Alzheimer’s disease is usually associated with old age. Dr. Alois Alzheimer from Germany found out about the disease after the death of his patient of an unknown mental illness while undergoing treatment. He later examined her brain and made a discovery that there were some abnormalities in the functioning of the brain cells. While performing a brain autopsy to the patient, he observed twisted bands of fiber inside the nerve cell and noted deposits surrounding them. The name Alzheimer came from the doctor’s name since the two observations he made are the main characteristics of this disease. To make a conclusion on the presence of the disease, one also considers the loss of connections between the nerve cells.
This disease is the most common form of dementia among elderly people. Dementia is a condition where there is a decline in one's mental functioning, loss of memory,and reduction in the thinking capacity and reasoning. People with dementia find it difficult to engage in activities that they have previously engaged in with ease. There are two forms of dementia: Alzheimer's disease and vascular dementia. When arteries in the brain harden, it results in blockage of blood flow, commonly known as vascular dementia. Both Alzheimer's and vascular dementia have irreversible symptoms; however, for Alzheimer's disease the symptoms progressively worsen.
Occurrence of Alzheimer
Occurrence of this disease cannot be linked to a particular factor because its causes differ from patient to patient. It has not yet been discovered what actually causes Alzheimer's, but since it mainly occurs among older adults, scientists have found out that changes occurring in the brain could be the principal cause. Shrinking of certain parts of the brain, production of free radicals, break down in energy production, and inflammation are the changes associated with Alzheimer's disease. These changes occur as a result of complex biological processes that take place inside the brain over many years. These changes harm the neurons in the brain resulting to Alzheimer's disease.
The human brain has millions of cells known as neurons that generate and transmit electric signals. The signals transmitted allow us to think, feel and remember. For a person with Alzheimer's disease these neurons get destroyed hence signals are not well transmitted; this results in a decline in brain functioning. The thinking capacity of such individual lowers and its ability to recall existing memories declines. With time, more neurons get destroyed, and brain functioning totally get damaged, At this point, when neurons get damaged, the individual is unable to do anything.
They lose their ability to think, understand, recall, communicate, and unable to accomplish a task, no matter how unpretentious it may be. Scientists have not yet found why these neurons die. These neurons die predominantly in the cerebral cortex and the hippocampus, causing them to shrink. Abnormal structural changes in the brain, tangles and plagues also lead to death of the neurons; thus, neurotransmitters between neurons reduce. Reduction in acetylcholine, one of the neurotransmitters results in loss of memory and inability to learn.
There are various factors that contribute to the development of the disease. These factors revolve around the genetic make up of an individual, his/her life style, and environmental factors. This disease differs from one person to another since people’s lifestyle and genetic make up are different. These risk factors include age, genetics, cardiovascular disease, type two diabetes, inflammation, oxidative damage, obesity, hypertension, female gender, head injury, and low immune system.
People at the age of sixty and above have higher chances of getting the disease than younger people. It is more prevalent to people aged between sixty and seventy five. Half of people aged eighty five and above have Alzheimer's disease. More women than men have Alzheimer's because women generally live longer than men (Rolfes, Pinna, & Whitney, 2009).
Genetics play a large role in determining one's risk of having the disease. If it has previously affected somebody in your family, you are more likely to get the disease, than those without such a family history. The risk is elevated in case if people who have the disease are your immediate relatives like your siblings and your parents. When more than one of these people have it, the risk increases. Apolipoprotein E (APOe), a gene associated with Alzheimer's disease, which we all inherit from our parents in three different forms APOE2, APOE3 and APOE4. Inheritance of ApoE2 fully protects against Alzheimer's disease, whereas ApoE3 plays a neutral role, and ApoE4 increases the risk of Alzheimer's. APOE4 is found in more people than APOE2; therefore, more people are at a risk of suffering from the disease. If one inherits APOE4 from one of his/her parents, he/sheis at a high risk of contracting the disease; the risk is higher if one gets the gene from both parents.
APOE4 also makes Alzheimer's symptoms to appear at an early age. There are other genes known as deterministic genes; when one happens to inherit them, it guarantees him/her that he/she are going to suffer from the disease. Some of these genes associated with Alzheimer’s disease include amyloid precursor protein (APP) presenilin-1 (PS-1), and presenilin-2 (PS-2). When these deterministic variations cause Alzheimer’s disease, one suffers from autosomal dominant Alzheimer’s disease. This one occurs before the age of sixty; symptoms show up at thirty or forty years. If these genes are present in a family, multiple family members get affected. There are remarkably few cases of autosomal dominant Alzheimer disease, also known as familial Alzheimer's disease.
Discovery of genes that cause Alzheimer’s occurred at different times. Amyloid precursor protein, which was discovered in 1987, causes an inherited form of Alzheimer. It was the first gene with mutations to cause this. Presenilin-1 (PS-1), discovered in 1922, is the second gene with mutations found to cause early-onset of Alzheimer's. Its variations are the most common cause of early onset of Alzheimer's. Presenilin-2 (PS-2), discovered in1993, is the third gene with mutations found to cause early-onset Alzheimer's disease (Rolfes, Pinna, & Whitney, 2009). APOE4, identified in 1993, is the first gene with variations that found to increase the risk. Having this mutation does not guarantee one that he/she will suffer from the disease. However, this gene has the greatest known impact.
Cardiovascular diseases also increase the chance of getting Alzheimer's disease. These include high blood pressure, high cholesterol levels, heart disease, and stroke. High blood pressure may result in the damaging of the blood vessels, which leads to a disruption of regions necessary for decision-making, memory, and verbal skills, which could make the disease worsen. On the other hand, high cholesterol levels inhibit the ability of blood to clear protein from the brain.
Head trauma also increases chances of Alzheimer's. Previous head injuries that could have led to unconsciousness expose the individual to future risks of contracting Alzheimer’s disease.
When insulin does not work properly to convert blood sugar into energy, one suffers from type 2 diabetes. Type 2 diabetes results in production of higher levels of blood sugar and insulin, which end up harming the brain and possibility of leading to progression of Alzheimer's.
Mild cognitive impairment also increases the chances of getting Alzheimer's. People with this condition have memory problems or other symptoms of cognitive decline, but less severe than those of dementia. The Alzheimer's diseases may increase their risks due to those disorders.
Inflammation occurs when immune cells get rid of dead cells and other waste products. Inflammation increases the risk of contracting Alzheimer's. Oxidative damage occurs when free radicals try to seek stability by attacking other molecules. This harms cells and tissues and may also lead to the neuronal brain cell damage caused by Alzheimer's (Zeisel, 2011).
Other factors that expose people to contracting the disease depend on one's lifestyle. A person who smokes has a higher chance of suffering from a cardiovascular disease than one who doesn't smoke. This, in turn, increases their chance of getting Alzheimer's disease. Exposure to environmental toxins such as aluminum, may make a person more susceptible to Alzheimer's. Unhealthy eating habits, which may lead to an increase in cholesterol, expose the individual to a higher risk of contracting the disease. Poorly controlled diabetes also increases chances of suffering from Alzheimer's. Poor level of education can also be associated with the increased chances of developing Alzheimer's disease.
Signs and Symptoms
Alzheimer's disease has various signs and symptoms. The early symptoms include increasing forgetfulness and mild confusion. Memory loss associated with Alzheimer's disease is more severe than the memory loss that we experience in our daily lives. People with Alzheimer's keep repeating things, forget pivotal events and conversations without remember them later, forget names of family members and everyday objects, and often misplace possessions and try to retrieve them in illogical positions (Zeisel, 2011). These people are unable to tell what day it is, the time of the year, their place of living, or even what they are going through. They also have difficulty in understanding their surrounding, as Alzheimer's disrupts their brain's ability to interpret what they see.
Alzheimer's also decreases one's reasoning and thinking ability, especially about concepts like numbers. This makes it difficult for the affected to manage their finances, balance their check books, and make payments on time. With time, these difficulties may progress to inability to recognize and deal with numbers. It also becomes increasingly challenging for them to do their daily chores such as cooking and driving. Those with Alzheimer's have difficulty in finding words to identify objects, with their ability to read and write decreases.
Behavioral Changes Associated With Alzheimer
People with Alzheimer's disease experience changes in their behavior and personality. They may experience social withdrawal, depression, anxiety, distrust in others, irritability and aggressiveness, increased stubbornness, mood swings, wandering, and changes in sleeping habits.
As Alzheimer's disease progresses, the symptoms worsen. Affected people tend to become more upset, agitated and rest less, and their ability to perform basic life functions such as breathing and swallowing become utterly impaired.
There are three stages of Alzheimer’s; these include the early stage, moderate stage, and the severe stage. The early stage is characterized by frequent memory loss, mainly on recent conversations and events. They also ask repeated questions; problems in expressing and understanding language. They experience mild coordination problems; writing and using objects becomes difficult.
Depression can occur, accompanied by mood swings. They need to be reminded about their daily activities, and may have difficulty driving. The middle or moderate stage is characterized by frequent memory loss, forgetfulness about ones history, and difficulty in recognizing friends and family. They also have difficulty in speech, unusual reasoning, and confusion about current events such as time and place. They begin to get lost in places that they have been to before, have sleepless nights, and changes in mood and behavior, which can be increased by stress and change. Slowness, rigidity, and tremors dictate movement and coordination. Just like in the first stage, they also need to be reminded what they cannot recall, and be assisted in the daily activities. The severe or late stage is characterized by increased confusion about the past and present.
Increased loss of ability to remember, communicate, or process information, severe or total loss of verbal skills, and inability to take care of themselves. They often fall down, and it becomes challenging for them to move from one area to another. They have problems with swallowing, illness, and extreme problems with mood, behavior, and hallucinations. In this stage, the person will need continuous intensive support and care.
Alzheimer’s is a disease of the brain, before one experiences symptoms of Alzheimer's, the brain already has some of its structures doted with plagues and tangles that characterize the illness.
Comparison between a brain of a healthy person and that of a person with Alzheimer's disease revealed that the hippocampus' volume lowers by about 4 percent in two years for a healthy person, but the volume of the hippocampus of people with Alzheimer's decreases by 10 percent within the same period. Brain shape changes in healthy people tend to be within a small part of the structure. In people with Alzheimer’s disease, shape changes incorporate larger parts of the hippocampus, including the area where plaques and tangles appear. Both brains that of a healthy person and that of somebody suffering from Alzheimer's experience changes, but the changes in people with Alzheimer's disease were more pronounced. In Alzheimer’s disease, brain structures have their normal shape at the beginning; changes begin to occur as the disease progresses (Whitney & Rolfes, 2011).
Early damages to some parts of the brain have occurred by the time changes in hippocampal shape occur. Those changes in shape happen at the same time when patients start showing symptoms of Alzheimer’s disease. This provides strong evidence that the shape changes in the hippocampus cause at least some of the symptoms of Alzheimer’s disease. Alzheimer's disease also causes changes in volume of the brain. However, it is difficult to tell since brain sizes are dependent on the size of a person.
Hippocampus tends to be smaller in people with Alzheimer's than in ordinary people. The cerebral cortex of a person with Alzheimer's disease shrinks; hence, it becomes different from that of a healthy person. Cerebral cortex, outer surface of the brain controls all the intellectual functioning of the brain. Other changes that occur in the brain include a decrease in the amount unwanted substance in the brain folds, and grossly enlarged spaces known as the sulci.
There is also presence of amyloid plagues outside the neurons and neurofibrillary plaques inside the neurons, where the neurons are the nerve cells within the brain.
People without Alzheimer's also have plagues and tangles, but the increased amount of plagues and tangles signifies the presence of Alzheimer's disease. Amyloid plague, made up of B-amyloid protein, which is part of the much larger protein, amyloid precursor protein, which are amino acids. Amyloid precursor protein made in the cell has two key pathways involved in their break down. One pathway causes no problem since its normal. The second has resulted in changes seen in Alzheimer's and other dementias. In the second pathway, enzyme, Y-secretase and B-secretase, splits the amyloid precursor protein. The fragments that result from the divide join together and make a short chain - an oligomer. Oligomers, also known as amyloid-beta derived diffusible ligands (Whitney & Rolfes, 2011).
Presence of amyloid beta 42 in the brain causes communication problems between neurons. This oligomer produces small fibers, which when stack together form the amyloid plaque. When some of these plaques get into the membrane of the neurone cell, they cause substances outside the cell to leak into it hence further damage. This damage causes death of neurons due to the buildup of Amyloid beta 42 peptide, leading to neurone death. Neurofibrially tangles lead to the death of the brain cells.
Behavioral changes associated with Alzheimer's disease include how a person thinks and feels. These result in the person being extremely irritable; hence, taking care of a such person will need a lot of patience and understanding. These changes come about because Alzheimer's disease affects the brain. The individual’s behavior alters some of the brain's functions. Behavior problems such as aggression, wandering, suspicion, agitation, confusion, hallucinations, and repetition come because of brain damage.
Treatment of Alzheimer's disease involves encouraging people to adapt a healthy lifestyle; hence, reducing the chances of increased cholesterol levels and acquiring some of the lifestyle associated with the illness. Drugs are administered to those who already have the disease. Drugs used to treat Alzheimer's disease include galantamine, rivastigimine, and donezepil. These drugs improve memory. They also improve alertness and motivation. Moreover, it makes some people to feel brighter in their mood and enable them to perform tasks that they could not perform (Whitney & Rolfes, 2011).
Still, these drugs have side effects, which include feeling sick, loss of appetite, tiredness, diarrhea, muscle cramps, and poor sleep. These may be reduced by taking the drug in small amounts, or taking the drug after meals. The side-effects disappear as days go by and will go away if the medication stops. These drugs have acetylcholine, which is responsible for passage of messages between brain cells involved in memory. The death of brain cells in Alzheimer's disease leads to a reduction in acetylcholine. Administration of Cholinesterase Inhibitors controls the breakdown of acetylcholine hence increasing its levels in the brain. With this, a reduction in the symptoms of Alzheimer's disease occurs.
These drugs start from a low dose which increases over time. Other treatment methods include taking of ginkgo biloba, a naturally occurring substance extracted from Maidenhair tree which enhances memory. Taking foods rich in vitamin E reduces the progression of Alzheimer's disease. Some of the vital vitamin E sources include soya beans, whole grain foods, fish liver oils, nuts, cotton and sunflower seeds, and corn. Other drugs that can be taken include Rember, which reduces tau protein responsible for tangles found in the brain cells of people with Alzheimer's. This treatment slows progression of the disease. Immunization of people against the amyloid hence reduction of plagues found in people with Alzheimer's disease. Dimebon, previously used to treat hay fever, can be used to protect nerve cells. Eternacept blocks the chemical, which causes inflammation and death of the cells.
Alzheimer’s disease should not be allowed to continue affecting a larger number of people. Those in a position where they can see to it that spread of the disease has reduced, should do so. Studies show that some years to come more individuals will be suffering from the disease, but we should not allow this to happen. Let us embrace healthy lifestyles, which will alienate us from the risk of contracting Alzheimer's disease. If one has the risk of getting the disease due to inheritance, they should seek medical advice the moment they get to know that they are more susceptible to acquiring the disease. Those who already have Alzheimer’s disease should continue with the prescribed treatment and do not expose themselves to other risk factors that may result in severe conditions.