Path IV Flashcards
HIE
hypoxic ischemic enecephalopathy
HIE initially attacks what part of brain
grey matter
why is brain so sensitive to hypoxia
no energy stores
O2 and glucose supplied by circulation
what happens with reperfusion of ischemic event in brain
intracell edema
vascular injury
interstitial edema
release of intracellular vasoactive matabolites
how long of ischemic event till neuronsbegin to die
4-5 minutes
5+ minutes of global ischemia in brain leads to
thalamic and brain stem damage
what part of neuro system is more resistant to hypoxia
spinal cord
what are anoxic neurons
shrunken eosinophilic cytoplasm and pyknotic nuclei
what causes anoxic neurons
ischmia more than 4 minutes
what is Tx for anoxic neurons
reperfusion
what is neuronophagia
anoxic neurons surrounded by microglial cells
what are red neurons
dead neurons
if patient dies shortly after ischemia what will micro brain look like
normal because the reperfusion causes problems
reperfusion edema can be seen where clinically
papilledema
what is gliosis
process of CNS scarring from astrocytes
alzheimer type II astrocytes
hepatic encephalopathy
large nuclei and large vacuoles on H&E stain
GFAP stain
astrocytes
what cells are very sensitive to HIE
CA1 of hippocampus
layters 3,5,6 neoCx, purkinje cells, striatal neurons
diffuse cortical thalamic or combine neuronal loss in HIE results in what
dementia
vegetative state
damage to brainstem cause what
brain death
why are certain ares for susceptible to HIE
areas with neurons that produce more glutamate
what cells are in CA1 of hippocampus
purkinje
holzer stain
can see hippocampal sclerosis
if lose CA1
memory problems
what supplies CA1
anterior temporal branch posterior cerebral artery
what occurs in nonperfused brain after HIE
cerebral autolysis
blank on radionucletotide scan
what else gets damaged in severe HIE
glial cells also damaged
what converts selective neuronal necrosis to total tissue necrosis in brain
lactic acidosis
what is cerebral infarction
focal brain necrosis from complete and prolonged ischemia that focally affects all tissue elements, neurons, glia and vessels
what are the parts of an infarct
the core where there is dense ischmia( non revivable)
and the penumbra (moderate ischmia, delayed infarction GIVE O2!)
what is a blan infarct
swelling and disintegration of area
what is a hemorrhagic infarct
disintegration of lesion from an embolus/ thrombus with reperfusion of blood into affected area 10% time
what are lacunar infarcts
cystic cavities from previous hemorrhagic bleeds
what are common causes of cerebral infarcts
atherosclerosis
atherosclerosis with thrombus formation
small vessel disease
embolism
what are the small vessel disesases
HTN, DM, age, cerebral amyloid angiopathy
if see pink thickening around vessels, do what stain
congo red to rule out amyloid
small vessel disease usually result in what type cerebral infarcts
lacunar and hemorrhagic bleeds
what aa supply basal ganglia area
lenticulate striate off of middle cerebral
what areas does the anterior choroidal a supply
medial globus pallidus, post limb internal capsule, tail caudate and optic tract
man in barrel syndrome
watershed infarcts
where are the watershed areas
ACA-MCA MCA-PCA
what cause watershed infarcts
severe drops in BP
hypovolemia like GI bleed
what type of watershed is caused by sudden occlusion of internal carotid a or carotid stenosis
ACA-MCA
both fed by int carotid
clinical Sx watershed infarct
proximal arm and leg weakeness
can cause transcortical aphasia synrome
when does liquefaction take place after ischemic stroke
3 weeks
when do you see distinct border for necrosis on gross specimen of ishcmic stroke
2-10 days
microscopic brain 24 hr post ischemic stroke
red neurons
48 hrs microscopic post ischemic stroke
neutrophils
gliosis time frame post ischemic stroke
1-2 weeks
when does hemorrhagic conversion or evolutions occur after 5-10% ischemic strokes
within first week
