Blood vessels and pathology Flashcards
What are the two major blood vessels that supply the brain?
Internal carotids and vertebral arteries
What is an AV malformation?
It is an irregular connection between arteries and veins with NO capillary bed in between
What is an aneurysm?
Site(s) of weakening in the arterial wall, often near points of bifrucation of arteries (in the circle of willis)
What are the 3 types of aneurysms?
fusiform
saccular (Berry aneurysms)
Irregularly shaped
Where in the circle of Willis is the most common site of aneurysm?
anterior communicating artery
What is/are common symptoms of an aneurysm in the anterior communicating artery?
Compression of the optic chiasm causing visual defects
What is/are common symptoms of an aneurysm in the posterior cerebral artery?
Compression of CN III causing ptosis, lateral deviation of the eye, and the dilated pupil
What is a hemorrhagic stroke?
Hemorrhagic stroke occurs when an aneurysm bursts and blood leaks out and comes in contact with surroudning tissue. This blood causes swelling and pressure and damages the surrounding cells
What is an ischemic stroke?
Ischemic stroke is caused when insufficient blood is delivered to the brain
What are watershed zones? What are watershed infarcts? What are the two watershed areas in the brain?
Watershed zones are regions that recieve blood supply from distal ends of two arterial systems
In the setting of low blood pressure, blood can’t reach these areas resulting in infarction of the watershed zone
ACA-MCA watershed and the MCA-PCA watershed
What areteries supply the precentral and postcentral gyri? What portions?
The ACA feed the trunk and lower extremities
The MCA feeds the arms and upper extremities
What are the lenticulostriate arteries and what artery do they branch from?
They feed the basal ganglia and the internal capsule
They branch from the MCA
What is the anterior choroidal artery? Where does it branch from?
Anterior choroidal artery supplies the choroid plexus in the lateral ventricles
It branches from the middle cerebral artery
What blood vessel supplies the majority of the dura? What artery does it branch from? What foramen in the skull does it pass through?
middle meningeal artery
branches from the maxillary artery (from the external carotid artery)
foramen spinosum
The ______, located laterally on the skull, contains the frontal, parietal, sphenoid, and temporal bones. Trauma to this area can tear the middle meningeal artery
Pterion
If the middle meningeal artery is torn (caused by trauma to the pterion), what type of hematoma is formed? What sign is seen on imaging?
epidural hematoma
Lens-shaped
What does the anterior cerebral artery supply? What deficits can be seen in ACA occlusion?
(blood supply is indicated in picture)
contralateral limb weakness and sensory loss, frontal lobe dysfunction (flat affect, apraxia[inability to perform purposeful function], abulia[absence of will power], and incontinence
What is alien hand syndrome?
involuntary movements of the contralateral hand and arm in a ACA stroke
What can an occlusion to the middle cerebral artery cause? If the MCA stroke occurs in the patient’s dominant hemisphere, what can occur?
contralateral hand and face weakness and upper quadrent visual field loss (visual pathway moves through parietal and temporal lobes towards occipital lobe)
Dominant hemisphere is usually left; aphasia (Broca and Wernicke)
What happens when the lenticulostriate arteries are occluded?
devastating contralateral body weakness (supply the basal ganglia - only motor)
What happens if the basilar artery is occluded?
Damage to the long tracts in the pons leading to “locked-in syndrome” (quadriplegia and inability to move the facial muscles; awareness, mentation, and sensation are intact)
What happens if the pontine arteries are occluded?
contralateral weakness
What happens if the labyrinthe arteries are occluded
ipsilateral hearing loss
What happens if the posterior cerebral artery is occluded?
contralateral visual field defects
