Lecture 5 Flashcards
parts of the brain
• Cerebral cortex – outermost part of the brain connected by thick
network of neurons called corpus collosum
• Two hemispheres: left=language; right= emotion, facial
recognition
• Neurons, dendrites, axon, terminal branches, neurotransmitters
• Pre-frontal and frontal cortex - executive functioning - focus,
plans, switch tasks, decisions, etc
• Limbic system – where the mid brain meets the cerebral cortex –
partly responsible for emotion, motivation, long term memory, etc
• Hippocampus - middle of the brain – equilibrium and fine motor control
and memory
• Amygdala – deep in medial temporal lobe - partly responsible for emotion
what happens to the brain as they age
Decline in neurons • Decrease in size and number of dendrites • Development of tangles in neurofibres • Deposit of some proteins (beta amyloid for example) • Decline in cerebrovascular circulation (oxygen, glucose delivery)
changes in cognition as we age
• Lowered ability to focus
• Executive functioning decreases – inability to divert attention, switch
tasks, understand important parts of information (eg. in an article)
• Changes in memory – working and episodic
• Processing speed, language, recall, visuospacial activities
• Bilateral activation to compensate for lost cognition (young adults
have unilateral activation)
• Implications for exercise programs?
risk factors for cognitive changes with age
Diabetes • Smoking • High blood pressure • Elevated cholesterol • Obesity • Depression • Lack of physical exercise • Low education level • Infrequent participation in mentally or socially stimulating activities
mild cognitive impairment
• Stage between normal changes with age and pathological changes
• Can be beginning of chronic issue or brought on by medication, diet
changes, environmental changes (moving).
• Brain changes include some plaques and tangles, perhaps Lewy bodies
(another protein), small strokes or reduced blood flow, shrinking in
hippocampus, enlargement of ventricles and reduced use of glucose
dementia- umbrella term
• A group of symptoms that includes changes in memory, thinking and social interactions that would
interfere with daily activities. Most common neurodegenerative disorder.
• Caused by a loss of neurons in different parts of the brain which causes different symptoms
• Dementias are diagnosed based on the type of protein deposit or location in the brain where the
damage is located (Fronto-temporal dementia, Lewy body dementia…)
• May also have reversible changes caused by illness, infection, medication, brain tumors etc
• Age (over 65) and family history are risk factors
alzheimer’s disease
• Most common dementia
• 747,000 people in Canada are living with Alzheimer’s or another
type of dementia. This
number is expected to double in 20 years.
• Diagnosed in 5-7% of people 60+; 25-50% of those over 80
show symptoms
• Significant brain atrophy (loss of neurons) and plaques and
tangles present
is exercise good for the brain
• “physical exercise is a promising non-pharmaceutical intervention to
prevent age-related cognitive decline and neurodegenerative
diseases”
• Some results: in general, cross-sectional studies show that aerobic fitness is
associated with better cognitive function
• Longitudinal studies: physically active adults show less cognitive decline than
those who are sedentary
• Intervention studies: seniors who participate in a PA program that produces
significant CV improvement show enhanced cognitive performance
• Aerobic training seems to show the best results and includes healthy, frail and
adults living with MCI and dementia
to add to this
• Both psychological and social functioning contribute to
cognitive maintenance in older adults and physical activity
can assist in increasing both
• In other words, if we can reduce depression through the social aspect
of physical activity programs, cognitive health can be maintained in
older adulthood
exercise for those WITH cognitive impairment
• Improves stamina, mood, circulation, sleep, depression
• Improves calming effect – may decrease aggressive, wandering and repetitive behaviours
• Helps retain motor and communication skills
• Imparts sense of meaning, purpose, contribution to their own health
• Controls hypertension, falls and all other general benefits
• Brain improvements: increase activity in pre-frontal cortex, improve connections between prefrontal
cortex and parietal cortex,
• Research supports aerobic exercise helps counter the decline in the hippocampus
BDNF stands for
brain derived neurotrophic factor
BDNF
• Aerobic exercise creates this protein in the brain that improves cognition and
alleviates anxiety and depression
• “Regulation of Bdnf expression occurs by many means, but how exercise
influences the expression of trophic factors is not understood.”
neural plasticity
• the ability of the CNS to adapt or remodel itself in response to the
environment or to due to injury or other structural changes within
the brain itself
• may involve modifications in overall cognitive strategies to
successfully cope with new challenges (i.e., attention, behavioral
compensation), recruitment of new/different neural networks, or
changes in strength of connections or specific brain areas in charge of
carrying out specific tasks (i.e., movement, language, vision, hearing).
• changes in cell membrane excitability, synaptic adaptation, and
structural changes in dendrites and axons have been measured in
animals and humans
things to remember
- Routine is important
- Emotional outbursts may occur
- Constant supervision is required
- Simple exercises, simple cues
- Verbal and physical guiding may be required to remember movements
- Music may be helpful to relax
- Communication may be difficult especially in the later stages
- Incontinence and limited mobility are common
- Earlier in the day better as later sometimes causes more agitation
ACSM exercise prescription for Alzheimers
- Aerobic – familiar activities, enjoyment and function (walk)
- Goal is to increase functional health and ADL/IADL
- Increase endurance for community ambulation
- Focus on postural muscles and legs (10-12 reps as tolerated)
- Stretch postural muscles. Most should be done from a chair or raised platform
- TIME – aim for 40-60 minutes broken up to 15-20 min bouts. Monitor HR
- Increase active living choices and emphasize enjoyment over improvement
