Alzheimer's disease (AD) is a public health crisis with as many as two-thirds of elders with AD and half of elders with mild cognitive impairment (MCI), a prodromal phase of early AD, going undiagnosed in the community. Early diagnosis of Alzheimer’s disease is critical to managing the crisis. In support of early identification, in January 2011, the Centers for Medicare & Medicaid Service’s (CMS) Annual Wellness Visit issued a cognitive screening mandate, in which all CMS beneficiaries must undergo cognitive screening during their annual primary care wellness visit (see Figure 1). However, major obstacles limit primary care provider detection of early AD including insufficient time to properly assess cognition and a lack of appropriate screening tools to identify “at risk” elders.
Figure 1. Early Detection Initiative and Annual Wellness Visit Screening
One possible feature of early cognitive changes or impairment is a subjective cognitive decline (SCD) or when someone reports concern regarding a change in cognition. Prior evidence, including work from this initiative, suggests that SCD may represent the earliest manifestation of AD pathology. One, SCD is one diagnostic feature of the prodromal phase of AD (i.e., MCI). Two, an anatomical basis for SCD is supported by evidence of gray and white matter changes in normal older adults with a complaint. Three, SCD is associated with neuropathological, neuroimaging, and CSF markers of AD and is also related to an individual’s cognitive trajectory and diagnostic conversion from MCI to dementia (see Figure 2).
Figure 2. SCD Relates to Diagnostic Conversion to Dementia
However, key aspects of SCD are not fully understood and limit the implementation of a reliable and valid set of SCD questions in the primary care setting for early identification purposes. There is no gold standard by which to assess SCD. One focus of this initiative is to examine the nature of SCD by identifying specific SCD items that best measure this construct. Once SCD questions are identified, development of a brief, cost-effective, reliable, and valid tool is possible. This tool will be freely available and easy to implement for detection of individuals at risk for MCI and dementia in the community.
- Katherine Gifford, PsyD / Assistant Professor of Neurology at Vanderbilt University Medical Center
- Angela Jefferson, PhD / Professor of Neurology at Vanderbilt University Medical Center
- Timothy Hohman, PhD / Assistant Professor of Neurology at Vanderbilt University Medical Center
- Susan Bell, MBBS, MSCI / Assistant Professor of Medicine at Vanderbilt University Medical Center
- Ty Abel, MD, PhD / Assistant Professor of Pathology, Microbiology, and Immunology at Vanderbilt University Medical Center
- Rich Jones, PhD /Associate Professor of Psychiatry & Human Behavior; Associate Professor of Neurology at Brown University
- David Libon, PhD / Professor of Neurology at Drexel University
- Rhoda Au, PhD / Professor of Neurology at Boston University
Rabin A. Smart M, Crane K, Amariglio E, Berman M, Boada M, Buckley F, Chételat G, Dubois B, Ellis A, Gifford A, Jefferson L, Jessen F, Katz J, Lipton B, Luck T, Maruff P, Mielke M, Molinuevo L, Naeem F F, Perrotin A, Petersen C, Rami L, Reisberg B, Rentz M, Riedel-Heller G, Risacher L, Rodriguez O, Sachdev S, Saykin J, Slavin J, Snitz E, Sperling A, Tandetnik C, Van der Flier M, Wagner M, Wolfsgruber S, Sikkes A. Subjective Cognitive Decline in Older Adults: An Overview of Self-Report Measures Used Across 19 International Research Studies Journal of Alzheimer’s Disease. 2015 Sep 24;48(48). S63-S86. PMID: 26402085 [PubMed] PMCID: PMC4617342
Gifford KA, Liu D, Damon SM, Chapman WG, Romano Iii RR, Samuels LR, Lu Z, Jefferson AL. Subjective memory complaint only relates to verbal episodic memory performance in mild cognitive impairment. Journal of Alzheimer's disease : JAD. 44(44). 309-18. PMID: 25281602 [PubMed] PMCID: PMC4351870
Gifford KA, Liu D, Carmona H, Lu Z, Romano R, Tripodis Y, Martin B, Kowall N, Jefferson AL. Inclusion of an informant yields strong associations between cognitive complaint and longitudinal cognitive outcomes in non-demented elders. Journal of Alzheimer's disease : JAD. 43(43). 121-32. PMID: 25061054 [PubMed] PMCID: PMC4314962
Gifford KA, Liu D, Hohman TJ, Xu M, Han X, Romano RR, Fritzsche LR, Abel T, Jefferson AL. A Mutual Self- and Informant-Report of Cognitive Complaint Correlates with Neuropathological Outcomes in Mild Cognitive Impairment. PloS one. 10(10). e0141831. PMID: 26539829 [PubMed] PMCID: PMC4634952
Gifford KA, Liu D, Lu Z, Tripodis Y, Cantwell NG, Palmisano J, Kowall N, Jefferson AL. The source of cognitive complaints predicts diagnostic conversion differentially among nondemented older adults. Alzheimer's & dementia : the journal of the Alzheimer's Association. 2014 May;10(10). 319-27. PMID: 23871264 [PubMed] PMCID: PMC4064681