Alzheimer’s disease (AD) is a silent killer of brain and lives of world’s elderly people. It is the fourth leading cause of death among the older adults in the developed world. Named after Alois Alzheimer, the German physician who identified it in 1907, it remains elusive as to its cause and is resistive to treatment. It starts as a robber of memory and slowly erodes the intellectual and functional abilities leaving the patients bed-ridden and ultimately leads to death, mostly by pneumonia (infection of the lungs). It enormously affects the patients as well as the caregivers considering the long period of suffering (8-20 years).

Over the last few decades AD has dramatically changed from an obscure disorder to a major public health problem affecting millions of people worldwide. Besides the emotional and social issues at stake the economic costs of AD to society is massive. This disease is a major contributor to increasing health care, bankrupting families and draining more than US$100 billions from the US economy.

Age is a major risk factor: the longer one lives, the greater the possibility of getting AD (about 50 percent of Americans over 85 have AD). AD seldom occurs before the middle age in a clinically obvious form, and then the likelihood doubles exponentially every five years. Given the fact that the elderly are the fastest growing group in the world population AD is termed as the epidemics of the elderly. With no cure in sight this deadly disease is estimated to hold 37 millions in its grip by 2050.

In Asia, China's elderly population over 60 is projected to increase from 130 million in 2000 to 370 million in 2050, from 11% to 26% of the total population, with an annual rate of 3.2 %. The graying of the middle kingdom will not only cause demographic transformation but the economic and social challenges it poses will affect China's competitiveness in the global economy.

In addition to being the world's second most populous country, India has one of the largest populations of older adults. India’s 60-plus population (around 80 million) is increasing by 3 % annually and is likely to double over the next 25 years. Besides, a large section of the older population in India is illiterate and lives in rural areas which lack infrastructure. Due to lack of awareness of AD most patients/family members tend to ignore the symptoms of the disease as normal part of aging process. Clinical help is sought only after a drastic deterioration of patient’s health.

The pathway of Alzheimer's disease remains unknown, although a number of risk factors are apparent including a small percentage (5 - 10%) of getting it through familial inheritance. AD involves death of neurons in specific parts of brain. The brain shrinks (atrophy) in these parts and as a result mental functions associated with these areas are affected. Currently there is no treatment that can stop or reverse AD. The approved therapeutics targets the symptoms (loss of chemical messenger systems) not the probable cause (neuro-degeneration – loss of neurons).

Post-mortem examination of the brains of the people affected by AD showed two characteristic features: Amyloid plaques outside the cells and tangles inside the nerve cells. The pathway by which these two abnormal features are formed and affect the functioning of the cells is being investigated so that interventions can be developed to alter the course of the disease.

Apart from memory loss AD patients have other symptoms including loss of language skills, disorientation in space and time and inability to do familiar tasks. Physicians often use checklists of symptoms, and other behavioral assessment tools, to help them detect Alzheimer's. In addition, noninvasive neuro-imaging tools are increasingly used to understand the disease better.

Advances in sensitive imaging techniques to visualize the brain functions including X-ray computerized tomography (CT), Magnetic resonance imaging (MRI) and Positron Emission tomography (PET) have helped to diagnose malfunction in brain. CT scan uses a computer to reconstruct a three-dimensional view of the brain from separate x-ray images taken at different angles. The MRI scanner uses strong magnetic fields to create images. While MRI and CT scans provide structural information PET yields functional image of the brain. PET helps to monitor the level of chemical activity going on in different regions of the brain. By studying the parts of brain that are implicated in AD one can confirm the disease using PET imaging. PET scan is expensive and only a few centers (even in US) have access to these facilities. Recently in US medicare coverage has been expanded to avail PET for suspected AD cases.

With the explosion of knowledge during the past few decades on Alzheimer’s disease, the stage is set for a promising outlook in the distant horizon. The future builds upon the events and experiences of the past and present. Mankind, waging a constant battle against diseases, has conquered some of them with advances in science and technology. One day, we may be able to prevent or even cure this terrible disease, which robs our loved ones of their most precious faculty - their minds.  

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