Lecture 7: Ventricles and CSF

Question 1

What is a big difference between Dandy Walker and Chiari Type II malformations?

Answer 1

• Dandy Walker: cerebellum not fully formed
• Chiari Type II: cerebellum formed

Question 2

What ventricles would be enlarged in Aqueductal stenosis?

Answer 2

Lateral and 3^rd Ventricles due to obstruction of cerebral aqueduct

Question 3

Where is the problem in a normal pressure hydrocephalus?

Answer 3

CSF fails to drain properly, leading to enlarged ventricles and cortical atrophy

• Increased CSF viscosity
• Alterted viscosity of ventricular walls
• Impaired CSF absorption by arachnoid villi

Communicating (Non-obstructive)

Question 4

What occurs in a Chiari II malformation?

Answer 4

• Displacement of inferior cerebellar vermis and tonsils through the foramen magnum
• Lumbosacral myelomeningocele
• Fluid accumulates above 4^th ventricle

Question 5

What are some symptoms of Normal Pressure Hydrocephalus?

Answer 5

Triad

• Cognitive impairment (wacky)
• Unsteady, magnetic gait (wobbly)
• Urinary incontinence (wet)

Question 6

What is the flow of CSF?

Be Specific

Answer 6

• Step 1: Lateral Ventricle –> 3^rd Ventricle
  
  • via Foramen of Monro
• Step 2: 3^rd Ventricle –> 4^th Ventricle
  
  • via Cerebral Aqueduct
• Step 3: 4^th Ventricle –> Subrachnoid Space
  
  • Lateral: Foramen of Luschka (2)
  • Medial: Foramen of Magendie (1)
• Step 4: Reabsorbed by arachnoid granulations
• Step 5: Drainage into dural venous sinuses

Question 7

If all the ventricles are enlarged, what type of issue should we think about?

Answer 7

Problem with Absorption of CSF

Question 8

What is happening in this image?

Is this communicative or non-communicative

Answer 8

Chiari II Malformation

Non-communicating (Obstructive)

Question 9

What is this?

Answer 9

Aqueductal Stenosis

Question 10

75 y/o male patient presents with progressive gait apraxia, memory loss, and urinary incontinence for the past few months. What kind of hydrocephalus does he most likely have?

Answer 10

Chronic Communicating Hydrocephalus

Normal Pressure Hydrocephalus

Question 11

2 y/o male patient presents with enlarged head and decreasing consciousness. On exam, he has papilledema and difficulty looking up. What type of hydocephalus might this patient have?

Answer 11

Aqueductal stenosis

Non-communicating (obstructive)

Question 12

When viewing a CT, what can the three differnet ventricles tell you about what level of the brain you are looking at?

Answer 12

• Lateral Ventricle: Telencephalon Structures
  
  • Cerebral Cortex
• Third Ventricle: Level of Thalami
• Fourth Ventricle: Pons

Question 13

What layer of the BBB controls entry of neurotransmitters?

Answer 13

Endothelium

Question 14

What is this?

Answer 14

Communicating Hydrocephalus at the level of lateral ventricle

Question 15

What is hydrocephalus?

Answer 15

Increased amounts of intracranial pressure and ventricular dilation tue to an excessive amount of CSF in ventricles and/or subaracnoid spaces

Question 16

What layer of the Blood-CSF barrier controls passage of substances?

Answer 16

Choroid cells

Question 17

Why is Dandy Walker Malformation considered a congenital problem?

Answer 17

• Problems start between 13^th-18^th week of development
• Cyst forms in 4th ventricle, disrupting development of cerebellum

Question 18

What is this?

Is this communicatinng or non-communicating?

Answer 18

Dandy Walker Malformation

Non-communicating (Obstructive)

Question 19

What are some causes of aqueductal stenosis?

Answer 19

• Congenital (x-linked)
• Pineal Tumor
• Meningitis Infection
• Inflammation from inrauterine infection

Can treat with shunt or cure infection

Question 20

Where is the majority of the CSF produced?

Answer 20

Lateral Ventricle (65%)

Question 21

What are symptoms of a Dandy Walker Malformation?

Answer 21

Congenital Brain Malformation

• Enlarged 4^th ventricle
  
  • fluid accumulates above this ventricle
• Cerebellar hypoplasia: agenesis of vermis of cerebellum
• Enlargement at the base of the skull in the posterior fossa

Question 22

What is the difference between communicating vs non-communicating hydrocephalus?

Answer 22

• Communicating (Non-Obstructive) Hydrocephalus
  
  • Due to overproduction (rare) or under-absorption of CSF (more common)
  • Occurs when the flow of CSF is blocked after it exits the ventricles. (CSF can still flow between the ventricles, which remain open)
• Non-Communicating (Obstructive) Hydrocephalus
  
  • ​Obstruction of outflow
  • CSF is blocked along one or more of the narrow passages connecting the ventricles