Stroke, Aneyrysm Flashcards
R and L Vertebral arteries join together to form the [ ] artery
basilar
circle of willis
A structure at the base of the brain that is formed by the joining of the carotid and basilar arteries.
Anterior cerebral artery supplies what two cortexes?
Primary motor cortex
primary somatosensory cortexe (hips to head)
Middle cerebral artery supplies what three cortexes?
frontal primary motor cortex (hips to head)
primary somatosensory cortex (hips to head ) in parietal lobe
auditory cortex (temporal lobe)
Posterior cerebral artery supplies what four cortexe?
Visual cortex
hippocampus (long-term memory_
Thalamus
hypothalamus
Homunculus and stroke deficit distribution
motor and somatosensory allocations on cerebral cortex
based on vascular compromise in stroke, certain areas will be affected, leading to specific deficits in sensory, motor, or both
Which of the following happens to cerebral circulation and aging:
a. low energy metabolism
b. lower perfusion
c. build up of neurovascular coupling
d. diaschisis
e. breakdown of cerebrovascular reactivity
f. high perfusion due to arrhythmia, heart failure, cardiac arrest
g. build up of cerebrovascular autoregulation
A, b, d, e
c: breakdown of coupling
f: low perfusion
G: breakdown of autoregulation
Diaschisis
decreased activity of surviving neurons after damage to other neurons
seen in aging brain
could be a distant area of brain that is damaged, yet since it’s still connected, there are deficits in other distant connected areas
Which is the more common form of stroke: ischemic or hemorrhagic?
ischemia
Ischemic stroke
Blocked blood flow to the brain
diminished flow–> ischemia/anoxia to brain–> brain tissue death–> cerebral infarction
Can be due to:
- atherosclerotic plaquing
- blockages from thromboembolisms
- arterieal structure changes (e.g. stripping of tunica media resulting in arterial dissection)
Large-vessel thrombosis occurs with the blockage of larger arteries like:
carotid or middle cerebral artery
Lacunar stroke
Small-vessel thrombosis occuring in small, deep penetrating arteries of the brain.
Arteriovenous malformations (AVM)
abnormal connections between arterial and venous systems
blood flows too quickly from arteries, pushing on walls of veins, and walls thus begin to weaken/narrow and bulge
AVMs are often precursors of what two phenomena?
- aneurysm
2. hemorrhagic stroke (intracranial bleeding)
AVM that hasn’t burst
usually no signs/symptoms
but may cause headaches
AVM that has burst
hemorrhagic stroke
Aneurysm: what is it and how it develops?
out-pocketing of the arterial wall (like a hernia)
normally develops in an area of an artery where there’s abnormal loss/absence of the muscular layer of the artery wall–>leading to 2 layers, rather than the normal 3 layers
Where are aneurysms most common in the brain?
most often occur in circle of willis–specifically related to middle cerebral artery
signs and symptoms of aneurysm
can be innocuous (no s/s) or can cause symptoms if close to a sensitive structure (e.g. a cranial nerve)
MC s/s
- headaches
- eye pain
- vision deficits
- oculomotor deficits
subarachnoid hemorrhage
Ruptured cerebral aneurysm
“worst headache of my life”
- stiff neck (blood + meningeal irritation)
- nausea, vomiting
- changes in mental status (drowsiness)
- eye pain, photophobia, dilated pupils
- LOC
- hypertension
- motor deficits
- back/leg pain
- CN defcitis
Case: patient comes in complaining of “worst headache of their life”. Headache, nausea and vomiting. You take vitals and heart rate and respiratory rate are both decreased. What is the most likely dx? Management?
subarachnoid hemorrhage
a cerebral aneurysm has ruptured, get them to ER asap