Hydrocephalus

Question 1

What is CSF

Answer 1

ultra filtrate of plasma Fluid found in ventricles and subarachnoid space.
75ml in cranial and 75 in spinal canal

Question 2

What produced CSF

Answer 2

produced in brain by modified ependymal cells that form choroid plexus

Question 3

What produces CSF

Answer 3

Produced in brain by modified ependymal cells that form choroid plexus primarily in the lateral ventricles , but in other ventricles too . 10-30 pls produced an hour, replaced 4 times a day.

Question 4

What does the CSF consist of

Answer 4

Sodium , chloride , bicarbonate , magnesium , potassium , calcium , glucose , protein , pCO2 , pO2 , pH , white cells

Question 5

If you are suspecting bacterial meningitis what component of CSF will be different

Answer 5

Glucose will be less than 50% of serum level rather than the normal 60%

Question 6

Should there be any white cells in the CSF

Answer 6

Anything more than 5 then be suspicious of infection

Question 7

Explain how CSF is produced

Answer 7

Choroid plexus is responsible for 70 - 90% of CSF. Choroid plexus found in lateral ventricles , third ventricle and fourth ventricle. Highly vascular and produces CSF by active ATP dependent process.

Question 8

What medication can reduce CSF production

Answer 8

Acetazolamide ( carbonic anhydrase inhibitor ), remifentanil and noradrenaline

Question 9

What can increase CSF production

Answer 9

Volatile anesthetic agents , nitric oxide and hypercapnoea

Question 10

Where does the CSF drain out of

Answer 10

Foramina in 4th ventricle. Drains into the dural venous sinus via subarachnoid space

Question 11

Where does the CSF drain out of

Answer 11

Foramen in 4th ventricle

Question 12

Flow of CSF is dependent on what

Answer 12

Pressure

Question 13

Raised venous pressure results in what happening to the CSF

Answer 13

Reduced absorption which will cause back flow of CSF from the sinuses

Question 14

What is Hydrocephalus

Answer 14

Increase in CSF in head to point where brain can not properly function with raised pressure.
More common in children than adults

Question 15

If hydrocephalus left untreated what could happen

Answer 15

Developmental delay , neurological deficits , cognitive disorders and death

Question 16

What is the cause of Hydrocephalus

Answer 16

1- Communicating : blockage to CSF reabsorption in arachnoid granulations usually due to overproduction or defective absorption ( CSF can still flow between the ventricles but not into spinal canal)

2- Non-communicating : blockage within the CSF pathway ( can’t flow between ventricles )

3- Congenital : spina bifida , stenosis

4- acquired : infection , tumour ,SAH

Question 17

What is the cause of Hydrocephalus

Answer 17

Overproduction of CSF or CSF pathway obstruction

Question 18

What could cause non- communicating hydrocephalus

Answer 18

1- Colloid cyst
2- Pineal tumour
3- Wth ventricular tumour

Question 19

Presentation of patient with hydrocephalus

Answer 19

Infants 
1- Macrocrania 
2- recurring committing / poor feeding 
3- sunsetting eyes or gaze 
4- abnormal cry 
5- recurrent apnoea / pneumonia or stridor 
6- bradycardia 

Older children / adults 
1- Headache 
2- vomiting 
3- confusion / reduced consciousness 
4- Diplopia / cranial nerve palsies ( 3 , 4, 6 ) 
5- ataxia 
6- urinary incontinence 
7- dementia 
8- bradycardia 
9- hypertension

Question 20

Presentation of patient with hydrocephalus

Answer 20

Infants 
1- Macrocrania 
2- recurring committing / poor feeding 
3- sunsetting eyes or gaze 
4- abnormal cry 
5- recurrent apnoea / pneumonia or stridor 
6- bradycardia 

Older children / adults 
1- Headache 
2- vomiting 
3- confusion / reduced consciousness 
4- Diplopia / cranial nerve palsies 
5- ataxia 
6- urinary incontinence 
7- dementia 
8- bradycardia 
9- hypertension

Question 21

What is macro crania

Answer 21

abnormal increase in skull size = making facial area disproportionately small

Question 22

What hydrocephalus sign can a fundoscopy show

Answer 22

Papilloedema

Question 23

What is investigations are required for hydrocephalus

Answer 23

CT or MRI scans

Question 24

What will you see in a CT scan for hydrocephalus

Answer 24

A lot of dark black fluid in the scan , enlarging the ventricles. ependymal of ventricles is being stretched and CSF is leaking out.

Question 25

Why does CSF leak out

Answer 25

Blockage will cause ependymal of ventricles to be stretched and thus CSF will leak out

Question 26

Does big ventricles always mean hydrocephalus

Answer 26

No , could just be CSF taking up space of brain atrophy ( happens as everyone ages )

Question 27

What is idiopathic intracranial hypertension

Answer 27

Disease effecting young , usually females that are overweight.
High pressure around brain that is associated with sight loss and damage to optic nerve

Question 28

How to manage Hydrocephalus

Answer 28

1- Ventricular shunt
2- Bypass blockage
3- Endoscopic third ventriculostomy

Question 29

Explain the use of ventricular shunts to treat hydrocephalus , and where they are usually located

Answer 29

Mechanical device (catheter) to divert CSF from brain by draining the ventricle and then drains fluid outside

1- external drains : for temporary hydrocephalus ( if condition causing hydrocephalus will improve )

Will put into
1- Peritoneum ( most popular )
2- Atria/SVC
3- Pleural space

Question 30

What are the side effect of the ventricular shunts

Answer 30

They might get blocked and could cause problems in the locations they drain into

Question 31

What is a Endoscopic Third Ventriculostomy

Answer 31

Endoscope is passed in through the lateral or third ventricle and a thin membrane is used to create a stoma or small opening is done at both of third ventricle for CSF bypass the blockage and drain into spinal cord .

Risk : risk that could damage basilar artery and cause stroke