Module 6.2 Flashcards
Life Expectancy
•There are certain genetic characteristics that centenarians (people who are 100 years old) have in common that appear to promote longevity while at the same time interfering with disease processes such as cancer.
Why do we age? Theories:
Wear and Tear Theory:
-The human body, like a machine simply wears out over time because of the accumulated stress placed on it.
Accumulation of Waste Theory
- Metabolic waste products accumulate and cause deterioration and death of cells. Examples include cholesterol build up in the arteries, and cataracts.
- Cells have a limited number of divisions that they can undergo before they are no longer able to divide and then contribute to waste (“cellular senescence”)
Biological Clock Theory
-Our genes act as a genetic clock; they pre-program us to only live for a certain amount of time.
Immune Theory
-One theory states that the ability of the immune system to respond to foreign substances diminishes with age, contributing to greater susceptibility to disease.
Gene Theory
-There is a theory that certain genes are actually responsible for producing the changes and decline that we associate with aging.
Free Radians:
-Are the product of interaction between oxygen and mitochondria in cells. These are theorized to contribute to cell death and aging process over time.
Prevalence of disability/ injury
• Prevalence of disability for young seniors has been declining
• Significant rises in disability are not noticed until after 75
• Rate of accidental death and injury leading to hospitalization is 3 times greater than at any other age. Risk of disability is increased because of:
>Slower reaction time
>Less muscle mass
>Decrease in sensory acuity
• Some suggest that the old are getting younger. For example, some suggest that today’s 70 year old is more like a 50 year old of 20 or 30 years ago.
• Even after the age of 85, disability is only reported by ½ of all seniors. Cognitive impairment is only reported by 9% of seniors after age 85.
•While women live longer, the presence of disability is greater for older women than for older men.
>For example, while aging men are also susceptible to osteoporosis, by the age of 70, females have commonly lost 30% of bone calcium. A significant problem is hip fractures, with 20% of elderly people dying within a year of fracture and 50% experiencing chronic disability.
• Even by age 85, only ½ of seniors self report disability
• Significant cognitive impairment is not a part of the “normal” aging process, and if it occurs, may be due to a variety of factors other than brain deterioration
Aging skin
Eccrine glands
- Any of the numerous small sweat glands distributed over the body’s surface that produce a clear aqueous secretion devoid of cytoplasmic constituents and important in regulating body temperature.
- In aging skin: The number of eccrine glands is reduced. Thus, aging appears to reduce the effectiveness of sweating as a mechanism to cool the body.
Skin
- In addition, both epidermis and dermis undergo a thinning process during later maturity.
- Dermis loses about 20% of thickness, along with depletion of subcutaneous fat.
- Walls of blood vessels undergo thinning as well.
- All of this contributes to making older person more susceptible to temperature variations. In addition, the older person’s skin is more susceptible to bruising and tearing.
Elderly and prescriptions
• People over the age of 65 are given ¼ of all prescribed medications.
• Elderly people do not metabolize drugs as efficiently. They are 2 – 7 times more likely to suffer adverse side effects.
•When research is done on drugs, it’s very rare that companies conduct research on elderly. These drugs are formulated for young healthy adults. This is why elderlies don’t react as well to meds.
•Age can affect the body’s ability to metabolize and eliminate medications:
>E.g. a person at 70 takes twice as long as someone at 50 to eliminate antianxiety medications from his or her system.
• If the half life of a medication for younger persons it is about 45 hours, then for someone who is 70 or older it is about 90 hours (see next slide for definition of half life)
• The liver isn’t as efficient at metabolizing and kidneys are as efficient at excreting.
• In some cases where older persons receive sedatives a paradoxical effect may be noticed, such that the person becomes agitated rather than sedated. This is due to changes in how medications are processed.
•Half-life: The amount of time it takes for half of a dose of medication to be eliminated from the body: it is measured by when the medication concentration in the blood plasma reaches half of the concentration at initial dosing.
Polypharmacy
- The term “polypharmacy” is used to describe the prescription of multiple medications to one individual.
- Often specifically defined as 4 or more or 5 or more medications
- Usually understood to be in persons 65 years and older
- Nearly 50% of older adults take one or more medications that are not medically necessary. Research has clearly established a strong relationship between polypharmacy and negative clinical consequences
Define: Presbycusis Lentigo senilis Cataract Ageism Crystallized intelligence Fluid intelligence Senescence Osteoporosis Exit events
Presbycusis: Progressive loss of hearing and sound discrimination, particularly for consonants and high frequency sounds
Lentigo senilis: Large freckles that are associated with aging (“age spots”). Commonly found on backs of hands, arms and face.
Cataract: The condition that occurs when the lens of the eye becomes opaque or cloudy and produces diminished vision and increased sensitivity to glare.
Ageism: Discrimination against individuals on the basis of age, inferring that elderly people are inferior to those who are younger.
Crystallized intelligence: Knowledge and cognitive ability that are maintained over the lifetime. It includes problem-solving, wisdom, judgment, and generally, knowledge and abilities that have been reinforced by practice/experience, education, and opportunity for demonstration.
Fluid intelligence: Intelligence that is largely innate and independent of education and experience; includes good short term memory, ability to acquire new information comparatively easily; and speed.
Senescence: Mental and physical decline associated with the aging process.
Osteoporosis (porous bones): A condition in which bones are brittle, fragile and prone to fracture. More prominent in postmenopausal women and persons who are Caucasian, Asian, or of small stature (persons with Down syndrome are prone to osteoporosis)
Exit events: Losses experienced by older persons that signify closing out of life. The accumulation of such losses can lead to loneliness and depression for some persons: loss of job through retirement, loss of long-time spouse, loss of driver’s licence, movement into personal care home, etc.
Other Health Issues
Elderly people commonly experience a sudden reduction in blood pressure when standing up quickly, this can lead to fainting.
This is often referred to as “postural” or “orthostatic” hypotension
The elderly may often experience drops in blood pressure after eating or taking a hot bath.
There is evidence of an increased rate of depression after the age of 75. One explanation is the increased weight of accumulated losses or EXIT events.
Dementia
- Dementiais a general term that refers to a variety of brain disorders that cause permanent physical changes in the brain.
- Dementia is often associated with eventual cognitive decline and impairment of functioning.
- Not to be confused with Delirium which is a temporary and reversible state even though they both can present in similar ways.
- Is diagnosed when a person has multiple cognitive deficits including memory impairment & one or more of the following: Aphasia, Agnosia, Apraxia, Disturbance in executive functioning
- Dementia does not necessarily mean “continuing decline” or “irreversibility”, though many of the conditions that cause dementia are progressive degenerative diseases.
- Can be the result of a medical condition – Alzheimer Disease, AIDS, Huntington’s, head injury, Parkinson’s disease – or from persisting effects of exposure to toxic substances – alcohol, or some combination.
Symptoms:
- Memory impairment can be for new learning and/or previously formed memories.
- Person will have difficulty with complex tasks (sequencing behaviours)
- Poor sense of spatial relationships is common
- Insight is usually poor to nil
- Judgment is also markedly impaired
-Reasoning ability is affected so individuals have difficulty with problem solving
>Eventually people become unable to deal with new situations.
Define: Aphasia Agnosia Apraxia Executive Functioning Neurofibrillary tangle Amyloid plaques
Aphasia – impaired or absent comprehension or production of speech
Agnosia – inability to recognize or comprehend meaning of various sensory stimuli
Apraxia – impairment of skilled or purposeful movement; psychomotor deficit where the person can’t carry out the proper use of the object although they know what it is and what it is supposed to do
Executive functioning –think abstractly, to plan, initiate, sequence, monitor & stop complex behaviour
Neurofibrillary tangles are twisted protein fragments that accumulate inside nerve cells. They are one of the characteristic structural abnormalities found in the brains of patients with Alzheimer disease.
Amyloid plaques are sticky buildup which accumulates outside nerve cells, or neurons. Amyloid is a protein that is normally found throughout the body. For reasons as yet unknown, in AD, the protein divides improperly, creating a form called beta amyloid which is toxic to neurons in the brain.
-Plaques begin to form that consist of these degenerating neurons and clumps of the amyloid protein itself. The body cannot break these clumps down and dispose of them, so they accumulate in the brain
Alzheimer’s Disease
- AD is a progressive, degenerative, irreversible dementia
- Damage increases and can’t be repaired
- Symptoms: Progressive Loss of memory, Loss of judgment & reasoning, Changes in mood and behaviour
- Approximately 5-10% is familiar caused by a gene mutation (early onset)
- It is believed to be caused by the death of neurons & disruption of neurotransmitters
- Also involves neurofibrillary tangles & beta-amyloid plaques. “plaques,” which are numerous tiny, dense deposits scattered throughout the brain that become toxic to brain cells at excessive levels, and “tangles,” which interfere with vital processes, eventually choking off the living cells. When brain cells degenerate and die, the brain markedly shrinks in some regions
- disease leads to nerve cell death and tissue loss throughout the brain. Over time, the brain shrinks dramatically, affecting nearly all its functions.
- ventricles grow larger, sulci are noticeably widened and there is shrinkage of the gyri
There are two different types of Alzheimer’s:
Sporadic
Familial Autosomal Dominant
Sporadic
- 90-95% of cases are Sporadic
- Usually occurs after 65
- May or may not be a family history
- No single cause identified, but some proposed causes are: slow viruses, problems with immune system, chemical imbalances, head injury, environmental pollutants
Familial Autosomal Dominant
-Associated with several chromosome sites:
>Chromosome 1, with age of onset between 40-85
>Chromosome 14, with onset between 28-65
>Chromosome 21, with onset between 45-65
-While there is a 50% chance of inheriting the disease associated gene, expression likely depends on a “trigger”. This suggests that not all persons who have the gene will necessarily develop AD.
Variations in Alzheimer’s
- can span 3 – 20 years, with the average length of the disease between 8 – 12 years.
- the order in which symptoms appear, and the length of each stage will vary.
- About twice as many women as men have AD or a related dementia
Testing for Alzheimer’s Disease
- Only way to know for certain is a brain autopsy after death
- There is no definitive clinical test for Alzheimer disease.
- Therefore, a series of tests is used to rule out treatable causes of dementia.
- The basic workup consists of a thorough history and physical examination and a cognitive screening test such as the Mini-Mental State Examination (MMSE), the Montreal Cognitive Assessment (MoCA) or the Blessed Dementia Scale.
Diagnosing / Treatment Alzheimer’s
Diagnosis:
-Although Alzheimer’s disease can be diagnosed definitely only at autopsy (even here, 11% of dementias cannot be categorized despite microscopic examinations), the diagnostic accuracy of the National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer’s Disease and Related Disorders Association (NINCDS-ADRDA) criteria is as high as 85% to 90%.1
Treatment:
- No treatment can stop AD. However, for some people in the early and middle stages of the disease, the drugs tacrine (Cognex), donepezil (Aricept), rivastigmine (Exelon), or galantamine (Reminyl) may help prevent some symptoms from becoming worse for a limited time.
- These drugs help some people function better in daily activities such as bathing and eating, and may improve memory, language and other cognitive abilities.
Definitions of Death
-the irreversible cessation of vital functions, especially as it involves brain activity
