Practical 2: CSF Circulation (IMPORTANT)

Question 1

Differences between blood and CSF?

Answer 1

o CSF has fewer cells
o CSF has less protein
o CSF has lower concentration of K+ and Ca2+
o CSF has higher concentration of magnesium and chloride

Question 2

Volume and flow rate of CSF?

Answer 2

o Volume: 150 mL

o Flow: 500 mL/day

Question 3

Hydrocephalus is?
\_\_\_\_\_\_ - all 4 ventricles are affected 
o	Caused by \_\_\_\_\_\_\_\_\_ over the brain:
•	
•	
•	
•	

\_\_\_\_\_\_\_ - not all ventricles enlarged
o	Cause: \_\_\_\_\_ caused by:
•	
•	
•	

Signs and Symptoms:
1.
2.
3.
4.
5.

Treatment:
1.
2.
3.

Answer 3

Hydrocephalus: an abnormal increase in the amount of cerebrospinal fluid within the ventricles in the brain
COMMUNICATING - all 4 ventricles are affected
o Caused by block in CSF absorption or CSF flow over the brain:
• Meningitis
• Head Injury
• Congenital
• Haemorrhage (sub-arachnoid)

NON-COMMUNICATING - not all ventricles enlarged
o	Cause: block in the ventricular system caused by:
•	Aqueduct stenosis 
•	Ventricular tumours 
•	Paraventricular tumours 

Signs and Symptoms:
o	Headache 
o	Drowsiness
o	Blackouts 
o	Raised intracranial pressure
o	Increased head circumference (in children)

Treatment:
o	Remove cause e.g. papilloma
o	Divert CSF e.g. shunt
o	Open alternative pathway e.g. ventriculostomy

Question 4

• Meninges
o EPIDURAL/EXTRADURAL HAEMORRHAGE - usually _______ between the _______
o SUBDURAL HAEMORRAHGE - usually due to _____between the _____

o Distinguishing between the two:
• Epidural - symptoms arise ____
• Subdural - symptoms ____

•	Meningitis
o	Structures affected: \_\_\_ and \_\_\_\_
o	CSF analysis used to distinguish between bacterial and viral:
•	BACTERIAL
1.
2.
3.
4.
5.

•	VIRAL
1.
2.
3.
4.
5.

Answer 4

• Meninges
o EPIDURAL/EXTRADURAL HAEMORRHAGE - usually due to a damaged meningeal artery between the skull and the dura after head trauma
o SUBDURAL HAEMORRAHGE - usually due to a damaged vein between the dura and arachnoid membrane
o Distinguishing between the two:
• Epidural - symptoms arise promptly after the bleeding begins
• Subdural - symptoms may be delayed
• Meningitis
o Structures affected: Pia Mater and Subarachnoid Space
o CSF analysis used to distinguish between bacterial and viral:
• BACTERIAL
♣ HIGH WBC count
♣ NEUTROPHILS predominate
♣ Protein concentration = INCREASED
♣ Glucose concentration = INCREASED
♣ Bacteria may be identifiable - cloudy CSF
• VIRAL
♣ HIGH WBC count
♣ LYMPHOCYTES predominate
♣ Protein concentration = normal
♣ Glucose concentration = normal
♣ Viral identification is unlikely