Lecture 15+16 Flashcards
declarative (explicit) memory
facts and events
procedural (implicit) memory
skills/habits
conditioning
Episodic Memory
Personally experienced events within a spatiotemporal context
stages of memory
encoding - consolidation - retrieval
sensory input…. sensory memory… encode… short-term or working memory…. consolidate to long term memory
rehearsal (Helps in long term memory) and forgetting
retrograde and anterograde amnesia
retrograde: forgetting past memories
anterograde: cant form new memories
infantile amnesia
early childhood events cannot be remembered
transient global amnesia
typically occurs in older men
recent events and recent info can only be remembered for a few minutes
could be due to TIA, basilar A migraine, physical/psych stress
Dissociative amnesia
A psychological reaction to a major stressor
Wernicke-Korsakoff amnesia (diencephalic amnesia)
caused by thiamin deficiency in patients with alcohol abuse
symptoms include:
confusion, confabulation, and severe memory impairment
The Hippocampal Trisynaptic Circuit
- dentate gyrus
- CA3 pyramidal cells
- CA1 pyramidal cells
this is the pathway that generates synaptic plasticity
delirium
A delirium is a disturbance in the level of
consciousness
deficits in awareness and attention
have at least one cognitive disturbance
(deficit in memory/language, delusions)
sudden onset of symptoms
will fluctuate during the day
symptoms will start over overs to days
must be due to a physiological cause
(no intoxication)
typical clinical presentation of delirium
hyperactive (increased psychomotor activity, mood liability, agitation)
hypoactive (reduced psychomotor activity, lethargic)
sleep-wake disturbances
etiology of delirium
multiple: it could be from dehydration, fever, UTI
widespread brain regions impacted
deficient:
Central cholinergic functioning
Reticular Activating System and its ascending connections (important for attention and arousal)
risk factors and course of delirium
risk:
poor health or older age (non-modifiable)
immobilization, poor sleep, benzo use (modifiable)
course:
symptoms go until cause is reversed
resolution can take 3-7 days
amnesia for events during episode is common
results in longer ICU stays and poor long-term survival
treatment for delirium
treat the underlying medical condition
manage the symptoms
can use antipsychotics or benzos
use benzos caused by alcohol withdraw
use environmental supportive factors
A dementia
Refers to multiple and severe cognitive impairment without impaired consciousness
Is usually progressive and irreversible
Most commonly occurs in the elderly
Alzheimer’s Dementia (AD)
Significant memory impairment plus impairment in at least 1 other cognitive domain
a gradual onset with a steady progressive decline
exclusion of other causes such as stroke
neuropathology of AD
neuroanatomical:
cortical atrophy
hippocampal atrophy
enlarged ventricles
neurochemical:
multiple neurotransmitter deficiencies
loss of cholinergic neurons
neurofunctional: posterior hypometabolism (parietal/temporal)
histopathological:
ß-amyloid plaques and neurofibrillary tangles
biomarkers: CSF amyloid and tau levels
PET imaging of plaques
definitive diagnosis still depends on post-mortem confirmation
AD treatment
cholinesterase inhibitors:
donepezil
galantamine
rivastigmine
NMDA receptor:
memantine
AD drugs are considered ineffective
side affects: hypotension / GI
non-pharm methods
antipsychotics
anticonvulsants and antidepressants
