2 Blood Supply and Ventricular Supply - B Flashcards
what is a cause of median and lateral aperature obstructions
arnold-chiari malformation or dandy-walker cyst (CSF buildup in the lateral, 3rd, and 4th ventricles)
occlusion in the temporal branches of the middle cerebral a cause
inability to localize sounds
what do the branches of the parieto-occipital a supply
visual association cortex
the middle cerebral a (internal carotid branch) suppplies
medial and lateral striate/thalamostriate
- internal capsule
- corpus striatum
- thalamus
occlusion in the angular artery of the middle cerebral a causes
wernicke’s aphasia
- fluent in speech but can’t understand spoken and written comprehension
- circumlocute with inappropriate word choices and new word creations
- receptive language disorder
occlusions in the frontal branches of the middle cerebral a can cause
broca’s aphagia - understanding speech but unable to recipricolly communicate
labyrinthinitis is
- atherosclerosis or inflammation of the labyrinthine a resulting in irritation of hte vestibulocochlear apparatus
- disturbs equilibrium and or hearing
what is the progression of an epidural hematoma
- traumatic event
- unconcious but rapid recovery
- hematoma presses on cerebral hemisphere
- causes uncal herniation
the pontine aa are branches off of
basilar a
what is frequently a cause of vasular insufficiency to globus pallidus and hippocampus in eldery
anterior choroidal a
what is a cause of obstruction of the cerebral aqueduct
midbrain astrocytoma (build up in the lateral and 3rd ventricles)
where does the internal cerebral v go
- runs next to the parahippocampal gyrus
- receives thalamostriate and anterior septal vv
- drains into the great v of galen and then to the straight sinus
how do you treat an epidural hematoma
evacuate the hematoma
where is the 3rd ventricle
between thalami
where does the great vein of galen go
- runs next to the posterior portion of the corpus callosum
- receives the internal cerebral v and basal v of rosenthal
- drains into straight sinus
what are the clinical signs of hydrocephalus in adults
increased intracranial pressure
papillaedema
abducens palsy (eye facing medially - lost lateral rectus m)
what is responsible for draining blood from the spinal cord
baston’s plexus
- located in the epidural space
- empties into intervertebral vv and then segmental vv
what does the anterior spinal a supply
most of the central gray matter of the cord and the anteromedial portion of white matter
what occurs with thrombosis of superior sagittal sinus or right transverse sinus
cortical ischemia and or necrosis
the cerebral aa run in subarachnoid space and their branches penetrate into brain parenchyma and are surrounded by what
virchow robin space and pia mater
what do the temporal branches of the posterior cerebellar a supply
inferior temporal cortex
what type of hydrocephalus is most commonly associated with senile atrophy of the cortex (alzheimers)
supratentorial external hydrocephalus
the posterior circulation of the brain is handled by
vertebral a
- anterior spinal a
- posterior spinal aa
- posterior inferior cerebellar a
basilar a
- anterior inferior cerebellar a
- labyrinthine a
- superior cerebellar a
- posterior cerebal a
what connects the 3rd and 4th ventricles
cerebral aqueduct
what is internal hydrocephalus
noncommunicating type where CSF cannot drain into the subarachnoid space
-results in dilation of ventricles proximal to obstruction
why do we find erythrocytes in CSF
subarachnoid hemorrhage
what occurs with occlusion of the great v of galen
usually fatal since it drains deep brain
occlusion of the posterior inferior cerebellar a causees
lateral medullary syndrome/wallenberg syndrome
what is a cause of interventricular foramen obstruction
3rd ventricle choroid plexus ependymoma (backs up into lateral ventricle)
how is a subdural hematoma different from a epidural hermatoma
more insidious onset
-can have lethary, seizures, or headaches
what causes communicating hydrocephalus
obstruction of the narrow space between the tentorial notch and midbrain
-caused by adhesions in subarachnoid space secondary to:
– previous inflammation (infantile meningitis)
–cerebral edema
–uncal herniation
what do the penetrating branches of the posterior cerebral a supply
- internal capsule
- thalamus
- choroid plexus of the lateral ventricle
- upper midbrain
where is the BBB absent
- pineal body
- area postrema
- median eminence of the hypothalamus
which AA supply the brain and where do they run
internal carotid and vertebral aa; subarachnoid space and then give off cerebral aa
the 2 posterior spinal a branch off of what
vertebral or pica
what is hydrocephalus
increase in cerebral mass/size due to CSF
present in:
- ventricular space
- subarachnoid space
- or both
what does the anterior choroidal a supply
- choroid plexus of lateral ventricle
- internal capsule
- basal ganglia
- thalamus
- rostral midbrain
the posterior inferior cerebellar a supplies
- posterior inferior portion of cerebellum
- posterolateral aspect of the medulla
- choroid plexus of the fourth ventricle
what is the difference b/n and epidural hematoma and subdural hematoma
epidural is arterial blood; subdural is venous
what is communicating hydrocephalus
combination of infratentorial external hydrocephalus and internal hydrocephalus
the anterior inferior cerebellar a is located
in the pontobulbar sulcus
what are the symptoms of central cord syndrome
–central necrosis and cavitation of the spinal cord
-sensory and motor deficits to UE>LE and distal musculature> proximal
what is the major supply to the inferior 2/3 of the spinal cord
great anterior artery of adamkiewicz
what does the posterior pericallosal a (of the posterior cerebral a) supply
anastomoses with anterior pericallosal a of the anterior cerebral a
what happens when the great anterior artery of adamkiewicz is compromised
ischemic necrosis of spinal chord (partial or complete transection)
what allows CSF to go from teh 4th ventricle to the subarachnoid space of the spinal cord
foramen of magendie
what does the great anterior artery of adamkiewicz arise from
left inferior intercostal or superior lumbar aa and contributes to the anterior spinal a
how do the pontine aa branch to their locations
pie-wedge like
-this is seen also with the necrosis they cause
in communicating hydrocephalus, CSF cannot move over brain and be absorbed at arachnoid villi to go into the superior saggital sinus, what does this cause
- hypertropy of ventricles (internal hydrocephalus)
- accumulation of CSF in infratentorial space (external hydrocephalus)
what occurs with thrombosis of straight sagittal sinus or left transverse sinus
-ischemia and/or necrosis of deep brain (usually fatal)
the anterior cerebral a supplies what
runs next to the olfactory and optic nn and supplies:
- anterior 2/3 of the medial side and supero-lateral portion of the hemisphere
- paracentral lobule region (sensation and motor to LE)
where are athe lateral ventricles
between each cerebral hemisphere
epidural hematoma is d/t
fracture of the pterion that ruptures the meningeal a
-runs b/n dura mater and skull
occlusion of the anterior cerebral a affects what
paracentral lobule region and causes contralateral paresis and/or paraesthesia of leg and foot
the posterior cerebral a has what branches
- penetrating branches
- temporal branches
- perieto-occipital a
- calcarine a
- posterior pericallosal a
the uncus is a part of what lobe
temporal
what occurs with a great vein of galen varice
may compress pineal body and posterior commissure
where does the basal v of rosenthal go
- runs next to the cerebral peduncle
- receives middle deep cerebral and anterior cerebral vv
- drains into the great v of galen and then to straight sinuses
what does the calcarine a of the posterior cerebral a supply
primary visual cortex
uncal herniation is when
uncus hernaites through tentorial notch (opening in tentorium cerebelli)
occlusions in the parietal branches of the middle cerebral a cause
interpretive disorders and body neglect
what are some symptoms of uncal herniation
unilateral dilating pupil
-CN 3 compression (down and out)
late sx
- contralateral hemiparesis and respiratory compromise
- kernohans notch
the superior cerebellar a supplies
- superior lateral portion of cerebellum
- deep cerebellar nuclei
- part of pons and midbrain
what are the branches of the middle cerebral a
central a - primary motor and somesthetic cortices
frontal brs - premotor and prefrontal cortices as well as broca’s area in dominant hemisphere
parietal brs - association cortex
temporal brs - primary auditory cortex
angular a - supramarginal and angular regions as well as wenicke’s area in dominant hemisphere
what is tonsilar herniation
acute and rapidly fatal
- cerebellar tonsils herniate through foramen magnum
- compresses medulla and leads to respiratory arrest
the anterior inferior cerebellar a supplies
- anterior inferior portion of cerebellum
- superior and middle cerebellar peduncles
- part of brainstem
the anterior cerebral a has what branches
- recurrent a of heubner
- anterior communicating a
- cortical branches
—anterior pericallosal a
—callosomarginal a
why is the anterior choroidal a prone to thrombosis
long course in subarachnoid space
spinal cord trauma may interrupt blood to spinal cord especially if supplied by 2 arterial supplies such as
at C2-3, T1-4, and L1 (at the enlargements)
where are the obstruction sites of internal hydrocephalus
interventricular foramen
cerebral aqueduct
medial and lateral aperatures
the blood brain barrier is made of what structures
- endothelial cell layer
- basement membrane
- pericyte
- foot processes of astrocytes and oligodendrocytes
what are the clinical signs of hydrocephalus in infants and young children
increased intracranial pressure which can enlarge sutures
papilledema
what connects the lateral and 3rd ventricle
foramen of monro
what can compromise the great anterior artery of adamkiewicz
thoracolumbar fracture or surgical repair of AAA
the posterior inferior cerebellar a is a branch of
the vertebral a
the labyrinthine a is a branch of
basilar a or off AICA (anterior inferior cerebellar a)
what are the symptoms of a falx herniation
- headache
- contralateral leg weakness
- sometimes no clinical symptoms
which plexus forms the majority of the csf
lateral and 4th ventricle
the pontine aa supply
medial and lateral aspects of the pons
what happens with a falx herniation
cingulate gyrus can herniate
what is external hydrocephalus
communicating hydrocephalus (too much CSF in the subarachnoid space)
-the ventricles are normal sized
what symptoms can occur as a result of a posterior cerebral a occlusion
ischemic necrosis of the primary visual cortex
-causes contralateral homonymous hemianopsia with macular sparing
where is the 4th ventricle
between the cerebellum and pons
what is kernohans notch
uncal herniation causes pressure on the ipsilateral brain stem
- contralateral limb weakness
- increased pressure pushes brainstem into tenotorium cerebelli
the superior cerebellar a is located posterior to
CN 3
where does the straight sagittal sinus normally drain to
left transverse sinus
what is the main a of the internal ear
labyrinthine a
the posterior spinal aa supply
- dorsal roots and about 75% of the posterior columns
- along with radicular aa they supply peripheral margins of the cord
what causes central cord syndrome
disruption of blood flow to the anterior spinal a
- caused by:
- thrombosis or hyperextension of the neck
- ischemia of the central region of the cord
where does the superior sagittal sinus typically drain to
right transverse sinus
what aa make up the circle of willis
what makes up the anterior circulation of the brain
internal carotid and branches
- opthalamic a
- anterior choroidal a
- anterior cerebral a
- middle cerebral a
what is associated with children and elderly for subdural hematomas
- children - skull fracture
- elderly - fragile blood vessels
what makes CSF
ependymal cells of the choroid plexuses
where do we pull CSF
L4-5
what can cause posterior cerebral a occlusion
thrombosis and uncal herniation
what is the anterior inferior cerebellar a close to
CN 6, 7, 8, and the flocculus of the cerebellum
