Ventricle, CSF, & Hydrocephalus

Question 1

This is the fluid around the brain and spinal cord that helps provide homeostasis and mechanical protection and buoyancy.

Answer 1

Cerebrospinal Fluid (CSF)

Question 2

The CSF also helps remove brain __________ and contains an endocrine mechanism by helping with ________ transport.

Answer 2

Metabolites

Hormone

Question 3

CSF is produced primarily by the ________ _______ (by ependymal cells) which is found in the lateral ventricle (65 percent produced here), third ventricle, and fourth ventricle.

Answer 3

Choroid Plexus

Question 4

The Choroid Plexus consists of villous folds lined by epithelium with a central core of highly vascularized connective tissue. The specialized layer of _________ cells is the choroidal epithelium that overlies these villi.

Answer 4

Ependymal

Question 5

Normal CSF is clear and colorless and has few cells and low ________.

Answer 5

Protein

Question 6

CSF does not differ from ________ qualitatively, but does differ quantitatively.

Answer 6

Plasma

Question 7

How do we test for CSF composition?

Answer 7

By lumbar puncture between L4 and L5

Question 8

What drains the lateral ventricles into the 3rd ventricle?

Answer 8

Interventricular Foramina of Monro (right and left)

Question 9

What drains the 3rd ventricle into the 4th ventricle?

Answer 9

Cerebral Aqueduct (of Sylvius)

Question 10

What drains the 4th ventricle into the Subarachnoid Space?

Answer 10

Foramina of Luschka (Lateral Aperture)

Foramina of Magendie (Medial Aperture)

Question 11

CSF made by choroid plexuses are located in the lateral and 4th ventricles. It then travels to the subarachnoid space via the medial and lateral apertures and is reabsorbed by ________ ________ and then drains into dural venous sinuses.

Answer 11

Arachnoid Granulations

Question 12

In an axial CT, if you can see the lateral ventricles then you know you are at what level of the brain?

Answer 12

Telencephalon and Cerebral Cortex area

Question 13

In an axial CT, if you can see the 3rd ventricle then you know you are at what level of the brain?

Answer 13

Level of Thalamus

Question 14

In an axial CT, if you can see the 4th ventricle then you know you are at what level of the brain?

Answer 14

Level of Pons

Question 15

This is the term for increased amounts of intracranial pressure and ventricular dilation due to an excessive amount of CSF accumulation in the ventricles and/or subarachnoid spaces.

Answer 15

Hydrocephalus

Question 16

Hydrocephalus can be congenital OR acquired due to…

Answer 16

1) Overproduction of CSF (rare)
2) Under-absorption of CSF
3) Obstruction of outflow

Question 17

Overproduction of CSF or under-absorption of CSF are both (NON-COMMUNICATING/COMMUNICATING) and (NON-OBSTRUCTIVE/OBSTRUCTIVE).

Answer 17

Communicating

Non-obstructive

Question 18

Obstruction of outflow is (NON-COMMUNICATING/COMMUNICATING) and (NON-OBSTRUCTIVE/OBSTRUCTIVE).

Answer 18

Non-communicating

Obstructive

Question 19

This is due to an accumulation of CSF in the lateral and 3rd ventricles due to an obstruction. It is non-communicating (obstructive).

Answer 19

Aqueductal Stenosis

***The Cerebral Aqueduct (drains 3rd ventricle into 4th ventricle) is being blocked!

Question 20

What are the possible causes of Aqueductal Stenosis?

Answer 20

1) Congenital (most common cause)
2) Tumor (pineal)
3) Previous case of meningitis (or other infection) leading to scarring
4) Inflammation from intrauterine infection (current meningitis)

Question 21

This is a form of communicating (non-obstructive) hydrocephalus that occurs when CSF fails to drain properly, leading to enlarged ventricles and cortical atrophy. Patients present with the triad of:

1) Cognitive impairment/confusion
2) Unsteady, magnetic gait
3) Urinary incontinence

Answer 21

Normal Pressure Hydrocephalus

***WET - WACKY - WOBBLY

Question 22

What can cause Normal Pressure Hydrocpehalus?

Answer 22

• • Increased CSF viscosity
• • Altered elasticity of ventricular walls
• • Impaired CSF absorption (i.e., arachnoid granulations)

Question 23

What could possibly resolve Normal Pressure Hydrocephalus?

Answer 23

Lumbar puncture, because you take out fluid and release some of the pressure. If the patient goes too long though, the cortex can start to atrophy from the pressure and some of the effects could be irreversible.

Question 24

This is a non-communicating (obstructive) congenital hydrocephalus brain malformation where the 4th ventricle outlet is obstructed, causing the 4th ventricle to be enlarged and fluid to accumulate above it. It causes cerebellar hypoplasia, specifically partial or complete agenesis of the vermis.

Answer 24

Dandy-Walker Malformation

Question 25

This is a form of non-communicating (obstructive) hydrocephalus that causes the downward displacement of the inferior cerebellar vermis and tonsils through the foramen magnum. This causes the 4th ventricle outlet to be closed off, so fluid accumulates above it. It is closely associated with lumbosacral myelomeningocele.

Answer 25

Chiari II

Question 26

How is a tonsillar herniation and Chiari II different?

Answer 26

Chiari II is congenital, while a tonsillar herniation is due to increased intracranial pressure.

Question 27

What is the most common treatment for hydrocephalus?

Answer 27

Shunt

Question 28

A _______ is placed so that the fluid can drain to another part of the body. It contains a valve that keeps the fluid flowing in the right direction and at the correct speed. Most people will need this for the rest of their lives.

Answer 28

Shunt

Question 29

In hydrocephalus, the ventricles (PROXIMAL/DISTAL) to the obstruction/problem will enlarge.

Answer 29

Proximal

Question 30

If all ventricles are enlarged (generally, unless a post 4th ventricle obstruction) think about there being an _________ issue.

Answer 30

Absorption