysis, and that
stroke is four times more common in dialysis patients than in the general population.
Dr. Murray is pursuing a research project using a device called a trans-cranial Doppler to
measure cerebral blood flow velocity in the main artery of the brain during dialysis, while also
measuring cognitive function. She hopes this will give her a clearer picture of the impact of
blood flow changes on the brain during dialysis.
She is also a coinvestigator for the National Institute of Aging-sponsored ACCORD (Action to
Control Cardiovascular Risk in Diabetes) and MIND (Memory IN Diabetes) clinical trial. This
study addresses the risk of cognitive decline and brain MRI changes, in addition to
cardiovascular disease faced by people with Type 2 (non-insulin dependent) diabetes. Initial
results from this study indicate that patients with chronically high blood sugars are at somewhat
greater risk for cognitive impairment.
Dr. Murray is also an investigator with the National Institutes of Health sponsored United States
Renal Data System Coordinating Center at MMRF. She conducts annual analysis of geriatric
renal-related diseases in the US for their Annual Data Report. Her contributions include
measuring the national prevalence and incidence of dementia and physical disability in chronic
kidney disease and dialysis patients. This year her findings show that at the time of starting
dialysis, approximately nine percent of patients were already unable to walk, and within one year
an additional 12 percent could no longer walk.
Dr. Murray plans to continue her dementia research with the goal of gaining a better
understanding of the complex ways that kidney disease and diabetes increase the risk of
dementia and disability, and discovering ways to prevent its development.