"On the basis of a simple neuroimaging study, we can now predict which patients with Parkinson's disease will experience long-term cognitive decline or develop dementia in the future."
Alzheimer's Reading Room
A method of classifying brain atrophy patterns in Alzheimer's disease patients using MRIs can also detect cognitive decline in Parkinson's disease, according to a new study by researchers from the Perelman School of Medicine at the University of Pennsylvania.
Researchers also found that higher baseline Alzheimer's patterns of atrophy predicted long-term cognitive decline in cognitively normal Parkinson's patients.
The study is published online in Brain.
|Subscribe to the Alzheimer's Reading Room|
This research raises the possibility that both Alzheimer's disease and Parkinson's disease pathology contribute to cognitive decline in Parkinson's disease. Researchers are still uncertain whether the neurodegeneration seen in these patients is caused by primary Parkinson's disease pathology, Alzheimer's pathology, a combination of the two, or is a form of compensation.
As biomarkers for Alzheimer's and Parkinson's disease continue to emerge, the researchers suggest at least an overlap in regions undergoing neurodegeneration with cognitive decline, and point to the Spatial Pattern of Abnormalities for Recognition of Alzheimer's disease (SPARE-AD) classification system to detect brain atrophy in Parkinson's disease, to detect patients at imminent risk of cognitive decline before clinically identifiable symptoms emerge.
Around 80 percent of Parkinson's patients become demented over the course of the illness.
Some patients experience cognitive impairment relatively soon after the disease strikes, while others won't experience dementia until the very end of their disease.
Duration and severity of the disease and advanced age are risk factors for dementia, while nearly 20 percent of patients never have dementia. Over half of Parkinson's patients with dementia have significant signs of Alzheimer's disease-related plaques and neurofribrillary tangles on autopsy, and similar brain regions, such as the hippocampus and medial temporal lobe, have been reported to be affected in both diseases.
The Penn research team applied a pattern classification individual-based score, the SPARE-AD score, to a cross-sectional cohort of 84 Parkinson's patients including patients with dementia, mild cognitive impairment and no dementia.
In the cross-sectional analyses, the SPARE-AD score correlated to cognitive impairment across all groups. From this group, 59 Parkinson's patients without dementia were followed for an additional two years. Researchers determined that a higher baseline SPARE-AD score predicted worsening cognitive performance over time, even in those patients with normal cognition at baseline.
In addition to Dr. Weintraub, the research team included Nicole Dietz, John Duda, David Wolk, Jimit Doshi, Sharon Xie, Christos Davatzikos, Christopher Clark, and Andrew Siderowf, representing the Penn Udall Center for Parkinson's Research and the Perelman School of Medicine's departments of Psychiatry, Neurology, Radiology, Biostatistics and Epidemiology. Dr. Weintraub and Dr. Duda are also with Philadelphia Veterans Affairs Medical Center.
The study was funded by grants from the National Institutes of Health's National Institute of Neurological Disorders and Strokes and National Institute of Aging, as well as a grant awarded by Department of Health of the Commonwealth of Pennsylvania from the Tobacco Master Settlement Agreement.
Penn's Perelman School of Medicine is currently ranked #2 in U.S. News & World Report's survey of research-oriented medical schools and among the top 10 schools for primary care. The School is consistently among the nation's top recipients of funding from the National Institutes of Health, with $507.6 million awarded in the 2010 fiscal year.
Penn Medicine is committed to improving lives and health through a variety of community-based programs and activities. In fiscal year 2010, Penn Medicine provided $788 million to benefit our community.
More Insight and Advice for Caregivers
- How Alzheimer's Destroys the Brain -- Video
- Test Your Memory for Alzheimer's (5 Best Self Assessment Tests)
- What is Alzheimer's Disease?
- What is Dementia?
- What’s the Difference Between Alzheimer’s Disease and Dementia
- Communicating in Alzheimer's World
- How the Loss of Memory Works in Alzheimer’s Disease, and How Understanding This Could Help You
- Learning How to Communicate with Someone Suffering From Alzheimer's Disease
- Alzheimer's World -- Trying to Reconnect with Someone Suffering from Alzheimer's Disease
- Does the Combination of Aricept and Namenda Help Slow the Rate of Decline in Alzheimer's Patients
- About the Alzheimer's Reading Room
Original content Bob DeMarco, the Alzheimer's Reading Room