Alzheimer's Disease, Dementia, and Delirium Flashcards
The focus of delirium care is
prevention and reserved for those that will harm themselves or others
*medication in delirium has been known to increase risk of death
Cognitive Impairment
A deficit in cognitive function (memory, ability to reason, planning, attention, language, executive function, visuospatial perception)
Mild cognitive impairment
A drop from a prior level of cognitive function
*Cognitive function declines with age
**If a scientific study does not measure a prior level of function, an MCI cannot be defined
Dementia
Mild cognitive impairment plus the loss in the ability to care for one’s self
This includes activities of daily living: Eating, bathing, grooming, toileting, transferring and cooking
MCI Medication treatment vs Dementia
MCI not treated with any medication
Dementia can be treated with medications
Risk Factors of Dementia
Genetics (Apolipoprotein E variants e2, e3 and e4; single copy of e4 increases risk by 3 fold while homozygous copy of e4 increase by 8-12 fold; family history of CV also increases risk)
Cardiovascular Disease in Middle Age (Smoking, midlife obesity, midlife hypertension, midlife hyperlipidemia, diabetes)
Mild cognitive impairment will increase risk of dementia; Education and social interaction increase cognitive reserve
Most common form of dementia
Alzheimer’s Disease (60-80%)
In normal aging, neurons are ________, brain mass is ________ and synaptic connections are __________.
Preserved, Preserved, Lost
Result is slowed retrieval of memories but no impairment of storing them
Thinking and reasoning are preserved
Early Alzheimer’s
Hippocampus (memory) is affected early
No language affect
Ventricles begin to enlarge and sulci get wider as more cells die
Progression of Alzheiemer’s (general)
Memory first, followed by language and then reasoning/understanding, lastly is dis-inhibition and behavior problems
*the areas affected are rich in cholinergic neurons
Histology of Alzheimer’s
Amyloid beta peptide abnormally fold, causing insoluble plaques that accumulate on the outside of cells
Amyloid beta (A-beta) protein formation
Amyloid Precursor Protein (APP) cleaved by b-secretase then by y-secretase to give Amyloid-beta(42) which is highly plaque forming due to insolubility
When APP is cleaved by a-secretase instead, it gives rise to b-amyloid 40 which is more soluble and less plaque forming
Neuronal cell bright parts (Tau proteins)
Hyperphosphorolated tau proteins represent the bright parts and work to stabilize microtubules
Microtubules transport molecules and nutrients within the cell, axon and dendrites
Cholinergic Hypothesis
Loss of cholinergic neurons is responsible for AD (considered a downstream event)
Amyloid-Beta Hypothesis
A-beta is the initial pathology leading to inflammation and neuronal death
*Almost all adults have A-beta and A-beta load does not correlate with AD symptoms
Tau Hypothesis
Tau-hyperphosphorylation and neurofibillary tangles is the single common pathway that leads to AD
*this hypothesis is gaining ground
Inflammation Hypothesis
Inflammation is common inn AD; Nonspecific inflammation damages neurons causing A-beta and NFT
*many believe this to be a marker of neuronal damage rather than a cause
The novel hypothesis
Impaired glucose transport (brain uses 20% of body’s energy and is only 2% of it’s weight) > Disruption of energy formation can lead to oxidative stress, free radicals, inflammation and neuronal death > insulin resistance (diabetes) and decreased brain blood flow (vascular disease)