Part dos 0425FA Flashcards
damage to watershed zones
in severe hypotension.
upper leg/arm weakness.
defects in higher order visual processing.
what drives cerebral perfusion?
PCO2 (vessels dilate when PCO2 increases).
also affected by severe hypoxia.
tx of acute cerebral edema (stroke, trauma)
decrease ICP via therapeutic hyperventilation (decrease PCO2)
MCA stroke
- motor: contraparalysis of face and upper limb.
- sensory: contra loss of sensation of face and upper limb.
- Broca
- Wernicke
*if damage to nondominant (right) hemisphere - get hemineglect (of left side)
ACA stroke
- motor: contra paralysis of lower limb
2. sensory: contra loss of sensation of lower limb
lateral striate artery stroke
striatum, internal capsule: contra hemiparesis/hemiplegia.
common location of LACUNAR INFARCTS secondary to unmanaged HTN.
AComm lesion
saccular (berry) aneurysm.
impinge on cranial nn.
sx: visual field defects
PComm lesion
saccular (berry) aneurysm.
CN III palsy - eye is DOWN and OUT.
what is most common site for saccular (berry) aneurysm?
anterior communicating artery
what is most common complication of saccular (berry) aneurysm?
rupture leading to hemorrhagic stroke or subarachnoid hemorrhage
what is saccular (berry) aneurysm assoc. with?
- ADPKD
- Ehler Danlos syndrome
- Marfan
other RF: age, HTN, smoking, black race
Charcot Bouchard microaneurysm
assoc. with chronic HTN.
affect small vessels (basal ganglia, thalamus).
epidural hematoma
rupture of middle meningeal a.
often second to temporal bone fx.
LUCID interval.
rapid expansion under systemic arterial pressure = transtentorial herniation and CN III palsy.
CT: biconvex disk (lens), NOT crossing suture lines. can cross falx, tentorium.
subdural hematoma
rupture of bridging veins.
SLOW venous bleeding.
seen in elderly, alcoholics, blunt trauma, shaken baby.
CT: crescent shape, crosses suture lines. midline shift. preserved gyro. cannot cross falx, tentorium.
subarachnoid hemorrhage
rupture of berry aneurysm or AVM.
rapid and severe onset.
worse HA of my life.
spinal tap bloody or yellow (xanthochromic).
CT: 2-3 days later, risk of VASOSPASM due to blood breakdown (not seen but treat with NIMODIPINE) and rebleed (seen on CT).
intraparenchymal (hypertensive) hemorrhage
most commonly due to systemic HTN.
also due to amyloid antipathy, vasculitis, neoplasm.
occurs in basal ganglia and internal capsule but can be lobar.
most vulnerable to ischemic damage
hippocampus
neocortex
cerebellum
watershed areas
irreversible neuron injury (due to ischemia > 5 min)
12-48 h: red neurons 24-72 h: necrosis, neutrophils 3-5 d: macrophages 1-2 w: reactive gliosis, vasc prolif > 2 w: glial scar
ischemic brain disease: atherosclerosis
thrombi lead to ischemic stroke with subsequent necrosis. form cystic cavity with reactive gliosis.
ischemic brain disease: ischemic stroke
emboli block large vessels.
caused by Afib, carotid dissection, patent foramen ovale, endocarditis.
tx: tPA within 4.5 hrs IFF pt presents w/in 3 hrs of onset and has no major risk for hemorrhage
ischemic brain disease: ischemic stroke (LACUNAR)
block small vessels.
often second to HTN.
ischemic brain disease: hemorrhagic stroke
intracerebral bleeding.
caused by HTN, anticoag, cancer (abn vessels) or reperfusion after ischemic stroke (fragile vessels)
ischemic brain disease: TIA
brief reversible episode of neuro dysfunction lasting < 24 hrs.
due to FOCAL ischemia.
stroke imaging
diffusion weighted MRI: bright in 3-30 min for 10 days.
noncontrast CT: dark in 24 hrs.
bright indicates hemorrhage; DO NOT USE tPA.
normal pressure hydrocephalus
wet wobbly wacky = incontinence, ataxia, dementia.
increase subarachnoid space volume but NO INCREASE in CSF pressure.
reversible.