Dementia

Overview

Dementia is a group of symptoms that affects memory, reasoning, and mental tasks which is caused mainly from Alzheimer's Disease(60%-80% of cases). It is a syndrome that is caused by diseases of the brain. It is usually a chronic and progressive issue that is caused by disturbances in higher cortical functioning such as memory, orientation, thinking, calculation, comprehension, learning capacity, judgement, and language. The main population affected by dementia is older people. Only 2% of people suffer from dementia under age 65, and the likelihood doubles for every 5 years after. Dementia is one of the most debilitating issues later in life. Some of the conditions that cause dementia are reversible such as thyroid issues and vitamin deficiencies. The serious mental decline that occurs with dementia is not a normal part of ageing.


Anatomy and Physiology

Diagnosis/Causes

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Researchers are currently trying to find biomarkers that will be able to detect Alzheimer's Disease(AD) at an early stage in order to treat patients. The earlier it is detected and treated the more effective it will be. The ways researchers find biomarkers is by neuroimaging, looking for medial temporal atrophy on MRI's, looking for reduced glucose metabolism in temporoparietal cortices on PET scans, and looking at images of brain amyloid with PET scans. It is also important for the neurologist to be counseling patients who feel they have memory concerns. The neurologist would not make a diagnosis unless there is clear cognitive impairment.
Observations have been showing a link between midlife obesity and dementia later in life. With both dementia and midlife obesity there is data that shows white matter hyperintensities and decreased hippocampal amounys.
The main cause of dementia is from Alzheimer's disease which is described as a tangling of neurofibrillary and cortical amyloid plaques. Vascular dementia is another cause which occurs when the supply of oxygen to the brain is cut off multiple times by strokes or issues with blood vessels. This repeated oxygen deprivation causes damage to brain tissue and function. Once the course of dementia begins it is not likely that the disorder can be altered. Treatments for the symptoms in the disorder can help the patient and their caregivers immensely.
There has been evidence that limited education, depression, smoking, vascular disease, high blood pressure, and high chloseterol levels. and head injuries, are risk factors in developing AD which causes dementia.
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Stages and Symptoms of AD and Dementia

Stage 1

The first stage is sometimes undetected as relatives and friends view a person as experiencing old age. This is because the onset of the disease is gradual. The person may have significant memory loss as this stage as well as language problems. The person also may have difficulty making decisions and start to become unmotivated and inactive. Depression, anxiety, as well and aggression are signs as well. The person may exhibit a loss in their hobbies and activities.

Stage 2
The progression of the disease causes clear restrictions and limitations. A person with dementia has a hard time with everyday living as well as forgetfulness of recent events and names. They have difficulty living alone because of inability to cook, clean, and shop. Personal hygiene is compromised as well as dressing, washing, and other daily chores. They may experience hallucinations as well as wandering and behavior problems.

Stage 3
This stage is when the person has total dependency on others and becomes inactive. The physical aspect of the disease is very noticeable and memory problems become very serious. They have a difficult time eating, communicating, lack of recognition of relatives, friends, and familiar objects. They have difficulty walking, swallowing, incontinence, and inappropriate behavior in public.

Dementia is caused mainly by damage to the cells of the brain. This damage messes up the ability for brain cells to communicate with each other which shows outwardly as difficulty in communicating, thinking, behavior, and feelings. The distinct regions of the brain that are responsible for memory, judgement, and movement, etc. cannot carry out their function as normal which debilitates the affected person's ability to function. These changes in the brain are permanent, irreversible, and get worse over time.

Taupothies


In some forms of dementia a protein called tau clumps inside nerve cells in the brain. This clumping causes the cells in the brain to stop functioning a die. A taupothie is a disorder that is associated with an accumulation of tau.
In Alzheimer's Disease the tau protein twists in shape and forms bundles which are called neurofibrillary tangles which occurs within the neurons. Plaques of amyloid, another protein, are what is thought to cause malfunction in nerve cells as well as cell death.
Other tauopathies:

Corticobasal degeneration (CBD)- A progressive neurological disorder cause by nerve loss and the shrinkage of specific parts of the brain such as the cerebral cortex and basal ganglia. The disorder progresses gradually and generally tends to affect one side of the body over the other. Some signs include memory loss, involuntary muscular jerks and contractions, alien limb, muscle rigidity,and postural instability.

Frontotemporal disorders (FTD)- This is caused by brain diseases that affect the frontal and temporal lobes of the brain. This accounts for 10 % of all dementia cases. Some forms but not all of them are tauopathies. The nerve cells in the brain's frontal lobes affect the ability for a person to reason, make decisions, prioritize and multitask, act appropriately, and control movement. People show a rapid decline in the first few years but can live with this disorder for 2-10 years. This disorder is associated with progressive neuromuscular weakness in some cases. The signs and symptoms can vary between the individuals depending on the part of the brain affected.


Environmental Factors

Environmental factors can play a role dementia and the development of certain types. It is possible that a person's genetic mutation may play a role in the way they are affected by the environment.

Anoxia- This is a condition that is related to hypoxia that are a state when the supply of oxygen to an organ's tissues are decreased. This can lead to the loss of neurons in the brain which leads to injury of the brain. The signs of this type of dementia show a patient with confusion, changes in personality, hallucinations, or memory loss. This form of dementia occurs commonly in people who survive cardiac arrest.

Poisoning- The exposure to heavy metals such as lead and mercury, or other poisonous materials can cause symptoms of dementia. Depending on how severe the brain is damaged the symptoms may or may not be able to be resolved.

Substance abuse- Substance abuse such as alcohol and drugs sometimes show signs of dementia. This form of dementia is called substance- induced persisting dementia.


Summary

Dementia is not a disease, nor is it a normal part of ageing. Of the 24 million people affected mostly elderly people are affected. Dementia awareness is low in most regions of the world because it is assumed dementia is a normal part of ageing so there is inefficient care for those suffering. There is no cure for dementia although there is a lot that can be done to improve the quality of life for both those suffering from dementia as well as their caregivers.

Quiz

Dementia is a disease that affects the functions of daily life T/F
A natural part of ageing is dementia T/F
The symptoms of dementia is fully reversible T/F

Glossary

Anoxia- A state when the supply of oxygen to an organ's tissues are decreased.
Alzeiemer's Disease- A progressive mental deterioration that can occur in middle or old age, due to generalized degeneration of the brain.
Biomarkers- Indicators that detect an early on whether a person has AD
Taupathies- A clumping of tau proteins that causes the cells in the brain to stop functioning a die. A taupothie is a disorder that is associated with an accumulation of tau.


Further Readings

Sources

Filley, Christopher M. "Dementia." Dementia. N.p., 10 Dec. 2010. Web. 22 Dec. 2015.

Neurological Disorders. London: Macmillan Magazines, 1999. Web. 22 Dec. 2015.

"What Is Dementia?" Dementia – Signs, Symptoms, Causes, Tests, Treatment, Care. N.p., n.d. Web. 23 Dec. 2015.


"Dementia: Hope Through Research." Dementia: Hope Through Research. N.p., n.d. Web. 23 Dec. 2015.

Quiz Answers

1. F
2. F
3. F