cognitive impairment and dementia Flashcards
what is dementia
set of symptoms including loss of memory, mood changes, problems communicating etc
what is the most common type of dementia
alzheimers disease (AD)
what term describes dementia gradually getting worse
progressive
what are some examples of origins of dementia
-degenerative e.g alzheimers
-vascular e.g multi infaret dementia
-toxic = alcohol related dementia
-metabolic/endocrine origins
what is AD
progressive, neurodegenerative
early mild symptoms of AD
-lapses of memory/ confusion
-repetition, problem finding words
-decisions are hard
-loss of interest in people and new ideas
-blame others for mislaid items
middle/ moderate symptoms of AD
-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
late/ severe symptoms of AD
-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
what is carried out to diagnose AD
looking into patient history
cognitive tests
physical examination eg blood tests
brain scans
what causes AD
-there is no single cause
-factors include: age, genetics, environment, lifestyle, general health
what kind of studies help disentangle causes of AD
twin studies, particularly MZ twins raised apart (steves et al 2012)
what neural indicators/ markers do researcher tend to focus on now
-neurodegenerative and progressive changes to plaques and tangles (amyloid and tau)
-reduction in neurotransmitters (acetylcholine, glutamate, GABA etc)
what protein forms plaques and tau
plaques = amyloid
tangles = tau
what is the amyloid cascade hypothesis
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
what does Aβ mean
amyloid peptide
NFT =
neurofibrillary tangles
what is a weakness of the amyloid cascade hypothesis
-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
what is the cholinergic hypothesis
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)
how does the cholinergic hypothesis (bowen et al) link to plasticity
-excess of Aβ prevents efficient receptor binding so less neural flexibility present (Lombardo and Maskos 2015)
where do AD treatments often target
ACh receptors
what neurotransmitters does ACh mediate the release of and what do they do
glutamate: plasticity, memory
GABA: attention, inhibiting irrelevant info
what neurotransmitter regulates ACh
dopamine: which is involved in problem solving, motivation, episodic memory etc
age as a risk factor of AD
-greatest risk factor
-factors assosciated with ageing are:
–higher BP
–increased chance of heart disease
–changes to nerve cells and immune system etc
genetics as a risk factors of AD
-APOE e4 allele increases risk of AD
-earlier onset by 14%