Alzheimer's Disease Center
University of California, Davis
The Family Connection
Winter/Spring 1998
UCD ADC Research Examines Progression of
Alzheimer’s Disease
Mary N. Haan, MPH, DrPH
Researchers at the UCD Alzheimer’s Center (ADC) recently completed a study looking at differences among patients in three groups--those diagnosed with 1) Alzheimer’s disease only, 2) Alzheimer’s disease and vascular dementia and 3) Alzheimer’s disease with Lewy bodies. Vascular dementia refers to the concept that vascular disease (such as stroke) may cause cerebral injury and impair cognitive function. Lewy bodies are small round structures found within the nerve cell bodies of the substantia nigra in the brain stem and in the cerebral cortex. This is a relatively recently described diagnosis, and patients with Lewy bodies often have symptoms similar to Parkinson’s disease and Lewy bodies are found in Parkinson’s patients.
For these three groups of patients researchers also looked at other symptoms including hallucinations, delusions and extrapyramidal signs. Extrapyramidal signs, also called EPS, are ratings on movement, gait and facial expression (please define) and are evaluated by a neurologist at the clinic visit. It is thought that the presence of these signs can provide useful information in diagnosing the type of dementia. The presence of hallucinations or delusions was also identified at the clinic visit by a neuropsychologist.
This study was unique from other studies at the Alzheimer’s Center in that all of the patients included were those who had died and an autopsy had been performed. An autopsy is beneficial because it is the most accurate method that researchers have to determine the type of dementia.
Alzheimer’s disease (AD) is the most common dementia in people aged 50 and older. Among patients with AD there are many differences in diagnosis, management and progression of Alzheimer’s disease, and these differences are not well-understood. The purpose of this study was to examine how the cognitive and functional abilities of patients are affected by the presence of hallucinations, delusions and extrapyramidal signs. The researchers also looked at differences in how long the patients survived based upon the type of dementia and the presence of these other symptoms.
A total of 169 patients were included in this study. Seventy-one percent of the patients had AD only, 10.1% had AD with vascular disease, and 19% had AD with Lewy bodies. The researchers found that patients with only Alzheimer’s disease had more severe disease and were less able to function than the patients with AD and vascular disease or those with AD and Lewy bodies. They also looked at differences in survival among these three groups. The researchers found that patients with AD and vascular dementia did not survive as long as patients in the other two groups. The study also showed that those patients with delusions combined with other symptoms (such as hallucinations or EPS) did not live as long while patients with only one of these symptoms did not show any difference in survival.
This study shows just one of the many ways that researchers at the UCD Alzheimer’s Center are attempting to further their understanding of Alzheimer’s disease. The results of this study will also be useful to health care professionals in developing the best strategies for managing Alzheimer’s disease for patients with different kinds of symptoms.