Ventricular and Vascular System Stephens Test #2

Question 1

Which ventricles are frequently enlarged in hydrocephalus?

Answer 1

Lateral

Question 2

What foramen would a choroid plexus ependymoma obstruct?

Answer 2

Interventricular foramen of Monroe, which connects the lateral ventricles to the third

Question 3

What would a midbrain tumor such as an astrocytoma disrupt?

Answer 3

CSF flow from third ventricle through the cerebral aquaduct into the fourth ventricle resulting in hypertrophied lateral ventricles

Question 4

What is Syringomyelia?

Answer 4

The central canal enlarges and develops its own cavity called syrinx. It causes patients to have bilateral anesthesia of shoulders and upper limbs

Question 5

Where are choroid plexuses located and what is the significance?

Answer 5

Located on floors of lateral and roof of third and fourth ventricles. They produce CSF

Question 6

Describe the composition of CSF.

Answer 6

similar to blood ultrafiltrate with higher concentrations of sodium, chloride, and magnesium. Lower concentrations of potassium and calcium and glucose and protein

Question 7

Presence of greater than ___ RBC’s or lymphocytes is abnormal?

Answer 7

six

Question 8

What is normal CSF pressure and amounts?

Answer 8

100-200 mm of water and 20-25 ml in ventricles and 140 ml in the system

Question 9

How does transient hydrocephalus occur with SAH?

Answer 9

The arachnoid villi can become temporarily blocked with a sub arachnoid hemorrhage and cause increase in pressurer

Question 10

Describe flow of CSF

Answer 10

From ventricular system to subarachnoid space to the venous system via venous lacunae

Question 11

How does hydrocephaly differ in infants/young children vs adults?

Answer 11

Infants and young children have fontanelles or unfused sutures while adults have fused sutures. The fused sutures do not allow for the head to expand therefore pressure builds intracranially. With infants and young children their heads expand due to the lack of fusion of the sutures.

Question 12

What is external hydrocephalus?

Answer 12

Excessive accumulation of CSF in subarachnoid space with enlargement of that space by compression of CNS. can be supratentorial, infratentorial or both

Question 13

What is supratentorial external hydrocephalus?

Answer 13

most commonly associated with senile atrophy of the cortex as seen with alzheimers

Question 14

What is infratentorial external hydrocephalus?

Answer 14

seen in combo with communicating hydrocephalus

Question 15

What is internal/noncommunicating hydrocephalus?

Answer 15

CSF doesn’t drain into subarachnoid space due to obstruction of intraventricular foramen, cerebral aqueduct, and medial and lateral foramina. Results in dilation of ventricles proximal to obstruction with.

Question 16

What is communicating hydrocephalus?

Answer 16

Combo of infratentorial external and internal hydrocephalus. Due to adhesions and fibrosis in the subarachnoid spaces, cerebral edema or uncal herniation the space btw tentorial notch and midbrain can be obstructed. CSF can freely move through ventricular system, but cannot circulate over cerebrum to be reabsorbed at arachnoid villi next to and in the superior sagittal sinus

Question 17

What supplies most of the blood to the brain?

Answer 17

ICA and then vertebral

Question 18

How long does it take for a person to become unconscious if blood flow is interupted?

Answer 18

5-20 seconds

Question 19

What happens if blood flow is interrupted for 4-8 minutes?

Answer 19

irreversible brain damage

Question 20

Regional or focal ischemia is seen in ____ when theres an occlusion of a large nutrient artery

Answer 20

athero-cerebral infarction (stroke)

Question 21

What is focal ischemia?

Answer 21

neuronal injury or necrosis to central core territory of arterial supply and varying degrees of dysfunction to potential viable tissue in surrounding marginal territory (ischemic penumbra)

Question 22

What areas of the brain are damaged in an ischemic injury? (Dr. Stephens highlighted and underlined “remember” this fact)

Answer 22

Distal branches of cerebral arteries and particular neuronal populations such as pyramidial cells of hippocampus, especially CA1 or Sommer’s sector are damaged.

Question 23

Which type of stroke is more common hemorrhagic or ischemic?

Answer 23

Ischemic 85%

Question 24

Which two arteries pierce the dura mater and course in the subarachnoid space?

Answer 24

ICA and vertebral

Question 25

Where is the BBB absent?

Answer 25

Pineal body area postrema and median eminence of hypothalamus

Question 26

What are the branches of the ICA?

Answer 26

Opthalmic PCoA AChA

Question 27

Describe the PCoA.

Answer 27

Located btw ICA and posterior cerebral arteries. Its ganglionic or penetrating branches suppply internal capsule and the basal ganglia

Question 28

What does the cisternal segment of the anterior choroidal artery supply?

Answer 28

internal capsule, lateral geniculate nucleus, lateral cerebral peduncle, globus pallidus, caudate nucleus, uncus

Question 29

What does the intraventricular segment of the anterior choroidal artery supply?

Answer 29

Anterior portion of the choroid plexus

Question 30

What causes a complete anterior choroidal stroke?

Answer 30

Due to cardioembolic sources and carotid stenosis.

Question 31

What causes small strokes of the AChA?

Answer 31

T2 DM Htn and hyperlipidemia

Question 32

What does an infarction to the AChA territory result in?

Answer 32

AChA syndrome with triad of hemiplegia hemianesthesia and contralateral hemianopia.

Question 33

The ACA is a terminal branch of the ____. What circulation does it provide?

Answer 33

ICA. This artery has the highest incidence of cerebral aneurysms and provides important collateral circulation btw anterior and posterior circulations

Question 34

Approximately 25% of cerebral aneurysms occur in this artery. This artery connects the two anterior cerebral arteries and it can be absent. What is it?

Answer 34

Anterior communicating artery ACoA

Question 35

This artery supplies the anterior 2/3 of the medial side and supero-lateral portion of the hemisphere. Occlusions of this artery can result in contralateral paresis or paraesthesia of leg and foot. What is it?

Answer 35

Cortical branches of the ACA

Question 36

In the ACA, what happens when A2 is occluded?

Answer 36

Occlusion of this segment or distal to it can cause deficits with the affected cortical area ACA syndrome

Question 37

What happens in the ACA with an occlusion to the A1 segment?

Answer 37

doesn’t produce symptoms bc of the collateral circulation

Question 38

Where does MCA come from, what % of aneurysms occur there, what are its branches and what do they supply? Which artery from the lateral striate artery branch is prone to rupture?

Answer 38

• ICA
• 25%
• Penetrating branches called the medial and lateral striate or the thalamostriate arteries also Cortical branches
• supply parts of the internal capsule corpus striatum and thalamus
• Artery of cerebral hemorrhange

Question 39

Describe the cortical branches from the MCA,

Answer 39

• Central artery and Frontal branches come from the cortical branches
• Central artery is in the central sulcus and supplies primary amotor and somesthetic cortices
• Frontal branches supply premotor and prefrontal cortices and brocas area

Question 40

What would result if thrombosis of the central artery occured?

Answer 40

Contralateral spastic paralysis &/or paraesthesia of face and upper half of the body

Question 41

What results from thrombosis of the frontal branches of the Cortical artery from the MCA?

Answer 41

The frontal branches supply brocas area as well as premotor and prefrontal cortices. Therefore a thrombosis would result in expressive or Broca’s aphasia where patients cannot initiate speech motor patterns.

Question 42

What are the four segments to the MCA?

Answer 42

• M1: sphenoidal or horizontal segment originating at the bifurcation of the ICA
• M2: Insular segment terminates at circular sulcus of insula and makes a right angle turn
• M3: Opercular segment
• M4: Cortical segment originates at the surface of sylvian fissure and terminates at cortical territory

Question 43

What happens if there is obstruction of the angular artery?

Answer 43

• Wernicke’s aphasia, patients are talkative but it doesn’t make sense, they lack content and meaning in their spokekn and written comprehension of language
• Angular artery supplies supramarginal and angular regions

Question 44

What is central cord syndrome?

Answer 44

Disruption of blood flow to anterior spinal artery so ischemia to the central region. Thrombosis to the anterior spinal artery causes this syndrome.

• Characterized by central necrosis and cavitation of the spinal cord and development of syrinx

Question 46

Which artery could be compromised secondary to thoracolumbar fracture or surgical repair of abdominal aorta?

Answer 46

Great anterior artery of Adamkiewicz

Question 47

Thrombosis of the PICA results in?

Answer 47

Lateral Medullary (wallenbergs) Syndrome

Question 48

What are the four segments of the PCA?

Answer 48

• P1: Pre communicating segment
• P2: post communicating segment
• P3: Quadrigeminal segment
• P4: Cortical segments