Memory and Stroke Flashcards
(34 cards)
Human memory has 3 main types
sensory memory
short-term memory (working memory)
long-term memory (life-time)
two types of long term memory
explicit (conscious)
implicit (unconscious)
Procedural memory
unconscious recall of how to perform an action or skill (remembering how to ride a bike) type of implicit memory
episodic memory
involves context; must be learned all at once (remembering where you parked your car when you go into the grocery store) type of explicit/declarative memory
semantic memory
involves facts without context; facts for which the context does not matter (the sun is a star) can be acquired gradually over time; type of explicit/declarative memory
HM and the Hippocampus
HM had a seizure disorder; suffered from severe intractable epilepsy; had medial temporal lobectomy surgery to remove HIPPOCAMPUS AND AMYGDALA; after surgery: reduction of seizures, emotional stable and IQ increased BUT lost all memory
wrote in diary “today I woke for the first time”
Long term memory storage
memory peaks around age 8
reviewing/rehearsing materials
storage is not permanent for a few hours to day
Amnesia
partial or total loss of memory
2 types
anterograde amnesia
failure in explicit memory
declarative
information available to consciousness
failure of relational learning
cant form new memories
retrograde amnesia
failure in implicit memory
non-declarative
cant recall previous memories
stroke
occurs when something blocks blood supply to part of the brain or when a blood vessel in the brain bursts
~750,000/year
infarcts
tissue necrosis due to stroke
CVA
cerebrovascular accident
ischemic stroke
obstruct the flow of blood; can be caused by a thrombus or an embolus
~88% strokes
thrombus
blood clot in blood vessels; can be the cause of a ischemic stroke
embolus
a piece of material that breaks off and is carried through the bloodstream until it reaches an artery too small to pass through: can cause an ischemic stroke
hemorrhagic strokes
caused by bleeding in the brain
~12% of strokes
transient ischemic attack (TIA)
a stroke that lasts only a few minutes
1/3 will eventually have an actual stroke
50% within 1 year will have a stroke
initial damage in ischemic strokes d/t glutamate ecotoxicity
excessive glutamate is the immediate cause of neuron death
decreased O2 leads to neural membrane depolarization = high glutamate
NMDA receptors become overstimulated
inflammation attracts microglia
microglia attracts WBC that attach to the region
= cell death
stroke risk factors: non-modifiable
age
race
family history
stroke risk factors: modifiable
smoking
obesity
high blood pressure
alcohol
stress
circle of willis
where the internal carotid arteries branch into smaller arteries that supply oxygenated blood to over 80% of the cerebrum: on ventral part of the brain
Middle cerebral artery (MCA) stroke
90% of strokes
largest of the brain arteries
supplies most of the outer surface of the frontal, parietal, temporal lobes and basal ganglia
MCA stroke symptoms
contralateral weakness and sensory loss in UPPER EXTREMITIES
loss of vision
Left MCA strokes: speech deficits (Brocas and wernicke’s)
right MCA strokes: neglect and poor motivation (flat prosody)