Alzheimer's disease is a devastating condition that affects millions of people around the world. It is a progressive disorder that slowly erodes the memories and cognitive abilities of those afflicted.Unfortunately, there is no cure for this debilitating disease, but there are medications available that can help to slow the progression of the symptoms and provide relief from the behavioral problems associated with it. These medications can help to improve the quality of life for those living with Alzheimer's, and provide some comfort to their families.
OVERVIEW
What is Alzheimer's disease?
The signs and symptoms of Alzheimer's get worse with time. In fact, according to doctors, the illness process could last up to 10 years before Alzheimer's disease symptoms start to show.
When memory issues do become apparent, they are frequently classified as mild cognitive impairment (MCI). At this point, the brain adjusts to the effects of the disease, affecting intellectual function but leaving the ability to operate and live independently unaffected.
MCI may still be stable in some individuals at this point. But dementia is most likely to develop in MCI patients. Dementia is most frequently caused by Alzheimer's disease. (Dementia may furthermore be brought on by a number of conditions, including Parkinson's disease, dementia with Lewy bodies, vascular dementia, frontotemporal dementia, and others.) Unlike MCI, daily function is impacted by dementia.
When Alzheimer's disease-related dementia reaches its advanced stages, affected people are unable to speak, recognise friends and relatives, or take care of themselves.
How common is Alzheimer’s disease?
In India, deaths from Alzheimer's and dementia reached 126,593 in 2020, accounting for 1.49% of all deaths, according to the most recent WHO data. India is ranked #137 in the world by age-adjusted Death Rate, which is 14.60 per 100,000 people.
Alzheimer's disease affects one in ten people over the age of 65 and over half of those over the age of 85. In their 40s, those with Alzheimer's disease are also susceptible. Every decade after age 60, a growing number of people develop Alzheimer's disease. By 2050, there will be 14 million Alzheimer's patients in India and 106 million worldwide, according to the Alzheimer's Association, as a result of population ageing and the lack of effective treatments.
SYMPTOMS AND CAUSES
What causes Alzheimer’s disease?
Protein accumulation that is out of the ordinary in the brain is which leads to Alzheimer's disease. These proteins, known as amyloid protein and tau protein, accumulate and cause cell death.
Over 100 billion nerve cells as well as other types of cells make up the human brain. Together, the nerve cells carry out all of the communications required to carry out tasks like thinking, learning, remembering, and planning. The accumulation of amyloid protein, which forms bigger aggregates known as plaques in the brain cells, is thought to occur. Tau tangles are made of twisted tau protein fibres.
These plaques and tangles obstruct nerve cell communication, which stops the nerve cells from performing their functions. The symptoms experienced by people with Alzheimer's disease are caused by the slow and continuous death of the nerve cells, which begins in one area of the brain (often in the area of the brain that governs memory) before spreading to other places.
What are the symptoms of Alzheimer’s disease?
Alzheimer's disease symptoms differ from person to person and get worse over time.
Symptoms of the disease include:
- memory decline One of the initial signs of Alzheimer's disease is typically this.
- Putting objects in unusual places
- Confusing events, time, and location
- repeating inquiries
- difficulty budgeting and paying expenses
- familiar tasks are more difficult to do or take longer to complete
- Losing one's way/wandering
- being unable to fall asleep
- psychological and behavioural changes, such as tension, anxiety, and hostility
- having irrational suspicions about one's relatives, friends, or caretakers
- bad decision-making or reasoning
- Having trouble distinguishing friends and family
- Having trouble picking up new information and recalling recent occurrences
- difficulty with complex chores, such dressing or cooking
- Experiencing delusions, paranoia, or hallucinations
- speaking or finding the correct words is difficult
- difficulty with reading, writing, and math
- difficulty swallowing and walking
DIAGNOSIS AND TESTS
How is Alzheimer’s disease diagnosed?
These tests are used to diagnose Alzheimer’s disease or to rule out other medical conditions that cause symptoms similar to Alzheimer’s disease:
- Medical history. The doctor will inquire about the patient's present and previous illnesses, the drugs they are currently taking, and any history of Alzheimer's disease or other memory impairments in the patient's family. Additionally, he or she will perform a neurologic exam and assess all current vital signs, including blood pressure, heart rate, temperature, and pulse rate (check reflexes and coordination, eye movement, speech and sensation).
- Blood and urine tests. These Standard laboratory tests such blood counts, vitamin levels, liver and kidney function, mineral balance, and thyroid gland function tests are done to rule out other potential causes of symptoms.
- Mental status testing. These tests include tests of memory, problem solving, focus, counting, and language skills. This type of testing can also monitor the progress of Alzheimer’s disease.
- Neuropsychological testing. This exam includes tests to assess attention, memory, language, the ability to plan and reason, the ability to change behavior, as well as personality and emotional stability. This type of testing can also monitor the progress of Alzheimer’s disease.
- Spinal tap. Also called a lumbar puncture, this test checks for the tau and amyloid proteins that form the plaques and tangles seen in the brains of people with Alzheimer’s disease.
- Brain imaging tests:
- Computed tomography (CT). This scan reveals physical changes in the structure of brain tissue seen in the later changes of Alzheimer’s disease, including decrease in the size of the brain (atrophy), widening of the indentations of the brain tissues, and enlargement of the fluid-filled chambers of the brain.
- Magnetic resonance imaging. This scan can also show brain atrophy. In addition, it can identify strokes, tumors, the buildup of fluid on the brain, and other structural damage that can cause symptoms similar to Alzheimer’s disease.
- fMRI (functional MRI). This is a type of MRI that measures brain activity in a select area by detecting changes in blood flow. This test is being used by researchers to see how the brain changes at different stages of Alzheimer’s disease. It is also being used to evaluate treatments for Alzheimer’s disease before a person has symptoms.
- Positron emission tomography. This scan shows the abnormal brain activity in a person affected by Alzheimer’s disease. It can also help diagnosis Alzheimer’s disease versus other forms of dementia
- Amyloid PET. This scan shows the buildup of amyloid protein in the brain.
- FDG PET. This scans shows how well brain cells use glucose. A decline in the absorption of glucose is a sign of Alzheimer’s disease.
MANAGEMENT AND TREATMENT
Which medicines are used to treat Alzheimer’s disease?
There is no cure for Alzheimer’s disease, but available medications temporarily slow the worsening of dementia symptoms and help with behavioral problems that may appear during the course of the disease.
Four medications representing two drug classes are currently approved by the Food and Drug Administration (FDA) to treat the symptoms of Alzheimer’s disease. These drugs are the cholinesterase inhibitors and a NMDA antagonist.
Cholinesterase inhibitors. The cholinesterase inhibitors are all approved to treat the symptoms of mild to moderate Alzheimer's disease (AD). Cholinesterase inhibitors include:
- Donepezil (Aricept®) (also FDA-approved to treat moderate to severe disease)
- Rivastigmine (Exelon®) and Exelon patch
- Galantamine (Razadyne®)
These drugs work by blocking the action of acetylcholinesterase, the enzyme responsible for destroying acetylcholine. Acetylcholine is one of the chemicals that helps nerve cells communicate. Researchers believe that reduced levels of acetylcholine cause some of the symptoms of Alzheimer's disease. By blocking the enzyme, these medications increase the concentration of acetylcholine in the brain. This increase is believed to help improve some memory problems and reduce some of the behavioral symptoms seen in patients with Alzheimer’s disease.
These medications do not cure Alzheimer’s disease or stop the progression of the disease. The most common side effects of these drugs are nausea, diarrhea, and vomiting. Some people may have loss of appetite, insomnia or bad dreams.
NMDA antagonist. Memantine (Namenda®) is approved by the FDA for treatment of moderate to severe Alzheimer's disease. It blocks the neurotransmitter glutamate from activating NMDA receptors on nerve cells, keeping the cells healthier. This medication works differently than the cholinesterase inhibitors. Memantine can be taken alone or taken together with a cholinesterase inhibitor.
Patients with moderate to severe Alzheimer's who were treated with memantine performed better in studies measuring the common activities of daily living such as eating, walking, toileting, bathing, and dressing compared with patients taking placebo. Patient with lower functioning may benefit the most.
- Summary of medications to treat the symptoms of Alzheimer’s disease. The four current medications approved for Alzheimer’s disease have shown modest effects in preserving brain function. They may help lessen or stabilize the symptom of Alzheimer’s disease for a period of time. Due to the side effects of these drugs – especially the gastrointestinal effects -- doctors and patients should talk about their use before prescribing them. Also, these drugs should be stopped when dementia reaches advanced stages.
Managing behavior changes. Medications are available to treat some of the common behavioral symptoms of Alzheimer’s disease. For example, antidepressant drugs can be used to treat anxiety, restlessness, aggression and depression. Anti-anxiety drugs can be used to treat agitation. Anticonvulsants are sometimes used to treat aggression. Antipsychotics can be used to treat paranoia, hallucinations, and agitation. Some of the side effects of these drugs include confusion and dizzi
ness, which can increase the risk of falls. Therefore these drugs are typically used either for short periods of time, only when behavioral problems are severe, and only after safer and/or other non-drug therapies have been tried first.
What are some risk factors for Alzheimer’s disease?
Risk factors for the development of Alzheimer’s disease include:
- Age. Increasing age is the primary risk factor for developing Alzheimer’s disease.
- Genetics (runs in families). There is a certain gene, apolipoprotein E (APOE) that is associated with late-onset Alzheimer’s disease. Other genes have been associated with early-onset Alzheimer’s disease.
- High blood pressure
- High cholesterol
- Diabetes
- Smoking
- Obesity
Researchers believe the presence of the last five risk factors mentioned above might reduce the clearance of amyloid protein from the brain, which then increases the risk of developing Alzheimer’s disease. In particular, the presence of a number of these risk factors at the same time and while the person is in his or her 50s is associated with a higher risk of Alzheimer’s disease.
There may be some ways to reduce the risk of mental decline. In general, living a healthy lifestyle protects the body from strokes and heart attacks and is believed to also protect the brain from cognitive decline. Scientists can’t absolutely prove the cause and effect of the following factors, but studies have shown a “positive association.”
- Stay mentally active. Play board games, read, do crossword puzzles, play a musical instrument, audit courses at a local community college, do other hobbies that require “brain power.”
- Get physically active. Exercise increases blood flow and oxygen to the brain, which may directly affect brain cell health. Wear protective head gear if engaging in activities that increase the risk of a head injury.
- Stay socially active. Regularly talk with friends and family, join in on group activities (such as worship services, exercise classes, choir, book clubs)
- Follow the Mediterranean or DASH diet or another healthy diet that includes antioxidants. Consume beverages that contain alcohol in moderation — no more than one drink per day for women and no more than two per day for men.
What is the outlook for people with Alzheimer’s disease?
Alzheimer’s disease gets worse over time and is ultimately fatal. Persons with Alzheimer’s disease live, on average, four to eight years after diagnosis. Some patients can live as long as 20 years after diagnosis. The course of the disease varies from person to person.
References
- Neumann, U.; Ufer, M.; Jacobson, L.H.; Rouzade-Dominguez, M.L.; Huledal, G.; Kolly, C.; Luond, R.M.; Machauer, R.; Veenstra, S.J.; Hurth, K.; et al. The BACE-1 inhibitor CNP520 for prevention trials in Alzheimer’s disease. Embo Mol.
- Vandenberghe, R.; Riviere, M.E.; Caputo, A.; Sovago, J.; Maguire, R.P.; Farlow, M.; Marotta, G.; Sanchez-Valle, R.; Scheltens, P.; Ryan, J.M.; et al. Active Abeta immunotherapy CAD106 in Alzheimer’s disease: A phase 2b study. Alzheimers Dement
- National Institute on Aging. Alzheimer’s Disease Fact Sheet. (https://www.nia.nih.gov/health/alzheimers-disease-fact-sheet)
- Alzheimer’s Association. What is Alzheimer’s. (https://alz.org/alzheimers-dementia/what-is-alzheimers) (https://alz.org/)
- Kim LD, Factora RM. Alzheimer’s dementia: Starting, stopping drug therapy.
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