Ron Petersen (Mayo Clinic) has been active in defining and studying MCI (1).
Ron has a theoretical framework based on assumed etiology, with which he predicts (2) that:
- single-domain amnestic MCI (aMCI), i.e., memory impairment only, will progress to pure AD (if not caused by depression);
- multi-domain amnestic MCI will progress to AD plus vascular dementia (if not caused by depression);
- non-amnestic MCI will progress to non-AD dementias.
Ron showed a graph on the slide "MCI: Conversion to Dementia" (3), which shows:
- 35 percent of non-ApoE4 carriers will progress to dementia in three years;
- 90+ percent of ApoE4 carriers will progress to dementia (still progressing at four years).
ADNI partners (and others) are researching biomarkers for earlier/better prediction of conversion (4-6). Various cerebrospinal fluid (CSF) biomarkers and changes in brain-region sizes from neuroimaging seem to have predictive power (7).
References:
1. Petersen, R. Mild Cognitive Impairment. CONTINUUM: Lifelong Learning in Neurology. Dementia. 13(2):15-38, April 2007. Abstract
2. Edited by Ronald C. Petersen. Mild Cognitive Impairment: Aging to Alzheimer's Disease. Oxford University Press, USA; first edition January 9, 2003.
3. Petersen, Ronald C. Mild Cognitive Impairment: The Current Status. Talk at 10th Annual Updates on Dementia conference, Stanford University, June 4, 2008.
4. Antecedent Biomarkers for the Early and Preclinical Detection of Alzheimer's Disease
5. ADNI: GWA Nearly Complete, Biomarker Analysis Update
6. ADNI: Mission Creep From Alzheimer Disease to Healthy Senior?
7. Beckett, Laurel, ADNI Biostatistics Core, director. Private communication.
View all comments by Scott Weikart