[A version of this item appears in: Dementia: the Latest Evidence Newsletter (RWHT), Volume 2 Issue 3, October 2011].
The process of developing Alzheimer’s Disease is known to begin years before the formal diagnosis of clinical dementia. The concept of Preclinical Alzheimer’s Disease is used to understand why senile plaques and neurofibrillary tangles may occur in the brains of people who still have normal cognitive function at the time of death. Some authors use the related concept of Asymptomatic Alzheimer’s Disease (ASYMAD) to reflect the possibility that different people with the same degree of “hallmark” pathologies may have different clinical profiles.
This systematic review examines recent advances in biomarker studies and the developing ability to detect the pathologic changes at work in Alzheimer’s Disease which are antecedent to symptoms of the illness, i.e. already at work in cognitively “normal” individuals. This review focuses on the studies of antecedent biomarkers for preclinical Alzheimer’s Disease. The ability to detect the presence of preclinical Alzheimer’s Disease may one day offer opportunities for intervention with disease-modifying therapies and widespread public health programmes. Quotation:
“The long preclinical phase has profound implications for Alzheimer’s Disease therapeutic strategies. Since potential intervention with disease-modifying therapies may provide the greatest chance of preserving normal cognition, it will be critical to identify individuals with preclinical Alzheimer’s Disease before the development of cognitive deficits and concomitant neuronal loss. Thus, there may be a paradigm shift in Alzheimer’s Disease from cure to prevention. The hope is that in the future, Alzheimer’s Disease will be managed in the way cardiovascular disease is handled now. Physicians will use lifestyle factors and diagnostic measures to define the risk of Alzheimer’s Disease in their patients, followed by manipulation of their diet, lifestyle, and medications to delay or prevent the symptomatic onset of this disease”.
Shim, YS. Morris, JC. (2011). Biomarkers predicting Alzheimer’s disease in cognitively normal aging. Journal of Clinical Neurology, June 2011, Vol.7(2), pp.60-8. (Click here to view the PubMed abstract).