Advances in brain imaging can expedite research and diagnosis in Alzheimer's disease

October 11, 2011

Alzheimer's disease (AD) is a common problem that is becoming progressively burdensome throughout the world. A new supplement to the Journal of Alzheimer's Disease, Imaging the Alzheimer Brain, clearly shows that multiple imaging systems are now available to help understand, diagnose, and treat the disease.

"Alzheimer's disease is now seen as a continuum that is influenced by factors early in life, including genetics and education," according to Guest Editor J. Wesson Ashford, MD, PhD, Clinical Professor and Senior Research Scientist at the Stanford/VA Alzheimer Center, Palo Alto, CA. "Conceptualizing the continuum of AD with advanced imaging technology will provide a greater understanding of the disease, and help advance diagnosis and the quest for prevention and treatment."

The supplement features both reviews of the basic concepts of in the context of AD, the latest developments in imaging, and various discussions and perspectives of the problems of the field and promising directions. It provides in-depth insights into: pathology and pathophysiological bases of AD; structural and imaging; metabolism, amyloid plaques, and neurofibrillary tangles in vascular co-morbidity and AD; current advances in functional for detecting AD; electromagnetic ; ; ; and longitudinal neuroimaging measures.

Investigators have used imaging to track some of the earliest changes associated with the predisposition to AD. In their paper, "Alzheimer's Prevention Initiative: A Plan to Accelerate the Evaluation of Presymptomatic Treatments," a group of scientists proposes to evaluate investigational treatments in healthy people who, based on their age and , are at the highest imminent risk of developing symptomatic AD. "It currently takes too many average healthy people, too much money, and too many years to evaluate the range of promising presymptomatic treatments using clinical endpoints," says lead author Eric M. Raiman, of the Banner Alzheimer's Institute and the University of Arizona. The project will use brain imaging studies, cerebrospinal fluid biomarkers, and cognitive measures to evaluate AD-modifying treatments earlier than is otherwise possible and to determine the extent to which the treatment's brain imaging and other biomarker effects predict a clinical benefit, among other outcomes.

Dr. Ashford comments that "even when imaging data are not applied to the management of individual patients, these data have the potential to assist in evaluating other components of care and diagnosis. To the extent that imaging can more sensitively measure brain integrity than existing techniques, novel treatments may be discovered because beneficial effects of treatments are not detectable with other methods."

Two articles in the supplement offer intriguing insights into the relationship between cortical thinning and AD. In "Relationship Between CSF Biomarkers of Alzheimer's Disease and Rates of Regional Cortical Thinning in ADNI Data," investigators from the Department of Veterans Affairs Medical Center, San Francisco, the University of California and the Hospital of the University of Pennsylvania tested the association between rates of regional brain cortex thinning and reduced amyloid (Ab1-42) and higher tau concentrations. Using data from the Alzheimer's Disease Neuroimaging Initiative, they found that these biomarkers were associated with increased rates of brain tissue loss, and that the patterns varied across the healthy elderly and the mildly cognitively impaired. "The finding of faster progression of brain atrophy in the presence of lower Ab1-42 levels and higher p-tau levels supports the hypothesis that they are measures of early AD pathology," says lead author Duygu Tosun.

It's known that the presence of an ApoE e4 (e4+) allele increases the risk of developing AD. There is an adverse relationship between e4+ status and brain structure and function in mild cognitive impairment; the presence of an e2 allele may be protective. In "Presence of ApoE e4 Allele Associated with Thinner Frontal Cortex in Middle Age," investigators examined whether the brain cortex thinning is the result of the disease, or a pre-existing endophenotype. Drawing on imaging data from a large national sample, the study examined the influence of ApoE on regional brain thickness and structure. The presence of the e4+ demonstrated significantly thinner cortex in the frontal areas, and may explain susceptibility to AD. The presence of the e2 allele was related to thicker cortex, suggesting a protective role.

In all, 31 papers discuss the advances in numerous imaging methodologies that are being used to increase our understanding of the pathophysiological basis of AD and drive us toward new therapies for this complex brain disorder. "Ultimately, the prospects for neuroimaging to enhance clinical care in Alzheimer's disease are bright as researchers collaborate and clinicians become informed about innovations and advances," says George Perry, PhD, Editor-in-Chief, Journal of Alzheimer's Disease, and Dean and Professor, College of Sciences, University of Texas at San Antonio.

Related Stories

Recommended for you

Antibody found that fight MERS coronavirus

July 28, 2015

(Medical Xpress)—An international team of researchers has found a MERS neutralizing antibody—a discovery that could perhaps lead to a treatment for people infected with the virus. In their paper published in Proceedings ...

Experimental MERS vaccine shows promise in animal studies

July 28, 2015

A two-step regimen of experimental vaccines against Middle East respiratory syndrome (MERS) prompted immune responses in mice and rhesus macaques, report National Institutes of Health scientists who designed the vaccines. ...

Can social isolation fuel epidemics?

July 21, 2015

Conventional wisdom has it that the more people stay within their own social groups and avoid others, the less likely it is small disease outbreaks turn into full-blown epidemics. But the conventional wisdom is wrong, according ...

Lack of knowledge on animal disease leaves humans at risk

July 20, 2015

Researchers from the University of Sydney have painted the most detailed picture to date of major infectious diseases shared between wildlife and livestock, and found a huge gap in knowledge about diseases which could spread ...

IBD genetically similar in Europeans and non-Europeans

July 20, 2015

The first genetic study of inflammatory bowel disease (IBD) to include individuals from diverse populations has shown that the regions of the genome underlying the disease are consistent around the world. This study, conducted ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.