Alzheimer’s Disease: PreClinical
Changes on magnetic resonance imaging [MRI] may precede the diagnosis of Alzheimer disease by up to 10 years and any clinical symptoms by 4 years. Early diagnosis is important as there are several new possible treatments including some that can be started even before symptoms occur.
Tondelli, Manuela, Gordon K. Wilcock, Paolo Nichelli, Celeste A. De Jager, Mark Jenkinson, and Giovanna Zamboni. “Structural MRI Changes Detectable up to Ten Years before Clinical Alzheimer’s Disease.” Neurobiology of Aging 33, no. 4 (April 2012): 825.e25-825.e36. https://doi.org/10.1016/j.neurobiolaging.2011.05.018
Of the possible imaging biomarkers for Alzheimer’s disease that may be used to try to identify individuals before clinical symptoms appear, MRI is the only one that does not involve exposure of the patient to ionizing radiation.
Jack, Clifford R., David A. Bennett, Kaj Blennow, Maria C. Carrillo, Billy Dunn, Samantha Budd Haeberlein, David M. Holtzman, et al. “NIA-AA Research Framework: Toward a Biological Definition of Alzheimer’s Disease.” Alzheimer’s & Dementia 14, no. 4 (April 2018): 535–62. https://doi.org/10.1016/j.jalz.2018.02.018.
Adverse financial events as a preclinical disease marker:
Alzheimer disease and related dementias were associated with adverse financial events years prior to clinical diagnosis that become more prevalent after diagnosis.
Nicholas, Lauren Hersch, Kenneth M. Langa, Julie P. W. Bynum, and Joanne W. Hsu. “Financial Presentation of Alzheimer Disease and Related Dementias.” JAMA Internal Medicine, November 30, 2020. https://doi.org/10.1001/jamainternmed.2020.6432.