8. Ventricle CSF and Hydrocephalus

Question 1

At one time, there are about 125-150mL of CSF in the body, constantly renewed. Where can most of the CSF be found?

Answer 1

65% is found in the lateral ventricle

Question 2

Choroid plexus produces the CSF which is a specialized layer of ependymal cells which makes what?

Answer 2

choroidal epithelium overlying highly vascularized villi

Question 3

In the BBB, there are continuous tight junctions between the ENDOTHELIAL cells, a basement membrane, astrocytic foot processes. What is different in CSF blood barrier? 3

Answer 3

separating the CSF from blood
more permable than BBB
tight junctions are located between CHOROID cells

Question 4

Normal CSF is clear and colorless with few cells and low protein, offering quantitative differences from plasma. What is the most important difference between CSF and plasma?

Answer 4

protein in plasma is 7000 will it is 20 in CSF

increase or decrease in proteins in CSF = pathology

Question 5

What are the four main functions of CSF?

Answer 5

protection: shock absorber
buoyancy
Metabolic - takes drugs away from brain
Endocrine medium: hormone transport

Question 6

What are the four cavities within the brain?

Answer 6

lateral ventricle
3rd ventricle
cerebral aqueduct
4th ventricle
(continuous with with central canal in SC)

Question 7

How does the CSF leave the fourth ventricle? (2)

Answer 7

2 lateral foramina of luschka

1 medial foramen of magendie

Question 8

What is the entire pathway for CSF flow? (9)

Answer 8

CSF is made from choroid plexus from blood-csf barrier

1. Lateral ventricle
2. interventricular foramen of monroe
3. third ventricle
4. cerebral aqueduct
5. fourth ventricle
6. lateral and median apertures (lateral foramina of luschka/ medial foramen of magendie)
7. Subarachnoid space
8. Arachnoid Villi of dural venous sinuses
9. Venous blood

Question 9

What is the difference between arachnoid villi and granulations?

Answer 9

granulations are older while villi are new

Question 10

What is expansion of the ventricular system due to increase volume of CSF contained within them?

Answer 10

hydrocephalus

Question 11

The causes of hydrocephalus can be due to overproduction, under absorption at villi, or obstruction of outflow from ventricles. What are they two types?

Answer 11

communicating/ non-obstructive

non-communicating/ obstructive hydrocephalus

Question 12

What type of hydrocephalus is due to a blockage after the ventricles due to abnormalities of arachnoid villi, associated with increased ICP?

Answer 12

communicating/nonobstructive hydrocephalus

Question 13

What hydrocephalus is characterized by enlarged lateral and 3rd ventricles and increased CSF pressure?

Answer 13

Normal Pressure Hydrocephalus

Question 14

What are the traid of symptoms associated with normal pressure hydrocephalus?

Answer 14

dementia
apraxic gait
urinary incontinence

Question 15

What is a compensatory enlargement of cerebral ventricles and subarachnoid spaces, typically with no increase in CSF pressure?

Answer 15

Hydrocephalus Ex-Vacuo

Question 16

What are the 3 common causes of hydrocephalus Ex-Vacuo?

Answer 16

brain atrophy
post-traumatic brain injuries
Psych disorders like schizophrenia

Question 17

What is caused by CSF flow obstruction that occurs within the ventricular system, with the enlargement being located proximal to the obstruction?

Answer 17

obstructive hydrocephalus

Question 18

What is narrowing of the cerebral aqueduct blocking the flow of CSF (MOST COMMON SITE), caused by tumors, narrow aqueduct, and gliosis?

Answer 18

Aqueductal stenosis

Question 19

What are the most common signs and symptoms of aqueductal stenosis? 6

Answer 19

thunderclap headache (severe/sudden onset)
papilledema
enlarged head
cognitive delays
decreased consciousness
cant look upwards

Question 20

What is the disease associated with a large posterior fossa cyst continuous with the fourth ventricle, involving hypoplasia of cerebellum and agenesis of cerebellar vermis?

Answer 20

dandy-walker malformation

Question 21

What is caused by herniation of the cerebellar tonsils and medulla through the foramen magnum, usually accompanied with myelomeningocele and hydrocephalus?

Answer 21

Chiari II Malformation

Question 22

What develops later in life and occurs when something happens to prevent CSF in the brain from draining properly? (5)

Answer 22

Acquired Hydrocephalus
Tumor
Block CSF flow
Bleeding (subarachnoid hemorrhage)
Head trauma
Infection/meningitis