Research reported at the Alzheimer’s Association International Conference (AAIC) 2017 in London, England, highlighted the clinical value of amyloid-β PET scans, which detect the presence of amyloid-beta plaques in the brain – one of the hallmarks of Alzheimer’s disease. Studies also revealed an underutilization of amyloid-β PET imaging in clinical care, contributing to misdiagnosis of dementia.
Two studies at AAIC 2017 reported that brain PET imaging allows for more accurate detection or exclusion of Alzheimer’s in a larger proportion of individuals than standard clinical assessment supported by structural and metabolic imaging, and cerebrospinal fluid (CSF), and that use of amyloid PET scans may lead to a change in diagnosis in up to two-thirds of cases. A meta-analysis of data in a large population of participants found that brain amyloid PET scans led to a change in diagnosis in approximately 20 percent of these individuals.
Other PET-related research reported at AAIC 2017 included the following findings:
A survey of individuals with cognitive impairment and their caregivers found that more than 80 percent were receptive to undergoing a PET imaging study if it was recommended by their doctor, and clinicians would base decisions about future patient care on brain PET scan findings. Many study participants were frustrated by the lack of availability of brain amyloid PET scans in clinical practice. A separate analysis of Medicare claims data found that approximately 60 percent of dementia cases are missed in clinical practice, particularly cases of early dementia. Click here to read more about all of these studies.
“A negative brain PET scan indicating sparse to no amyloid plaques rules out Alzheimer’s disease as the cause of dementia symptoms. This makes it a valuable tool to clarify an uncertain or difficult diagnosis,” said James A. Hendrix, PhD, Alzheimer’s Association Director of Global Science Initiatives. “Misdiagnosis is costly to health systems, and expensive and distressing to persons with dementia and their families.
“Beyond the data reported at AAIC 2017, the IDEAS Study will provide further evidence to demonstrate the utility of amyloid PET imaging in a clinical setting,” said Hendrix. “A swift and accurate diagnosis has a huge impact on access to Alzheimer’s treatments, eligibility for research trials, plus much-needed support and information services.” The IDEAS Study is led by the Alzheimer’s Association and managed by the American College of Radiology and American College of Radiology Imaging Network.
Local Medical Community Involved in IDEAS Study
A few Dayton-area physicians participate as qualified dementia specialists for the IDEAS Study — including the Dayton Center for Neurological Disorders led by Neurologist Ken Pugar, D.O., and Valley Medical Primary Care, led by Meenaski Patel, M.D. PriMed physicians and University of Cincinnati physicians also participate. Kettering Medical Center is the only Dayton-area PET scanning facility that
participates in the IDEAS Study. Patient referrals are made only after extensive examination by physicians and where a diagnosis of Alzheimer’s is uncertain.
Participants must be Medicare beneficiaries referred by qualified dementia specialists who meet appropriate use criteria for amyloid PET (Johnson et al. 2013).
Specifically, patients must meet the following criteria:
- Cognitive complaint verified by objectively confirmed cognitive impairment
- Cause of cognitive impairment is uncertain after a comprehensive evaluation by a dementia expert, including general medical and neurological examination, mental status testing including standard measures of cognitive impairment (e.g., Mini Mental State Examination [MMSE] or Montreal Cognitive Assessment), laboratory testing for toxic-metabolic disturbances and structural neuroimaging (CT or MRI)
- Alzheimer’s disease is a diagnostic consideration
- Knowledge of amyloid PET status is expected to alter diagnosis and disease/patient management
Limited Access Leads to Underutilization of PET Scanning
While research supports the value of PET scans for clarifying a diagnosis of Alzheimer’s disease, Liana Apostolova, MD, of Indiana University School of Medicine in Indianapolis and colleagues presented a study at AAIC 2017 that indicates that limited access to PET imaging is proving frustrating to individuals and their caregivers, and it leads to continued frequent misdiagnoses of people who would benefit from early intervention.
The team surveyed 510 participants and caregivers (predominantly in the U.S.) to gauge their attitudes about PET imaging as a part of patient care. Between 85 percent and 91 percent of respondents indicated they were dissatisfied with the availability of PET scans, supported additional research on PET imaging and were willing to undergo PET scans if they were recommended by their physician.
Medicare Claims Frequently Misidentify Dementia
Carolyn Zhu, PhD, of Icahn School of Medicine at Mount Sinai in New York and colleagues analyzed data from 2,144 participants in the Washington Heights-Inwood Columbia Aging Project and found that Medicare claims frequently misidentified dementia cases. The sample included 1,689 individuals not diagnosed with dementia and 455 with a clinical diagnosis of dementia based on a rigorous clinical assessment performed at study enrollment. Medicare claims prior to study enrollment allowed for successful identification of 1808 subjects (85 percent), suggesting moderate agreement between claims data and subsequent clinical diagnoses. However, 281 subjects (62 percent) diagnosed with dementia at study enrollment were not identified as such based on prior treatment reported in Medicare claims. These people were younger and had better general health and cognitive function than those identified as having dementia based on Medicare claims.
More Funding is Needed
While the U.S. Congress has recently provided additional funding for Alzheimer’s research at the National Institutes of Health (NIH), the commitment falls far short of the need. In 2017, for every $100 the NIH spends on Alzheimer’s research, Medicare and Medicaid will spend $12,500 caring for those with the disease. Congress must continue its commitment to the fight against Alzheimer’s and other dementias by increasing funding for Alzheimer’s research by at least an additional $414 million in fiscal year 2018.
About Alzheimer’s Association International Conference (AAIC)
The Alzheimer’s Association International Conference (AAIC) is the world’s largest gathering of researchers from around the world focused on Alzheimer’s and other dementias. As a part of the Alzheimer’s Association’s research program, AAIC serves as a catalyst for generating new knowledge about dementia and fostering a vital, collegial research community.
AAIC 2017 home page: www.alz.org/aaic/