7. CSF & Hydrocephalus

Question 1

What are the fxns of CSF

Answer 1

• provide homeostasis & mechanical protection/buoyancy
• removes brain metabolites (prevent bacterial spread; let ABs thru)
• hormone transport (endocrine fxn)

Question 2

Where is CSF made

Answer 2

primarily by choroid plexus, ependymal cells (60-80%)

-found in lateral ventricle (65%), 3rd & 4th ventricles

Question 3

What is the structure of choroid plexus

Answer 3

• villous folds lined by epithelium w/ central core of highly vascularized CT
• contains specialized layer of ependymal cells = choroidal epithelium overlies the villi (this dicates what goes in and out)

Question 4

Compare/contrast CSF and plasma

Answer 4

CSF = clear/colorless w few cells and low protein

-doesnt differ from plasma qualitatively, but it does QUANTITATIVELY

Question 5

CSF in bacterial meningitis

Answer 5

increased pressure (lumbar punture pressure)

increased PMNs (fighting bacteria) & protein (bacteria in cell & made of protein –> increase protein)

decreased glucose (bacteria eats glucose to stay alive)

Question 6

CSF in fungal/TB meningitis

Answer 6

increased pressure (lumbar punture pressure)

increased lymphocytes (fighting foreign particles) and protein (fungi made of protein –> increase protein levels when in cell)

decreased glucose (eat glucose to stay alive)

Question 7

CSF in viral meningitis

Answer 7

normal/increased pressure (lumbar punture pressure)

increased lymphocyte (fighting foreign particles)

normal/increased proteins (virus = very small; may not see increase)

normal glucose (virus is NOT living - depends on host to stay alive)

Question 8

What is the flow of CSF in the ventricular system

Answer 8

lateral ventricles –> 3rd ventricle by right/left interventricular foramina of monro –> 4th ventricle via cerebral aqueduct of sylvius –> subarachnoid space via foramina of Luschka (lateral) & foramen of Magendie (medial)

-then reabsorbed by arachnoid granulations and then drains into dural vnous sinuses

Question 9

label

Answer 9

Question 10

define hydrocephalus

Answer 10

increased intracranial pressure (ICP) and ventricular dilation due to excess amount of CSF build up in ventricles &/or subarachnoid spaces

Question 11

What are the causes of hydrocephalus

Answer 11

Congenital or Acquired

1. Communicating (non-obstructive): overproduction of CSF OR under-absorption of CSF
2. Non-communicating (obstructive): obstruction of outflow

Question 12

What is aqueductal stenoisis

Answer 12

Non-communicating (obstructive)

• Accumulation of CSF in lateral & third ventricles due to obstruction

Question 13

What are the causes of aqueductal stenosis

Answer 13

1. Congenital (most common ; x-linked)
2. Tumor (pineal)
3. Previous/current case of meningitis leading to scarring or other infection
4. Inflammation from intrauterine infection

treat: resolve meningitis or place shunt

Question 14

What type of hydrocephalus occurs in adults bc CSF doesnt drain properly and causes enlarged lateral ventricles and cortical atrophy

Answer 14

normal pressure hydrocephalus

= communicating hydrocephalus

-may resolve w/ lumbar puncture, b/c taking CSF out

Question 15

What are the causes of normal pressure hydrocephalus

Answer 15

1. increased CSF viscosity
2. altered elasticity of ventricular walls
3. impaired CSF absorption

Question 16

What is “wacky, wobbly and wet?”

Answer 16

the TRIAD that presents with normal pressure hydrocephalus

Wacky = cognitive impairment/confusion

Wobbly = unsteady/magnetic gait

Wet = urinary incontinence

Question 17

What is Dandy-Walker Malformation

Answer 17

Congenital: 4th ventricle outlet obstruction (enlarged- press on cerebellum))

Causes –> Cerebellar hypoplasia => partial or complete agenesis of vermis

fluid accumulates above 4th ventricle

=non-communicating

Question 18

What is Chiari II

Answer 18

• Downward displaced inferior cerebellar vermis & tonsils thru the foramen magnum
• Associated with lumbosacral myelomeningocele
• = non communicating
• build up above 4th ventricle

Question 19

What is the treatment for Chiari II

Answer 19

Most common = Shunt - placed so fluid can drain to another part of the body

shunt contains valves that keep the fluid flowing in the right direction and correct speed

usually need it for the rest of their life

Question 20

Areas proximal to the obstruction/problem—-

Answer 20

will enlarge

Question 21

If all ventricles are ______ (generally unless a past 4th ventricle obstruction), you should think __________

Answer 21

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

Question 22

lumbar punture is for….

Answer 22

=testing CSF via lumbar puncture (L4-L5)

-you know there is problem when CSF is yellow or has RBCs (after first tube)

Question 23

how do you know you’re at the level of the telencehpalon/cerebral cortex from a slide

Answer 23

see the lateral ventricle

Question 24

what structure will you see on the slide at the level of the thalami

Answer 24

see 3rd ventricle

Question 25

when you see the 4th ventricle you know youre at which level…

Answer 25

level of pons

Question 26

how are dandy-walker malformation and chiari II similar and diff

Answer 26

similar: fluid build up in 4th ventricle

dandy walker: cerebellum is not developed (problem in embryo)

chiari II: cerebellum is developed but pushed down