Towards Improving Prediction of Progression to Dementia: Emerging Evidence for Role F-18 FDG PET in Developing Countries

Mild cognitive impairment (MCI) represents a stage of cognition between normal to dementia, and is considered to represent a higher risk of progression to Alzheimer's Disease Dementia (AD) at a rate that ranges from 10 to 30% per year. With increasing awareness and rising burden of dementia in developing countries like India, persons with mild cognitive problems seeking help in clinical practice is rising, and there is a need to develop research evidence for identifying reliable predictive methods for the context of India. Advances in research suggest that several predictive factors for developing dementia are emerging, based on biomarkers. The incorporation of biomarkers into dementia research has not only enhanced the prediction of development of AD from MCI but has also helped in investigating disease modifying agents that will prevent the progression of MCI to dementia. Thus, differentiating patients who are likely to progress to dementia, from those who are unlikely to do so, is critical in the context of management and future therapies. Recently, the A/T/N biomarker classification in AD has been proposed which advocates the use of plasma, CSF, and neuroimaging biomarkers for diagnosis. Although amyloid imaging is a considered to be an important biomarker in predicting future cognitive decline, its lack of availability and potential cost in Low- and Middle-income countries like India are major limiting factors. Therefore, the study of the utility of a more available and accessible alternative biomarker in the form of 18-fluorodeoxyglucose positron emission tomography (18 FDG PET) imaging of the brain is important for developing countries like India.