neuro cortex - neurovascular

Question 1

where does the anterior circulation originate from?

Answer 1

the paired internal carotid arteries

Question 2

where does the posterior circulation arteries originate ?

Answer 2

paired vertebral arteries which then join together to form the basilar artery

Question 3

what do the anterior and posterior circulations join to form?

Answer 3

the circle of willis

Question 4

what is the origin and path of the ICA?

Answer 4

• originates from the common carotid arteries at the carotid bifurcation (C4)
• then enters base of skull through carotid canal then transverses the foramen lacerum

Question 5

what are the branches of the ICA?

Answer 5

opthalamic, anterior choroidal, posterior communicating arterie, middle cerebral artery and anterior cerebral artery

Question 6

what is the origin and path of the anterior cerebral artery?

Answer 6

• originates from the termination of the ICA
• arches over the corpus callosum in the longitudinal fissure
• the right and left anterior cerebral arteries are connected together via the anterior communicating artery

Question 7

what is the function of the anterior cerebral artery?

Answer 7

• supplied the medial part of the cerebral hemispheres back to the parietal lobe
• supplies most of the corpus callosum, the anterior limb of the internal capsule and part of the caudate nucleus

Question 8

what is the origin and patch of the middle cerebral artery?

Answer 8

• originates from the termination of the ICA and is larger than the anterior cerebral
• path extends form the ICA to the sylvian fissure, it the exits the sylvian fissure onto the lateral surface of the hemisphere

Question 9

what is the function of the middle cerebral artery?

Answer 9

supplies the majority of the lateral hemisphere, basal ganglia and internal capsule

Question 10

what is the origin of the vertebral artery?

Answer 10

• arises from the subclavian artery and extends through the transverse foramen of the cervical vertebrae (C6-C1)
• the left and right vertebral arteries join togehter to form the basilar artery

Question 11

what are the main branches of the vertebral artery?

Answer 11

posterior inferior cerebellar arteries (which supply the posterorinferior cerebellar hemispheres)

Question 12

what is the origin and path of the basilar artery?

Answer 12

• from the combination of the vertebral arteries at the base of the pons then courses superiorly towards the midbrain - it then terminates at the interpeducular cistern by giving off 2 posterior cerebral ateries

Question 13

what are the 3 main branches of the basilar artery?

Answer 13

• anterior inferior cerebellar artery - supplies the anterolateral part of the cerebellum and gives off the labyrinthine artery (supplies the inner ear)
• numurous pontine branches
• superior cerebellar artery (supplies the superior aspect of the cerebellum)

Question 14

what is the origin and path of the posterior cerebral artery?

Answer 14

• originates from the termination of the basilar artery

- courses backwards towards the occipital lobe

Question 15

what is the function of the posterior cerebral artery?

Answer 15

connects the anterior and posterior circulations

Question 16

what are the dural venous sinuses?

Answer 16

large venous channels that are contained within the dura

- contain arachnoid granulations, which allow CSF to be absorbed from the subarachnoid space back to the venous system

Question 17

what is the superior saggital sinus?

Answer 17

a large unpaired venous sinus that runs from the anterior aspect of the falx cerebri and terminates at the confluence of sinuses, where it is joined by the straight sinus
- from there, blood drains into the left and right transverse sinuses to drain into the internal jugular vein

Question 18

what do cerebral veins do?

Answer 18

drain blood into the sinuses

the superficial veins drain into the super saggital sinus while the deep veins mainly drain into the straight sinus

Question 19

how to diagnose SAH?

Answer 19

CT scan

LP - xantthochromia (yellow CSF)

Question 20

what is a cavernous malformation?

Answer 20

well circumscribed benign vascular lesions encompassing sinusoidal spaces lined by endothelium and separated by elastin, with a rim of hemosiderin-laden macrophages surrounding it

Question 21

how to investigate cavernous malformation?

Answer 21

CT - useful in acute haemorrhage

MRI - (gradient-echo, T2, of weighted imaging) - popcorn like apperance

Question 22

what are the symptoms of a PCOM (posterior communicating artery) aneurysm?

Answer 22

compression of CN III causing 3rd nerve palsy (dilated pupil which is unreactive to light and if not treated, with progress to complete 3rd nerve palsy with ptosis and extraocular muscle palsy)

Question 23

what are the symptoms of an unruptures anterior communicating artery?

Answer 23

compression of the optic chaism

Question 24

what are the symptoms of an unruptured basilar artery?

Answer 24

headache, third nerve palsy, confusion, hemiparesis, meningism, drowsiness, diplopoa, nausea and vomiting

Question 25

which scoring should be used in assessing a TIA?

Answer 25

ABCD2 age, BP, clinical features, duration (mins), diabetes >4 = referral within 24 hours <4 = seem within 7 days