Lecture 7: Ventricles and CSF Flashcards Preview

Year 1: 06. Neuro Exam 2 > Lecture 7: Ventricles and CSF > Flashcards

Flashcards in Lecture 7: Ventricles and CSF Deck (22)
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1
Q

Where is the majority of the CSF produced?

A

Lateral Ventricle (65%)

2
Q

What layer of the BBB controls entry of neurotransmitters?

A

Endothelium

3
Q

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

A

Choroid cells

4
Q

What is the flow of CSF?

Be Specific

A
  • Step 1: Lateral Ventricle –> 3rd Ventricle
    • via Foramen of Monro
  • Step 2: 3rd Ventricle –> 4th Ventricle
    • via Cerebral Aqueduct
  • Step 3: 4th 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
5
Q

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

A
  • Lateral Ventricle: Telencephalon Structures
    • Cerebral Cortex
  • Third Ventricle: Level of Thalami
  • Fourth Ventricle: Pons
6
Q

What is hydrocephalus?

A

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

7
Q

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

A
  • 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
8
Q

What is this?

A

Aqueductal Stenosis

9
Q

What ventricles would be enlarged in Aqueductal stenosis?

A

Lateral and 3rd Ventricles due to obstruction of cerebral aqueduct

10
Q

What are some causes of aqueductal stenosis?

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

Can treat with shunt or cure infection

11
Q

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?

A

Aqueductal stenosis

Non-communicating (obstructive)

12
Q

What is this?

A

Communicating Hydrocephalus at the level of lateral ventricle

13
Q

Where is the problem in a normal pressure hydrocephalus?

A

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)

14
Q

What are some symptoms of Normal Pressure Hydrocephalus?

A

Triad

  • Cognitive impairment (wacky)
  • Unsteady, magnetic gait (wobbly)
  • Urinary incontinence (wet)
15
Q

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?

A

Chronic Communicating Hydrocephalus

Normal Pressure Hydrocephalus

16
Q

What is this?

Is this communicatinng or non-communicating?

A

Dandy Walker Malformation

Non-communicating (Obstructive)

17
Q

What are symptoms of a Dandy Walker Malformation?

A

Congenital Brain Malformation

  • Enlarged 4th ventricle
    • fluid accumulates above this ventricle
  • Cerebellar hypoplasia: agenesis of vermis of cerebellum
  • Enlargement at the base of the skull in the posterior fossa
18
Q

Why is Dandy Walker Malformation considered a congenital problem?

A
  • Problems start between 13th-18th week of development
  • Cyst forms in 4th ventricle, disrupting development of cerebellum
19
Q

What is happening in this image?

Is this communicative or non-communicative

A

Chiari II Malformation

Non-communicating (Obstructive)

20
Q

What occurs in a Chiari II malformation?

A
  • Displacement of inferior cerebellar vermis and tonsils through the foramen magnum
  • Lumbosacral myelomeningocele
  • Fluid accumulates above 4th ventricle
21
Q

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

A
  • Dandy Walker: cerebellum not fully formed
  • Chiari Type II: cerebellum formed
22
Q

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

A

Problem with Absorption of CSF