An estimated 5.3 million Americans have Alzheimer’s disease, and over 5 million of them are age 65 or older. Nearly two-thirds of those with the disease are women, and older Hispanics and African-Americans are more likely than non-Hispanic white people to have Alzheimer’s disease. Incidence of Alzheimer’s is expected to grow steadily as the over-65 demographic increases, with over 7 million Americans projected to have the disease by 2025.
Diagnosing Alzheimer’s disease is not an exact science. Various types of medical imaging and cognitive tests are used, and as there is currently no specific and accurate test that can definitively diagnose the disease in its early stages. However, one type of medical imaging may offer new hope for early diagnosis.
Why Does Early Detection Matter?
Unfortunately, many drugs that appeared promising for treatment of Alzheimer’s disease have not helped that much in real-world scenarios. If there were a way to diagnose Alzheimer’s early, or to accurately predict who would come down with it, researchers could work on preventing cognitive decline in the first place, rather than trying to help people recover from cognitive problems once they become evident. There’s no guarantee that early detection will lead to such a treatment, but it would give scientists more options, since treating Alzheimer’s after it has become evident in terms of cognitive decline has proven difficult.
A New Medical Imaging Study Involving Arterial Spin Labeling
Research from Switzerland and the Netherlands in 2014 found that differences in blood flow to a part of the brain called the posterior cingulate cortex were predictive of cognitive decline in people with normal cognitive functioning. One hundred forty-eight participants underwent MRI imaging using arterial spin labeling as well as neurocognitive tests at the beginning of the study and underwent neurocognitive tests again 18 months later.
At that time, the earlier scans of those whose test performance indicated “deteriorating cognitive function” were examined and found to show low blood flow to the posterior cingulate cortex. Scans of both groups were then compared to scans of people over age 65 with known cognitive decline, a group whose scans also showed low blood flow to the posterior cingulate cortex. In other words, low blood flow in that area of the brain was evident before neurocognitive testing indicated cognitive decline.
Arterial spin labeling is a technique that does not involve contrast dye as many types of computed tomography scans do. Rather, researchers can magnetically tag water protons that circulate in the blood so that they show up on MRI scans. This type of medical imaging is less expensive than positron emission tomography (PET) scanning, and less invasive than using injected contrast dyes.
Could MRI Preclude Need for Lumbar Puncture?
A 2012 study from the University of Pennsylvania found that strategic use of medical imaging could in some cases prevent the necessity of lumbar puncture in diagnosing Alzheimer’s disease. This study involved nearly 200 participants, all of whom had been diagnosed with dementia that could have been either Alzheimer’s disease or another type of dementia called frontotemporal lobar degeneration (FTLD).
When researchers used MRI scans to predict the ratio of biomarkers of FTLD (tau) and Alzheimer’s disease (beta amyloid), they were able to make diagnoses that were just as accurate as lumbar puncture in identifying the type of dementia the patient had. So not only can medical imaging help predict who will suffer cognitive decline, it can also be used to help determine whether someone has Alzheimer’s or another type of dementia.
Accuracy, Specificity Needed for Addressing Alzheimer’s Early
Researchers hope that by developing methods of identifying brain patterns indicative of Alzheimer’s disease before cognitive deficits are evident, they may be able to develop treatments that slow cognitive decline. Drugs given to people with Alzheimer’s who already show cognitive decline have not worked that well, and it’s possible that treatments to prevent decline in the first place will help in keeping people’s brains healthy as they age.
SteleRAD’s Board-certified medical imaging specialists have over four decades of experience in every type of medical imaging for diagnosis and interventional therapies. SteleRAD has an established team of Neuroradiologists that often work with patients with Alzheimer’s disease.
Dr. Michael DiGiorgio is one of SteleRAD’s Neuroradiology specialists. Dr. DiGiorgio received the “Mary P. Weiderman” Award for excellence in Physiology, and has authored numerous works. Dr, Shawn Fibkins is also a Neuroradiology Specialist with SteleRAD. Dr. Fibkins also specializes in Pediatric Radiology. To learn more about Dr. DiGiorgio, Dr. Fibkins, and the rest of the SteleRAD neuroradiology team – click here.
The expertise of SteleRAD’s radiologists is available to medical imaging centers, hospitals, and physicians’ facilities in South Florida. If you’d like to know more, call us at 954-358-5250 or contact us online at any time.