Alzheimer’s disease (AD)
Ibrahim B. Syed, Clinical Professor and Director of Nuclear Medicine Sciences, Division of Cardio-vascular Medicine, University of Louisville School of Medicine, Louisville, Kentucky, USA
Alzheimer’s disease or AD, is an irreversible, progressive brain disorder that slowly destroys memory and thinking skills and, eventually, the ability to carry out the simplest tasks. In most people with the disease—those with the late-onset type—symptoms first appear in their mid-60s. Early-onset Alzheimer’s occurs between a person’s 30s and mid-60s and is very rare. Alzheimer’s disease is the most common cause of dementia among older adults. 1
Alzheimer’s disease is a form of dementia. Although all Alzheimer’s patients have dementia, not all dementia patients have Alzheimer’s disease. The Alzheimer’s Association defines Alzheimer’s disease as “an irreversible, progressive brain disease that slowly destroys memory and thinking skills, eventually even the ability to carry out the simplest tasks.” Alzheimer’s is a fatal disease, ending inevitably in death. 2
The disease is named after Dr. Alois Alzheimer. In 1906, Dr. Alzheimer noticed changes in the brain tissue of a woman who had died of an unusual mental illness. Her symptoms included memory loss, language problems, and unpredictable behavior. After she died, he examined her brain and found many abnormal clumps (now called amyloid plaques) and tangled bundles of fibers (now called neurofibrillary, or tau, tangles) 1.
He correctly hypothesized that these abnormal deposits were responsible for the patient’s loss of memory and other cognitive problems.
These plaques and tangles in the brain are still considered some of the main features of Alzheimer’s disease. Another feature is the loss of connections between nerve cells (neurons) in the brain. Neurons transmit messages between different parts of the brain, and from the brain to muscles and organs in the body. Many other complex brain changes are thought to play a role in Alzheimer’s, too.
This damage initially appears to take place in the hippocampus, the part of the brain essential in forming memories. As neurons die, additional parts of the brain are affected. By the final stage of Alzheimer’s, damage is widespread, and brain tissue has shrunk significantly.
How Many Americans Have Alzheimer’s Disease?
Estimates vary, but experts suggest that more than 5 million Americans may have Alzheimer’s. Unless the disease can be effectively treated or prevented, the number of people with it will increase significantly if current population trends continue. This is because increasing age is the most important known risk factor for Alzheimer’s disease. In 2010, some 4.7 million people of 65 years of age and older were living with Alzheimer’s disease in the US. The 2013 statistical report from the Alzheimer’s Association gives a proportion of the population affected – just over a tenth of people in the over-65 age group have the disease in the US. In the over-85s, the proportion goes up to about a third. The Alzheimer’s Association says it accounts for between 60% and 80% of all cases of dementia 3.
Incidence of Alzheimer’s disease in India
In India, more than 4 million people have some form of dementia. Worldwide, at least 44 million people are living with dementia, making the disease a global health crisis that must be addressed. 4.
In the state of Kerala Among the 1066 eligible participants who were cognitively normal at baseline, 104 developed dementia (98 with AD) over a follow-up period of 8.1 years. The incidence rates per 1000 person-years for AD was 11.67 for those aged ?55 years and higher for those aged ?65 years (15.54). In those aged ?65 years, the world age standardized incidence rate, was 9.19 per 1000 person-years. Incidence rate of AD increased significantly and proportionately with increasing age. These are the first AD incidence rates to be reported from southern India. The incidence rates appear to be much higher than that reported from rural north India, comparable with that reported from China, and marginally lower than that reported from the western world. 5
What Does Alzheimer’s Disease Look Like?
Memory problems are typically one of the first signs of Alzheimer’s, though initial symptoms may vary from person to person. A decline in other aspects of thinking, such as finding the right words, vision/spatial issues, and impaired reasoning or judgment, may also signal the very early stages of Alzheimer’s disease. Mild cognitive impairment (MCI) is a condition that can be an early sign of Alzheimer’s, but not everyone with MCI will develop the disease.
People with Alzheimer’s have trouble doing everyday things like driving a car, cooking a meal, or paying bills. They may ask the same questions over and over, get lost easily, lose things or put them in odd places, and find even simple things confusing. As the disease progresses, some people become worried, angry, or violent.
How Long Can a Person Live with Alzheimer’s Disease?
The time from diagnosis to death varies—as little as 3 or 4 years if the person is older than 80 when diagnosed, to as long as 10 or more years if the person is younger.
Alzheimer’s disease is currently ranked as the sixth leading cause of death in the United States, but recent estimates indicate that the disorder may rank third, just behind heart disease and cancer, as a cause of death for older people.
Although treatment can help manage symptoms in some people, currently there is no cure for this devastating disease. 1
To this day, Alzheimer’s can only be diagnosed with 100 percent accuracy through an autopsy that reveals the presence of the characteristic plaques and tangles. However, a comprehensive examination and good workup do provide a reliable diagnosis with greater than 90 percent accuracy.
Abnormal deposits of specific proteins inside the brain disrupt normal brain function and cause the cognitive and functional problems typically associated with AD. Eventually, as the deposits spread throughout the brain, brain tissue starts dying, which leads to further cognitive impairment. The resulting brain shrinkage can be seen in CT scans and MRIs. Current research is focused on trying to determine what causes these deposits and is looking for ways to prevent or reverse them before they cause permanent brain damage. 2
Here’s what Alzheimer’s is not 2:
A natural part of the aging process
Something you get from using deodorant or cooking in aluminum pans
Inevitable if you live long enough
Although certain familial forms of Alzheimer’s Disease do run in families, these forms are extremely rare, accounting for less than 5 percent of all cases. So just because your mother or your brother got Alzheimer’s Disease doesn’t automatically mean that you’re going to get it as well.
No test can predict whether you’ll get Alzheimer’s disease unless you have the very rare inherited form of Alzheimer’s. A blood test exists that can tell you whether you have a certain form of a cholesterol-carrying protein associated with a higher incidence of Alzheimer’s disease, but that’s all that it can tell you. The test can’t tell you whether you’ll actually develop the condition because at least 50 percent of the people who have the risk factor never actually get AD.
For ethical reasons, healthcare professionals advise against taking this blood test or undergoing other genetic testing because they want to spare their patients unnecessary worry about something that’ll probably never happen even if the tests do come out positive. They also recommend against testing because if a person does find that he or she has inherited the gene or the risk factor, this information may negatively impact the person’s ability to get health insurance and long-term care coverage.
Fig. 1. CT scan of a Normal brain on the left and brain with Alzheimer’s Disease on the right. 6
Fig. 2. Comparison of a normal aged brain (left) and the brain of a person with Alzheimer’s (right). Differential characteristics are pointed out. 7.
Fig. 3. Brain atrophy in severe Alzheimer’s 7.
Fig. 4. Nuclear Medicine scans that illustrate the differences in three brains: a person with a healthy brain, left, one with mild cognitive impairment, center, and one with Alzheimer’s disease, right.8.
Fig. 5. A normal brain is on the left side and a brain with Alzheimer’s disease on the right side 9.
Like all types of dementia, Alzheimer’s is caused by brain cell death. It is a neurodegenerative disease, which means there is progressive brain cell death that happens over a course of time. The total brain size shrinks with Alzheimer’s – the tissue has progressively fewer nerve cells and connections.
While they cannot be seen or tested in the living brain affected by Alzheimer’s disease, postmortem/autopsy will always show tiny inclusions in the nerve tissue, called plaques and tangles: Plaques are found between the dying cells in the brain – from the build-up of a protein called beta-amyloid (you may hear the term “amyloid plaques”).
The abnormal protein clumps, inclusions, in the brain tissue are always present with the disease, but there could be another underlying process that is actually causing the Alzheimer’s – scientists are not yet sure. This sort of change in brain nerves is also witnessed in other disorders, and researchers want to find out more than just that there are protein abnormalities – they also want to know how these develop so that a cure or prevention might be discovered. Researchers do not fully understand why the changes that lead to Alzheimer’s disease occur. Several different factors are believed to be involved. Risk factors for developing the condition include aging, a family history of Alzheimer’s, and carrying certain genes.
Alzheimer’s disease is not simple to diagnose – there is no single test for it. For this reason, the first thing doctors do is to rule out other problems before confirming whether mental signs and symptoms are severe enough to be a kind of dementia or something else.
Signs and symptoms 10
Stages of Alzheimer’s disease
Effects of ageing on memory but not AD
•Forgetting things occasionally
•Misplacing items sometimes
•Minor short-term memory loss
•Not remembering exact details
Early stage Alzheimer’s
•Not remembering episodes of forgetfulness
•Forgets names of family or friends
•Changes may only be noticed by close friends or relatives
•Some confusion in situations outside the familiar
Middle stage Alzheimer’s
•Greater difficulty remembering recently learned information
•Deepening confusion in many circumstances
•Problems with sleep
•Trouble knowing where they are
Late stage Alzheimer’s
•Poor ability to think
•Repeats same conversations
•More abusive, anxious, or paranoid
There is no known cure for Alzheimer’s disease – the death of brain cells in the dementia cannot be halted or reversed.
There are no disease-modifying drugs available for Alzheimer’s disease but some options may reduce its symptoms and help improve quality of life. There are four drugs in a class called cholinesterase inhibitor approved for symptomatic relief in the US: Donepezil (brand name Aricept), Rivastigmine (Exelon), Tacrine (Cognex). A different kind of drug, memantine (Namenda), an NMDA receptor antagonist, may also be used, alone or in combination with a cholinesterase inhibitor.
As with other types of dementia and neurodegenerative disease, a major part of therapy for patients with Alzheimer’s comes from the support given by healthcare workers to provide dementia quality-of-life care, which becomes more important as needs increase with declining independence.3
Alzheimer’s disease is treated in India with Ayurveda 11. Ashwaganda an ancient Herb used in Ayurveda is Proven to be a Potential Cure for Alzheimer’s 12. Curcumin (Haldi) is more effective in inhibiting the formation of the protein fragments than many other potential Alzheimer’s treatments. Optimize vitamin D, Vitamin B12, a nutritious diet rich in folate and Coconut Oil is tried in treating Alzheimer’s Disease 13.
Challenge your mind daily. Mental stimulation, especially learning something new, such as learning to play an instrument or a new language, is associated with a decreased risk of Alzheimer’s. Researchers suspect that mental challenge helps to build up your brain, making it less susceptible to the lesions associated with Alzheimer’s disease. 12.