29: Memory Impairment: Risk Factors

This program will:

  • Provide a basic understanding of how memory works and the different kinds of memory
  • Discuss some risk factors for memory loss and how they can interfere with normal memory functioning
  • There are no easy answer when its comes to the care of another
  • Our hope is to offer you useful information and guidelines for caring for someone with dementia
  • These guidelines will need to be adjusted to suit your own individual needs
  • Memory involves specialized areas of the brain, such as the hippocampus
  • Memory is subjective
  • People only store information that they are paying attention to
  • Nerve cells (neurons) form connections to establish pathways of information
  • Gray matter contains nerve cells that form the processing centers for the brain’s functions
  • White matter is formed by myelinated nerve fibers (axons)
  • Corpus callosum connects the left and right sides of the brain
  • There is a miniscule space between nerve cell connections called a synapse
  • When a signal in a nerve cell travels from the dendrite to the cell body and onto the end of an axon, chemicals called neurotransmitters are released
  • Neurotransmitters leave the axon and cross the synapse to get picked up by a dendrite of the next neuron
  • When enough neurotransmitters are picked up by the receiving nerve cell, it triggers a signal that travels down this new nerve cell to cause the release of new neurotransmitters
  • This cascade of nerve cell firing and neurotransmitter release is how nerve cells communicate
  • Action potential: signal that travel down the nerve cell
  • A complex pattern of action potentials through networks of nerve cells and pathways is how information is stored and transmitted in the brain
  • In Alzheimer’s disease, the brain produces less neurotransmitters, and nerve cell networks and pathways are damaged and lost
  • Memory is the ability to retain and recall information
  • Encoding: registering the information
  • Storage: creating a permanent record of the encoded information
  • Retrieval: calling back the stored information
  • Information is acquired and passed into short-term memory
  • Short term memory: recall for a period of several seconds to a minute without rehearsal
  • Rehearsal: repeated exposure
  • Memory consolidation: process by which recent or short-term memories are transformed into long-term memories
  • With continued rehearsal, or repeated firings between a network of nerve cells, the connections between them become stronger
  • System for temporarily storing and managing information
  • Where information is processed and manipulated so that learning, reasoning, and understanding can occur
  • Bridge between encoding, storing, and retrieving information
  • Used to bring information in and out of storage to manipulate it
  • Short-term memory is a type of working memory
  • Working memory has limited capacity
  • Memory span: number of items that a person can hold onto and recall
  • Many older people lose working memory capacity
  • Harder for older people to refocus when they are interrupted or distracted
  • Comprehension of speech declines with aging
  • The more rapid the speech and more complex the sentences, the more difficult it is for older people to understand what is being
  • Four types of memory retrieval
    • Recall:being able to access the information without being provided with any part of the memory
      • Answering fill-in-the-blank questions
    • Recollection: reconstructing a memory using pieces of memories, clues, logical structure, and narrative
      • Answering an essay question
    • Recognition: identifying information as a memory after experiencing it again
      • Answering multiple choice or matching questions
    • Relearning:relearning information that has been previously learned, which often strengthens the memory and makes it easier to remember and retrieve the information in the future
  • People tend to reorder, reconstruct and condense information to fit their own perception

Types of Memory

  • SENSORY MEMORY
  • Information that is received through the sensory organs
  • Iconic memory: brief mental picture after seeing something
  • Echoic memory: brief mental echo of a sound after it is heard

Types of Memory

  • EXPLICIT MEMORY PART-1
  • Declarative memory
  • Involves conscious, intentional recollection
  • Acquired knowledge and facts about the world, people, places, objects, and events
  • Episodic memory
  • Semantic memory

Types of Memory (continued)

  • EXPLICIT MEMORY PART-2
  • Episodic memory: memory of past events involving oneself that occurred at a particular time and place
  • Older people have loss of some episodic memory for experiences and events
  • Episodic memory loss can occur at any age with conditions such as sensory overload, depression, stress, or boredom

Types of Memory (continued)

  • EXPLICIT MEMORY PART-3
  • SEMANTIC MEMORY: memory of meanings, understandings, and other concept-based knowledge
  • Generic, context-free, encyclopedic knowledge that a person acquires over a lifetime about things information about words, what they mean, and how they are used
  • Aging is not associated with loss of semantic memories

Types of Memory (continued)

  • IMPLICIT MEMORY
  • Remembering things without being aware that you are remembering them
  • Automatic or an unconscious form of memory
  • Previous experiences help in performing a task, so that your performance improves with repetition
  • Procedural memory
  • Walking, tying shoelaces, dressing
  • Lost in the later stages of Alzheimer’s disease
  • SPATIAL MEMORY
  • Stores information about one’s environment and its spatial orientation
  • Declines with aging
  • Getting lost, missing steps, bumping into objects become potential hazards
  • Caregivers should try to de-emphasize the types of memories that are impaired, and try to exercise the person’s retained types of memories
  • Risk factor (predisposing factor): anything that increases the vulnerability for a condition
    • Risk factors for memory impairment
    • Family history
    • Lower education level
    • Older age
    • History of head trauma
    • Illness
    • Medications, including alcohol or illicit drugs
    • Vision or hearing impairment
    • Uncontrolled chronic medical conditions, such as congestive heart or kidney failure
  • Familial Alzheimer’s disease (FAD) or Early-Onset Alzheimer’s
    • If one parent has FAD, then the children have a 50/50 chance of developing it
  • Majority of Alzheimer’s disease cases are late-onset
  • No known cause
  • Several genes appear to increase the risk
    • Apolipoprotein E4 (ApoE4)
  • ApoE2 appears to decrease the risk of developing the disease
  • Learning and intellectual exercises may prevent or delay memory loss and the onset of Alzheimer’s disease
  • The brain loses nerve cells beginning in a person’s twenties
  • Aging is associated with a slowing of brain and body functioning
  • Brain noise increases with age, contributing to less efficient and less accurate information processing and performance among the elderly
  • Medical conditions that become more common with aging
    • Heart disease, strokes, high blood pressure, high cholesterol, diabetes, and hormonal imbalances.
    • Controlling these medical conditions is essential to reducing the risk of and memory impairment and Alzheimer’s disease
  • Aging can directly and indirectly affect memory through changes to the heart, blood vessels, lungs, kidneys, brain, and sensory systems
    • Inefficient circulation
      • Reduces brain functioning, which can cause forgetfulness and confusion
      • Fatigue decreases motivation and attention span
    • Poor lung function
      • Reduces oxygen to the brain
      • Damaging to brain cells
    • Decreased kidney function
      • Toxins can build up in the body and brain
      • Confusion and forgetfulness may be the first signs of kidney problems
      • Poor bladder control can affect attention
  • Decreased ability to maintain homeostasis of all the body systems
    • Decrease in immune response increases infections and delays healing and recovery
    • The longer an illness persists, the greater the negative effect on memory and other mental functions
  • Reduced vision and hearing
    • Limits ability to observe and understand the environments and activities occurring around them
    • Hinders learning
  • Aging itself does not reduce vocabulary and general knowledge, logical thinking, judgment, decision-making ability and other executive functions
  • Cautiousness, short attention span, loneliness and depression, poor motivation, indifference, and low self-esteem can affect memory
  • Loss of support systems (family and friends) can decrease confidence and self-esteem
  • Most frequently diagnosed mental illness in those over 65
  • Results in concentration difficulties and inattention to the environment , which can lead to memory problems
  • Causes of depression among the elderly
    • Medications and their side effects
    • Chronic illness
    • Chronic pain
    • Decline in the body’s mood elevating substances
    • Changes in body image, physical and mental abilities, careers
    • Loss of loved ones
    • Social isolation
    • Lack of support systems
  • Anxiety and stress decrease concentration and attention span
  • Excessive or chronic stress or anxiety impacts the body, mind, and behavior
  • Any illness that causes pain, discomfort, or fever can cause concentration and memory issues
  • Aging is associated with many chronic illnesses
  • History of severe head trauma increases the risk of memory problems and Alzheimer’s disease
  • Any condition that compromises the ability of the brain to function properly can cause confusion and memory difficulties
  • Drugs are a common cause of confusion and memory problems
  • Using combinations of drugs increases the risk of adverse drug reactions
  • Many medications can impair mental functioning
  • Drug withdrawal can cause dementia-like symptoms
  • Precipitating factor: an event or condition that elicits or contributes to the occurrence of a problem or to a critical decline of a condition
  • Physical trauma
  • Confusion the elderly following hip fractures or surgical procedures is a common occurrence
  • Personal or financial loss
  • Traumatic events can lead to confusion
  • Dehydration and malnourishment
  • Fluid retention and fecal impaction
    • Occur more frequently among the elderly, especially those with dementia
    • Should always be considered when confusion occurs
  • Hyperthermia
    • Overheating of the body can cause delirium and even permanent brain damage
  • Fever
    • Delirium at fevers around105 degrees F
  • Infection
    • Elderly can have limited ability to mount a fever response
    • Various mechanisms for causing delirium
  • Mild cognitive impairment (MCI): mental deficits that do not significantly interfere with functioning or daily life
  • Memory problems, slower thinking, and a reduced ability to learn
  • Can worsen to become Alzheimer’s
  • MCI appears to be a transitional state between normal memory and Alzheimer’s disease in some people
  • Preventing or treating MCI could be one approach to decreasing the risk of developing Alzheimer’s
  • Causes
  • Heart disease and chronic lung diseases (COPD-Chronic Obstructive Lung Disease)
  • Reduce oxygen to the brain
  • Kidney and liver diseases
  • Toxins damage the brain
  • Hormonal imbalances
  • Thyroid disease
  • Poor nutrition and vitamin deficiency
  • Vitamins and minerals are important for a healthy brain
  • Medications and substance abuse
  • Older people are more sensitive to adverse drug reactions
  • Without appropriate treatment, dementia that could have been improved or reversed may become irreversible
  • Avoid unnecessarily labeling someone
  • Forgetfulness occurs at any age and under many different circumstances
  • Memory formation and retrieval involves a complex process of signal transduction through a network of nerve cells and pathways
  • Information processing and storage requires attention and concentration
  • Main types of memory
    • Sensory
    • Explicit memory
      • Episodic memory and semantic memory
    • Implicit
    • Spatial
  • Aging is associated with a decline in most forms of memory, particularly working memory, which is needed for information analysis and speech comprehension
  • Semantic and implicit memories remain largely intact
  • Risk factors for memory impairment
    • Family history, lower education level, older age, history of head trauma, illness, medications, vision or hearing impairment, uncontrolled chronic medical conditions, and psychological factors
  • Precipitating factors
    • Physical trauma, personal or financial loss, dehydration, fluid retention, fecal impaction, fever, and infection
  • Mild cognitive impairment and reversible dementias can develop into irreversible dementia
  • Cause of reversible dementias
    • Chronic medical conditions, vitamin deficiencies, and medications
  • By controlling some of the known risk factors for memory impairment, it may be possible to prevent or limit memory loss

Written by:
Catherine M. Harris, PhD, RNCS.
Mindy J. Kim-Miller, MD, PhD

Edited by:
Sasha Asdourian

www.LightBridgeHealthcare.com

28: Nutrition

Select the best answers from the list of choices following each question.

Click here to open Certificate of Completion
  • Angevaren M, Aufdemkampe G, Verhaar HJ, Aleman A, Vanhees L. (2008). Physical activity and enhanced fitness to improve cognitive function in older people without known cognitive impairment. Cochrane Database Syst Rev. 16(3):CD005381.
  • Ashbrook PW, McDermott MJ, Kline JS, Hayden SR, & Land JW, (1986). Emotion and memory: Depressed mood states and memory for schematically organized events. Unpublished manuscript. University of New Mexico, Albuquerque, NM.
  • Brand-Miller, J; Volwever, TMS; Colaguiri, S; Foster-Powell, K. The glucose revolution. New York: Marlow; 1999.
  • Brown, A.S. (1991). A review of the tip-of-the-tongue experience. Psychological Bulletin, 109(2), 204-223.
  • Del Ser, T; Hachinski, V; Merskey, H; Munoz, DG. An autopsy-verified study of the effect of education on degenerative dementia. Brain.1999;122:2309–2319.
  • Ellis HC, McFarland AD, Christian KM & Thompson RF (2003). Neural substrates of eyeblink conditioning: Acquisition and retention. Cold Spring Harbor Laboratory Press.
  • Columbia University Medical Center (2007, March 20). New Reason To Hit The Gym: Fighting Memory Loss. ScienceDaily. Retrieved January 15, 2009, from http://www.sciencedaily.com /releases/2007/03/070320073516.htm.
  • Ellis H C & Ashbrook PW. (1987). Resource allocation model of the effects of depressed mood states on memory. In K Fiedler & J Forgas (Eds.) Affect, Cognition and Social Behavior. Hogrefe: Toronto.
  • Eriksson, J; Lindstrom, J; Tuomilehto, J. Potential for the prevention of type 2 diabetes. Br Med Bull. 2001;60:183–199.
  • Folstein, M; Folstein, S; McHugh, P. “Mini-mental state”: a practical method for grading the cognitive state of patients for the clinician. J Psychiatr Res. 1975;12:189–198.
  • Friedland, RP; Fritsch, T; Smyth, KA; Koss, E; Lerner, AJ; Chen, CH, et al. Patients with Alzheimer’s disease have reduced activities in midlife compared with healthy control-group members. Proc Natl Acad Sci USA. 2001;98:3440–3445.
  • Gage, FH. Neurogenesis in the adult brain. J Neurosci. 2002;22:612–613.
  • Higbee, KL, (1977). Your memory: How it works and how to improve it. Prentice-Hall, Inc. Inglewood Cliffs, New Jersey.
  • Joseph, JA; Nadeau, D; Underwood, A. The color code: a revolutionary eating plan for optimum health. New York: Hyperion; 2002.
  • Kandel ER, Schwartz JH, & Jessell TM, (1995). Essentials of neural science and behavior. Appleton and Lange. Stamford, Conn.
  • Kidd PM. (2008). Alzheimer’s disease, amnesic mild cognitive impairment, and age-associated memory impairment: current understanding and progress toward integrative prevention. Altern Med Rev. 13(2):85-115.
  • Kramer, AF; Hahn, S; McAuley, E; Cohen, NJ; Banich, MT; Harrison, C, et al. Exercise, aging and cognition: healthy body, healthy mind? In:Fisk AD, Rogers W. , editors. Human factors interventions for the health care of older adults. Hillsdale, NJ: Erlbaum; 2001.
  • Lautenschlager NT, Cox KL, Flicker L, Foster JK, et al. (2008). Effect of Physical Activity on Cognitive Function in Older Adults at Risk for Alzheimer Disease. JAMA. 300(9):1027-37.
  • Luria AR (1073). The working brain. Basic Books. New York.
  • Matser, JT; Kessels, AG; Lezak, MD; Jordan, BD; Troost, J. Neuropsychological impairment in amateur soccer players. JAMA. 1999;282:971–973.
  • Mattson, MP. Existing data suggest that Alzheimer’s disease is preventable. Ann N Y Acad Sci. 2000;924:153–159.
  • Mayeux, R. Gene-environment interaction in late-onset Alzheimer disease: the role of apolipoprotein-epsilon4. Alzheimer Dis Assoc Disord.1998;12(suppl 3):S10–S15.
  • Merchant, C; Tang, MX; Albert, S; Manly, J; Stern, Y; Mayeux, R. The influence of smoking on the risk of Alzheimer’s disease. Neurology.1999;52:1408–1412.
  • Morris, MC; Beckett, LA; Scherr, PA; Herbert, LE; Bennett, DA; Field, TS, et al. Vitamin E and vitamin C supplement use and risk of incident Alzheimer disease. Alzheim Dis Assoc Disord. 1998;12:121–126.
  • Newcomer, JW; Selke, G; Melson, AK; Hershey, T; Craft, S; Richards, K, et al. Decreased memory performance in healthy humans induced by stress-level cortisol treatment. Arch Gen Psychiatry. 1999;56:527–533.
  • Patel AK, Rogers JT, Huang X. (2008). Flavanols, mild cognitive impairment, and Alzheimer’s dementia. Int J Clin Exp Med. 1(2):181-91. Epub 2008 Apr 15.
  • Relkin, NR; Tanzi, R; Breitner, J; Farrer, L; Gandy, S; Haines, J, et al. Apolipoprotein E genotyping in Alzheimer’s disease: position statement of the National Institute on Aging/Alzheimer’s Association Working Group. Lancet. 1996;347:1091–1095.
  • Ruitenberg, A; van Swieten, JC; Witteman, JC; Mehta, KM; van Duijn, CM; Hofman, A, et al. Alcohol consumption and risk of dementia: the Rotterdam study. Lancet. 2002;359:281–286.
  • Sapolsky, RM. Glucocorticoids, stress, and their adverse neurological effects: relevance to aging. Exp Gerontol. 1999;34:721–732.
  • Schacter, D.L. (2001). The seven sins of memory: How the mind forgets and remembers. New York: Houghton Mifflin.
  • Shatenstein B, Kergoat MJ, Reid I, Chicoine ME. (2008). Dietary intervention in older adults with early-stage Alzheimer dementia: early lessons learned. J Nutr Health Aging. 12(7):461-9.
  • Silverman, DHS; Small, GW; Chang, CY; Lu, CV; Kung de Aburto, MA; Chen, W, et al. Positron emission tomography in evaluation of dementia: regional brain metabolism and long-term clinical outcome. JAMA. 2001;286:2120–2127.
  • Small GW. The memory bible: an innovative strategy for keeping the brain young. London: Penguin; 2002.
  • Small GW. What we need to know about age related memory loss. BMJ. 2002 June 22; 324(7352): 1502–1505.
  • Small, GW; Rabins, PV; Barry, PP; Buckholtz, NS; DeKosky, ST; Ferris, SH, et al. Diagnosis and treatment of Alzheimer disease and related disorders: consensus statement of the American Association for Geriatric Psychiatry, the Alzheimer’s Association, and the American GeriatricsSociety. JAMA. 1997;278:1363–1371.
  • Solfrizzi, V; Panza, F; Torres, F; Mastroianni, F; Del Parigi, A; Venezia, A, et al. High monounsaturated fatty acids intake protects against agerelated cognitive decline. Neurology. 1999;52:1563–1569.
  • Van Praag, H; Kempermann, G; Gage, FH. Neural consequences of environmental enrichment. Nat Rev Neurosci. 2000;1:191–198.
  • Woodruff-Pak DS & Thompson RF. (1985). Classical conditioning of the eyelid response in rabbits as a model system for the study of brain mechanisms of learning and memory in aging. Experimental Aging Research 11(2) p109-119.

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