Alzheimer’s disease is a neurological disorder in which the death of brain cells causes memory loss and cognitive decline. The brain loses its function and it affects thinking, and behavior.
Facts on Alzheimer’s disease
Alzheimer’s disease is the most common type of dementia. The term “dementia” describes a loss of mental ability associated with gradual death of brain cells.
-People of age 65 and older, are mostly affected. Also it happens to people under the age of 65.
-It is the only cause of death in the US top 10 that cannot be prevented, cured or slowed.
-Almost two thirds of Americans with Alzheimer’s disease are women.
-Alzheimer’s and other dementias cost the nation $226 billion per year.
Due to the physical and emotional toll of caregiving, Alzheimer’s and dementia caregivers had $9.7 billion in additional health care costs of their own in 2014.
Causes of Alzheimer’s disease
-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 tangles are within the brain neurons – from a disintegration of another protein, called tau.
Symptoms of Alzheimer’s disease
These are base on tests, diagnosis and symptoms noticed by patients, or people close to them.
Symptoms can be diagnosed at any stage of Alzheimer’s dementia and the progression through the stages of the disease is monitored after an initial diagnosis, too, when the developing symptoms dictate how care is managed.
Of course, the very nature of the symptoms can be confusing for both a patient and the people around them, with different levels of severity. For this reason, and because symptoms could signal any of a number of diagnoses, it is always worthwhile seeing a doctor.
For doctors to make an initial diagnosis of Alzheimer’s disease, they must first be satisfied that there is dementia – guidelines spell out what dementia consists of. It involves cognitive or behavioral symptoms that show a decline from previous levels of “functioning and performing” and interfere with ability “to function at work or at usual activities.”
1. Worsened ability to take in and remember new information, for example:
-Repetitive questions or conversations
-Misplacing personal belongings
-Forgetting events or appointments
-Getting lost on a familiar route.
2. Impairments to reasoning, complex tasking, exercising judgment:
-Poor understanding of safety risks
-Inability to manage finances
-Poor decision-making ability
-Inability to plan complex or sequential activities.
3. Impaired visuospatial abilities (but not, for example, due to eye sight problems):
-Inability to recognize faces or common objects or to find objects in direct view
-Inability to operate simple implements, or orient clothing to the body.”
4. Impaired speaking, reading and writing:
-Difficulty thinking of common words while speaking, hesitations
-Speech, spelling, and writing errors.
5. Changes in personality and behavior, for example:
-Out-of-character mood changes, including agitation; less interest, motivation or initiative; apathy; social withdrawal
Loss of empathy
-Compulsive, obsessive or socially unacceptable behavior.
Once the number and severity of these example symptoms confirm dementia, the best certainty that they are because of Alzheimer’s disease is given by:
-A gradual onset “over months to years” rather than hours or days (the case with some other problems)
-A marked worsening of the individual person’s normal level of cognition in particular areas.
-The most common presentation marking Alzheimer’s dementia is where symptoms of memory loss are the most prominent, especially in the area of learning and recalling new information. But the initial presentation can also be one of mainly language problems, in which case the greatest symptom is struggling to find the right words.
-Finally, the most prominent deficits in “executive dysfunction” would be to do with reasoning, judgment and problem-solving.
Stages of Alzheimer’s disease
The progression of Alzheimer’s can be broken down into three basic stages:
Preclinical (no signs or symptoms yet)
Mild cognitive impairment
The Alzheimer’s Association has broken this down further, describing seven stages along a continuum of cognitive decline based on symptom severity – from a state of no impairment, through mild and moderate decline, and eventually reaching “very severe decline.”
The association has published the seven stages online. It is not usually until stage four that a diagnosis is clear – here it is called mild or early-stage Alzheimer’s disease, and “a careful medical interview should be able to detect clear-cut symptoms in several areas.”
Risk factors associated with Alzheimer’s disease include:
Unavoidable risk factors
Age – the disorder is more likely in older people, and a greater proportion of over-85-year-olds have it than of over-65s.
Family history (inheritance of genes) – having Alzheimer’s in the family is associated with higher risk. This is the second biggest risk factor after age.
Having a certain gene (the apolipoprotein E or APOE gene) puts a person, depending on their specific genetics, at three to eight times more risk than a person without the gene. Numerous other genes have been found to be associated with Alzheimer’s disease, even recently (see developments below).
Potentially avoidable or modifiable factors
Factors that increase blood vessel (vascular) risk – including diabetes, high cholesterol and high blood pressure. (These also increase the risk of stroke, which itself can lead to another type of dementia.)
-Low educational and occupational attainment.
-Prior head injury. (While a traumatic brain injury does not necessarily lead to Alzheimer’s, some research links have been drawn, with increasing risk tied to the severity of trauma history.)
-Sleep disorders (the breathing problem sleep apnea, for example).
Early-onset Alzheimer’s disease
Genetics are behind early-onset familial Alzheimer’s disease, which presents typically between the ages of 30 and 60 years and affects people who have a family history of it.
Due to one of three inherited genes, it is also known as young-onset, and it is uncommon – accounting for under 5% of all Alzheimer’s cases.
The Alzheimer’s Association says in its early-onset information that it can sometimes be “a long and frustrating process” to get this diagnosis confirmed since doctors do not expect to find Alzheimer’s in younger people. For the younger age groups, doctors will look for other dementia causes first.
Healthcare professionals, the nonprofit says, may also “incorrectly attribute” symptoms to stress and so on, or may not agree on the diagnosis.