cognitive impairment and dementia

Question 1

what is dementia

Answer 1

set of symptoms including loss of memory, mood changes, problems communicating etc

Question 2

what is the most common type of dementia

Answer 2

alzheimers disease (AD)

Question 3

what term describes dementia gradually getting worse

Answer 3

progressive

Question 4

what are some examples of origins of dementia

Answer 4

-degenerative e.g alzheimers
-vascular e.g multi infaret dementia
-toxic = alcohol related dementia
-metabolic/endocrine origins

Question 5

what is AD

Answer 5

progressive, neurodegenerative

Question 6

early mild symptoms of AD

Answer 6

-lapses of memory/ confusion
-repetition, problem finding words
-decisions are hard
-loss of interest in people and new ideas
-blame others for mislaid items

Question 7

middle/ moderate symptoms of AD

Answer 7

-frequently confused, disorientated, forget names etc
-mood swings
-scared/ frustrated by memory loss
-withdrawal and loss of confidence
-difficulty carrying out everyday activities and need help with daily care

Question 8

late/ severe symptoms of AD

Answer 8

-totally dependent on others for care
-pronounced memory loss e.g cant remember close family
-increasingly frail, more falls etc
-difficulty eating = weight loss
-incontinence
-loss of speech
-aggressive/ distressed

Question 9

what is carried out to diagnose AD

Answer 9

looking into patient history
cognitive tests
physical examination eg blood tests
brain scans

Question 10

what causes AD

Answer 10

-there is no single cause
-factors include: age, genetics, environment, lifestyle, general health

Question 11

what kind of studies help disentangle causes of AD

Answer 11

twin studies, particularly MZ twins raised apart (steves et al 2012)

Question 12

what neural indicators/ markers do researcher tend to focus on now

Answer 12

-neurodegenerative and progressive changes to plaques and tangles (amyloid and tau)
-reduction in neurotransmitters (acetylcholine, glutamate, GABA etc)

Question 13

what protein forms plaques and tau

Answer 13

plaques = amyloid
tangles = tau

Question 14

what is the amyloid cascade hypothesis

Answer 14

Hardy and higgins 1992
-plaques and tangles cause onset of AD
-plaques surround neurons and tangles are inside soma
-abundance of amyloid causes tau tangles that are neurotoxic, causes neuronal cell death and dementia

Question 15

what does Aβ mean

Answer 15

amyloid peptide

Question 16

NFT =

Answer 16

neurofibrillary tangles

Question 17

what is a weakness of the amyloid cascade hypothesis

Answer 17

-mere presence of amyloid does not mean AD as healthy adults also have amyloid and tau deposits, its the excess if these that potentially leads to AD

Question 18

what is the cholinergic hypothesis

Answer 18

Bowen et al 1976
-evidence for neurotransmission and AD
-acetylcholine (ACh) links to arousal, memory and attention (these all decline in people with AD)
-ACh has widespread projections from basal forebrain influencing activity in rest of brain (including hippocampus)

Question 19

how does the cholinergic hypothesis (bowen et al) link to plasticity

Answer 19

-excess of Aβ prevents efficient receptor binding so less neural flexibility present (Lombardo and Maskos 2015)

Question 20

where do AD treatments often target

Answer 20

ACh receptors

Question 21

what neurotransmitters does ACh mediate the release of and what do they do

Answer 21

glutamate: plasticity, memory
GABA: attention, inhibiting irrelevant info

Question 22

what neurotransmitter regulates ACh

Answer 22

dopamine: which is involved in problem solving, motivation, episodic memory etc

Question 23

age as a risk factor of AD

Answer 23

-greatest risk factor
-factors assosciated with ageing are:
–higher BP
–increased chance of heart disease
–changes to nerve cells and immune system etc

Question 24

genetics as a risk factors of AD

Answer 24

-APOE e4 allele increases risk of AD
-earlier onset by 14%

Question 25

model for biological risk factors

Answer 25

alteration in Aβ OR normal Aβ, APOE e4 OR just ageing

lead to…

Aβ aggregation and accumulation

leading to…

toxicity
neuronal cell death
dementia

Question 26

environmental risk factors of dementia

Answer 26

-pollution: Chen et al 2017
–pollution is “cause” of 11% of dementia cases

-medical history/health: diabetes, obesity, strokes increase risk
–Lindsay et al 2002: physical exercise has protective function

-social activity: socially active people have slightly reduced chance of dev dementia
– Hsiao et al 2014: interaction reverses mem decline in mice

-mental activity: Baumgart et al 2015
–reading, learning, puzzles mean people less likely to dev dementia

Question 27

what is mild cognitive impairment (MCI)

Answer 27

-presence of acquired cog abnormality greater than expected in relation to age and education
-in the absence of dementia
-in the absence of detrimental daily effects upon daily living

Question 28

what % of people over 65 have MCI

Answer 28

5-20% (primary amnesic MCI)

Question 29

what are the 3 types of MCI

Answer 29

1.amnesic MCI = memory related dysfunction
2.amnesic multi domain MCI = impacts mem and other cog aspects
3.non amnesic MCI = influences many cog aspects but not memory

Question 30

characteristics of MCI

Answer 30

-can be transitory (for short time), normal cog function may return to normal
-for some it may be permanent: function does not return to normal, cog declines do not progress much, no dementia development
-only for some MCI represents early stages of AD

Question 31

what is the diagnostic criteria for MCI

Answer 31

-subjective decline in STM or LTM (can be determined by someone else)
-objective decline from age and education appropriate mean scores on cog tests
-preserved daily living (Albert 2011)

Question 32

what would a memory clinic include

Answer 32

-lab tests e.g bloods
-MRI scan
-family/ health history
-medical examination

Question 33

what are the issues diagnosing MCI

Answer 33

-subtle changes to memory, planning, lang, sensory perception etc which is often the case for general ageing so hard to tell the difference
-indiv diff not readily taken into account
-insensitivity of current neuropsychological tests and neuroimaging/ biomarkers (tests not sensitive enough to detect small changes)
-hearing/ visual damage may mean test is not fully understood so pp wrongly diagnosed
-performance dependent on day so could lead to wrong/missed diagnosis

Question 34

MCI and early signs of dementia

Answer 34

-for 15% MCI is prodromal stage of dementia
-risk factors effecting AD can also lead to MCI
-secondary ageing factors may influence MCI

Question 35

research on the fornix

Answer 35

Metzler and Baddeley 2012
-fornix is 4 white matter tracks with links to episodic memory in brain
-pp with MCI had volume loss in fornix
-shift in memory load/processing resources from fornix to parahippocampul cingulum

Question 36

what makes it hard to distinguish MCI patients

Answer 36

alternate pathways due to compensation means performance is quite high so hard to distinguish MCI patients

Question 37

Metzler and baddeley et al 2013 finding

Answer 37

larger BMI associated with greater loss of integrity in the fornix

Question 38

why is early identification best

Answer 38

-memory complaints may be associated with later dev of MCI/ AD
-jessen et al 2014: concerns regarding memory impairment predict dementia onset 6yrs later
-early identification means support can be put in place